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| MCP1603 2.0 MHz, 500 mA Synchronous Buck Regulator Features * * * * * * * * * * * * * Over 90% Typical Efficiency Output Current Up To 500 mA Low Quiescent Current = 45 A, typical Low Shutdown Current = 0.1 A, typical Adjustable Output Voltage: - 0.8V to 4.5V Fixed Output Voltage: - 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V 2.0 MHz Fixed-Frequency PWM (Heavy Load) Automatic PWM to PFM Mode Transition 100% Duty Cycle Operation Internally Compensated Undervoltage Lockout (UVLO) Overtemperature Protection Space Saving Packages: - 5-Lead TSOT - 8-Lead 2X3 DFN General Description The MCP1603 is a high efficient, fully integrated 500 mA synchronous buck regulator whose 2.7V to 5.5V input voltage range makes it ideally suited for applications powered from 1-cell Li-Ion or 2-cell/3-cell NiMH/NiCd batteries. At heavy loads, the MCP1603 operates in the 2.0 MHz fixed frequency PWM mode which provides a low noise, low output ripple, small-size solution. When the load is reduced to light levels, the MCP1603 automatically changes operation to a PFM mode to minimize quiescent current draw from the battery. No intervention is necessary for a smooth transition from one mode to another. These two modes of operation allow the MCP1603 to achieve the highest efficiency over the entire operating current range. The MCP1603 is available with either an adjustable or fixed output voltage. The available fixed output voltage options are 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V. When a fixed option is used, only three additional small external components are needed to form a complete solution. Couple this with the low profile, small-foot print packages and the entire system solution is achieved with minimal size. Additional protection features include: overtemperature, and overcurrent protection. UVLO, Applications * * * * * * * Cellular Telephones Portable Computers Organizers / PDAs USB Powered Devices Digital Cameras Portable Equipment +5V or +3.3V Distributed Systems Package Types 5-Lead TSOT VIN GND SHDN 1 2 3 4 VFB/VOUT 5 LX SHDN GND LX 1 2 3 4 VIN 5 VFB/VOUT 8-Lead 2x3 DFN LX 1 NC 2 SHDN 3 VFB/VOUT 4 8 GND 7 VIN 6 NC 5 NC MCP1603 MCP1603L (c) 2007 Microchip Technology Inc. DS22042A-page 1 MCP1603 Typical Application Circuit VIN 2.7V To 4.5V VIN CIN 4.7 F LX COUT 4.7 F L1 4.7 H VOUT 1.8V @ 500 mA SHDN VFB GND 100 95 90 85 80 75 70 65 60 55 50 VOUT = 1.8V VIN = 3.6V VIN = 2.7V Efficiency (%) VIN = 4.5V 0.1 1 10 Output Current (mA) 100 1000 DS22042A-page 2 (c) 2007 Microchip Technology Inc. MCP1603 Functional Block Diagram VIN Band Gap Thermal Shutdown VREF UVLO Soft Start UVLO SHDN IPK Limit ILIMPWM ILIMPFM TSD IPEAKPWM IPEAKPFM Slope Comp OSC -ILPK S R Q Q POFF NOFF Switch Drive Logic and timing PWM/PFM LX PFM Error Amp PWM/PFM Logic GND VREF PWM Error Amp EA IPEAKPFM IPEAKPWM -ILPK -IPK Limit VREF OV Threshold Disable Switcher VFB / VOUT UV Threshold UVLO TSD (c) 2007 Microchip Technology Inc. DS22042A-page 3 MCP1603 1.0 ELECTRICAL CHARACTERISTICS Notice: Stresses above those listed under "Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operational sections of this specification is not intended. Exposure to maximum rating conditions for extended periods may affect device reliability. Absolute Maximum Ratings VIN - GND.......................................................................+6.0V All Other I/O ...............................(GND - 0.3V) to (VIN + 0.3V) LX to GND .............................................. -0.3V to (VIN + 0.3V) Output Short Circuit Current..................................Continuous Power Dissipation (Note 5) ..........................Internally Limited Storage Temperature.....................................-65C to +150C Ambient Temp. with Power Applied.................-40C to +85C Operating Junction Temperature...................-40C to +125C ESD Protection On All Pins: HBM..............................................................................4 kV MM...............................................................................300V DC CHARACTERISTICS Electrical Characteristics: Unless otherwise indicated, VIN = SHDN = 3.6V, COUT = CIN = 4.7 F, L = 4.7 H, VOUT(ADJ) = 1.8V, IOUT = 100 mA, TA = +25C. Boldface specifications apply over the TA range of -40C to +85C. Parameters Input Characteristics Input Voltage Maximum Output Current Shutdown Current Quiescent Current SHDN, Logic Input Voltage Low SHDN, Logic Input Voltage High SHDN, Input Leakage Current Undervoltage Lockout Sym VIN IOUT IIN_SHDN IQ VIL VIH IL_SHDN UVLO Min 2.7 500 -- -- -- 45 -1.0 2.12 -- -- -- Typ -- -- 0.1 45 -- -- 0.1 2.28 140 150 10 Max 5.5 -- 1 60 15 -- 1.0 2.43 -- -- -- Units V mA A A Note 1 Note 1 Conditions SHDN = GND SHDN = VIN, IOUT = 0 mA Shutdown/UVLO/Thermal Shutdown Characteristics %VIN VIN = 2.7V to 5.5V %VIN VIN = 2.7V to 5.5V A V mV C C Note 4, Note 5 Note 4, Note 5 VIN = 2.7V to 5.5V VIN Falling Undervoltage Lockout Hysteresis UVLOHYS Thermal Shutdown TSHD Thermal Shutdown Hysteresis Note 1: 2: 3: 4: TSHD-HYS 5: 6: The minimum VIN has to meet two conditions: VIN 2.7V and VIN VOUT + 0.5V. Reference Feedback Voltage Tolerance applies to adjustable output voltage setting. VR is the output voltage setting. The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable temperature and the thermal resistance from junction to air (i.e. TA, TJ, JA). Exceeding the maximum allowable power dissipation causes the device to initiate thermal shutdown. The internal MOSFET switches have an integral diode from the LX pin to the VIN pin, and from the LX pin to the GND pin. In cases where these diodes are forward-biased, the package power dissipation limits must be adhered to. Thermal protection is not able to limit the junction temperature for these cases. The current limit threshold is a cycle-by-cycle peak current limit. DS22042A-page 4 (c) 2007 Microchip Technology Inc. MCP1603 DC CHARACTERISTICS (CONTINUED) Electrical Characteristics: Unless otherwise indicated, VIN = SHDN = 3.6V, COUT = CIN = 4.7 F, L = 4.7 H, VOUT(ADJ) = 1.8V, IOUT = 100 mA, TA = +25C. Boldface specifications apply over the TA range of -40C to +85C. Parameters Output Characteristics Adjustable Output Voltage Range Reference Feedback Voltage Reference Feedback Voltage Tolerance Feedback Input Bias Current Output Voltage Tolerance Fixed Line Regulation Load Regulation Internal Oscillator Frequency Start Up Time RDSon P-Channel RDSon N-Channel LX Pin Leakage Current Positive Current Limit Threshold Note 1: 2: 3: 4: Sym VOUT VFB Min 0.8 -- -3.0 -2.5 Typ -- 0.8 -- -- 0.1 VR VR 0.3 0.35 2.0 0.6 500 500 0.1 860 Max 4.5 -- +3.0 +2.5 -- +3.0% +2.5 -- -- 2.8 -- -- -- 1.0 -- Units V V % % nA % % %/V % MHz ms m m A mA Note 2 Conditions TA = -40C to +25C TA = +25C to +85C TA = -40C to +25C, Note 3 TA = +25C to +85C, Note 3 VIN = VR + 1V to 5.5V, IOUT = 100 mA VIN = VR +1.5V, ILOAD = 100 mA to 500 mA TR = 10% to 90% IP = 100 mA IN = 100 mA SHDN = 0V, VIN = 5.5V, LX = 0V, LX = 5.5V Note 6 IVFB VOUT VOUT VLINEREG -- -3.0% -2.5 -- -- 1.5 -- -- -- -1.0 -- VLOADREG FOSC TSS RDSon-P RDSon-N ILX +ILX(MAX) 5: 6: The minimum VIN has to meet two conditions: VIN 2.7V and VIN VOUT + 0.5V. Reference Feedback Voltage Tolerance applies to adjustable output voltage setting. VR is the output voltage setting. The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable temperature and the thermal resistance from junction to air (i.e. TA, TJ, JA). Exceeding the maximum allowable power dissipation causes the device to initiate thermal shutdown. The internal MOSFET switches have an integral diode from the LX pin to the VIN pin, and from the LX pin to the GND pin. In cases where these diodes are forward-biased, the package power dissipation limits must be adhered to. Thermal protection is not able to limit the junction temperature for these cases. The current limit threshold is a cycle-by-cycle peak current limit. (c) 2007 Microchip Technology Inc. DS22042A-page 5 MCP1603 TEMPERATURE SPECIFICATIONS Electrical Specifications: Unless otherwise indicated, all limits are specified for: VIN + 2.7V to 5.5V Parameters Temperature Ranges Operating Junction Temperature Range Storage Temperature Range Maximum Junction Temperature Package Thermal Resistances Thermal Resistance, 5L-TSOT Thermal Resistance, 8L-2x3 DFN JA JA -- -- 256 84.5 -- -- C/W C/W Typical 4-layer Board with Internal Ground Plane Typical 4-layer Board with Internal Ground Plane and 2-Vias in Thermal Pad TJ TA TJ -40 -65 -- -- -- -- +125 +150 +150 C C C Transient Steady State Sym Min Typ Max Units Conditions DS22042A-page 6 (c) 2007 Microchip Technology Inc. MCP1603 2.0 Note: TYPICAL PERFORMANCE CURVES The graphs and tables provided following this note are a statistical summary based on a limited number of samples and are provided for informational purposes only. The performance characteristics listed herein are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified operating range (e.g., outside specified power supply range) and therefore outside the warranted range. Note: Unless otherwise indicated, VIN = SHDN = 3.6V, COUT = CIN = 4.7 F, L = 4.7 H, VOUT(ADJ) = 1.8V, ILOAD = 100 mA, TA = +25C. Adjustable or fixed output voltage options can be used to generate the Typical Performance Characteristics. 50 49 48 47 46 45 44 43 42 41 40 52 Quiescent Current (A) 50 48 46 44 42 40 -40 -25 -10 5 20 35 50 65 80 o Quiescent Current (A) VOUT = 1.8V VIN = 3.6V VIN = 4.2V TA = +90 C o TA = +25 C o VIN = 3.0V TA = - 40 C o 95 110 125 2.7 3.05 3.4 3.75 4.1 4.45 4.8 5.15 5.5 Ambient Temperature ( C) Input Voltage (V) FIGURE 2-1: 100 95 Efficiency (%) 90 85 80 75 70 65 60 2.7 3.05 3.4 IOUT = 100 mA IQ vs. Ambient Temperature. FIGURE 2-4: 100 IQ vs. Input Voltage. VOUT = 1.2V VOUT = 1.2V 90 Efficiency (%) 80 70 60 50 40 30 20 VIN = 2.7V VIN = 3.6V IOUT = 300 mA IOUT = 500 mA VIN = 4.2V 3.75 4.1 4.45 4.8 5.15 5.5 0.1 1 10 100 1000 Input Voltage (V) Output Current (mA) FIGURE 2-2: (VOUT = 1.2V). 100 95 Efficiency (%) 90 85 80 75 70 2.7 3.05 3.4 IOUT = 100 mA Efficiency vs. Input Voltage FIGURE 2-5: (VOUT = 1.2V). 100 90 Efficiency (%) 80 70 60 50 40 30 20 VIN = 4.2V Efficiency vs. Output Load VOUT = 1.8V VIN = 2.7V VIN = 3.6V IOUT = 300 mA IOUT = 500 mA VOUT = 1.8V 3.75 4.1 4.45 4.8 5.15 5.5 0.1 1 10 100 1000 Input Voltage (V) Output Current (mA) FIGURE 2-3: (VOUT = 1.8V). Efficiency vs. Input Voltage FIGURE 2-6: (VOUT = 1.8V). Efficiency vs. Output Load (c) 2007 Microchip Technology Inc. DS22042A-page 7 MCP1603 Typical Performance Curves (Continued) Note: Unless otherwise indicated, VIN = SHDN = 3.6V, COUT = CIN = 4.7 F, L = 4.7 H, VOUT(ADJ) = 1.8V, ILOAD = 100 mA, TA = +25C. Adjustable or fixed output voltage options can be used to generate the Typical Performance Characteristics. 100 95 Efficiency (%) 90 85 80 75 3 3.5 4 4.5 5 5.5 Input Voltage (V) IOUT = 100 mA VOUT = 2.4V 100 90 Efficiency (%) 80 70 60 50 40 30 0.1 1 10 100 1000 Output Current (mA) VIN = 4.2V VOUT = 2.4V VIN = 2.7V VIN = 3.6V IOUT = 300 mA IOUT = 500 mA FIGURE 2-7: (VOUT = 2.4V). 100.0 97.5 Efficiency (%) 95.0 92.5 90.0 87.5 85.0 3.5 3.75 4 Efficiency vs. Input Voltage FIGURE 2-10: (VOUT = 2.4V). 100 90 Efficiency (%) 80 70 60 50 40 VIN = 4.2V VIN = 3.6V Efficiency vs. Output Load VOUT = 3.3V IOUT = 100 mA IOUT = 300 mA IOUT = 500 mA VOUT = 3.3V 4.25 4.5 4.75 Input Voltage (V) 5 5.25 5.5 30 0.1 1 10 100 1000 Output Current (mA) FIGURE 2-8: (VOUT = 3.3V). 0.6 Line Regualtion (%/V) 0.5 Efficiency vs. Input Voltage FIGURE 2-11: (VOUT = 3.3V). 1.82 1.81 Output Voltage (V) 1.80 1.79 1.78 1.77 1.76 1.75 1.74 100 Efficiency vs. Output Load VOUT = 1.8V IOUT = 300 mA TA = +125 C o TA = +90 C o 0.4 0.3 0.2 0.1 -40 -25 -10 5 20 35 50 65 80 95 110 125 o TA = - 40 C o TA = +25 C o IOUT = 100 mA 150 200 250 300 350 400 450 500 Ambient Temperature ( C) Output Current (mA) FIGURE 2-9: Line Regulation vs. Ambient Temperature (VOUT = 1.8V). FIGURE 2-12: Output Voltage vs. Load Current (VOUT = 1.8V). DS22042A-page 8 (c) 2007 Microchip Technology Inc. MCP1603 Typical Performance Curves (Continued) Note: Unless otherwise indicated, VIN = SHDN = 3.6V, COUT = CIN = 4.7 F, L = 4.7 H, VOUT(ADJ) = 1.8V, ILOAD = 100 mA, TA = +25C. Adjustable or fixed output voltage options can be used to generate the Typical Performance Characteristics. 2.20 2.15 2.10 2.05 2.00 1.95 -40 -25 -10 5 20 35 50 65 80 95 110 125 o Switching Frequency (MHz) Switching Frequency (MHz) 2.20 2.15 2.10 2.05 2.00 1.95 2.7 3.05 3.4 3.75 4.1 4.45 4.8 5.15 5.5 Input Voltage (V) Ambient Temperature ( C) FIGURE 2-13: Switching Frequency vs. Ambient Temperature. 0.65 Switch Resistance (m) FIGURE 2-16: Input Voltage. 0.9 Switch Resistance (m) 0.8 0.7 0.6 0.5 0.4 0.3 P-Channel Switching Frequency vs. 0.60 0.55 0.50 0.45 0.40 0.35 2.7 3.05 3.4 3.75 4.1 4.45 4.8 5.15 5.5 Input Voltage (V) P-Channel N-Channel N-Channel -40 -25 -10 5 20 35 50 65 80 o 95 110 125 Ambient Temperature ( C) FIGURE 2-14: Voltage. Switch Resistance vs. Input FIGURE 2-17: Switch Resistance vs. Ambient Temperature. FIGURE 2-15: Waveform. Output Voltage Startup FIGURE 2-18: Waveform. Heavy Load Switching (c) 2007 Microchip Technology Inc. DS22042A-page 9 MCP1603 Typical Performance Curves (Continued) Note: Unless otherwise indicated, VIN = SHDN = 3.6V, COUT = CIN = 4.7 F, L = 4.7 H, VOUT(ADJ) = 1.8V, ILOAD = 100 mA, TA = +25C. Adjustable or fixed output voltage options can be used to generate the Typical Performance Characteristics. FIGURE 2-19: Waveform. Light Load Switching FIGURE 2-21: Output Voltage Line Step Response vs. Time. FIGURE 2-20: Output Voltage Load Step Response vs. Time. DS22042A-page 10 (c) 2007 Microchip Technology Inc. MCP1603 3.0 PIN DESCRIPTIONS The descriptions of the pins are listed in Table 3-1. TABLE 3-1: MCP1603 TSOT23 1 2 3 4 5 -- -- PIN FUNCTION TABLE Pin No. MCP1603L TSOT23 4 2 1 5 3 -- -- 2x3 DFN 7 8 3 4 1 2, 5, 6 Exposed Pad Symbol VIN GND SHDN VFB/VOUT LX NC EP Power Supply Input Voltage Pin Ground Pin Shutdown Control Input Pin Feedback / Output Voltage Pin Switch Node, Buck Inductor Connection Pin No Connect For the DFN package, the center exposed pad is a thermal path to remove heat from the device. Electrically this pad is at ground potential and should be connected to GND Description 3.1 Power Supply Input Voltage Pin (VIN) 3.4 Feedback / Output Voltage Pin (VFB/VOUT) Connect the input voltage source to VIN. The input source must be decoupled to GND with a 4.7 F capacitor. 3.2 Ground Pin (GND) For adjustable output options, connect the center of the output voltage divider to the VFB/VOUT pin. For fixedoutput voltage options, connect the output directly to the VFB/VOUT pin. Ground pin for the device. The loop area of the ground traces should be kept as minimal as possible. 3.5 Switch Node, Buck Inductor Connection Pin (LX) 3.3 Shutdown Control Input Pin (SHDN) Connect the LX pin directly to the buck inductor. This pin carries large signal-level current; all connections should be made as short as possible. The SHDN pin is a logic-level input used to enable or disable the device. A logic high (> 45% of VIN) will enable the regulator output. A logic-low (< 15% of VIN) will ensure that the regulator is disabled. 3.6 Exposed Metal Pad (EP) For the DFN package, connect the Exposed Pad to GND, with vias into the GND plane. This connection to the GND plane will aid in heat removal from the package. (c) 2007 Microchip Technology Inc. DS22042A-page 11 MCP1603 4.0 4.1 DETAILED DESCRIPTION Device Overview 4.2 Synchronous Buck Regulator The MCP1603 is a synchronous buck regulator that operates in a Pulse Frequency Modulation (PFM) mode or a Pulse Width Modulation (PWM) mode to maximize system efficiency over the entire operating current range. Capable of operating from a 2.7V to 5.5V input voltage source, the MCP1603 can deliver 500 mA of continuous output current. When using the MCP1603, the PCB area required for a complete step-down converter is minimized since both the main P-Channel MOSFET and the synchronous N-Channel MOSFET are integrated. Also while in PWM mode, the device switches at a constant frequency of 2.0 MHz (typ) which allow for small filtering components. Both fixed and adjustable output voltage options are available. The fixed voltage options (1.2V, 1.5V 1.8V, 2.5V, 3.3V) do not require an external voltage divider which further reduces the required circuit board footprint. The adjustable output voltage options allow for more flexibility in the design, but require an external voltage divider. Additionally the device features undervoltage lockout (UVLO), overtemperature shutdown, overcurrent protection, and enable/disable control. The MCP1603 has two distinct modes of operation that allow the device to maintain a high level of efficiency throughout the entire operating current and voltage range. The device automatically switched between PWM mode and PFM mode depending upon the output load requirements. 4.2.1 FIXED FREQUENCY, PWM MODE During heavy load conditions, the MCP1603 operates at a high, fixed switching frequency of 2.0 MHz (typical) using current mode control. This minimizes output ripple (10 - 15 mV typically) and noise while maintaining high efficiency (88% typical with VIN = 3.6V, VOUT = 1.8V, IOUT = 300 mA). During normal PWM operation, the beginning of a switching cycle occurs when the internal P-Channel MOSFET is turned on. The ramping inductor current is sensed and tied to one input of the internal high-speed comparator. The other input to the high-speed comparator is the error amplifier output. This is the difference between the internal 0.8V reference and the divideddown output voltage. When the sensed current becomes equal to the amplified error signal, the highspeed comparator switches states and the P-Channel MOSFET is turned off. The N-Channel MOSFET is turned on until the internal oscillator sets an internal RS latch initiating the beginning of another switching cycle. PFM-to-PWM mode transition is initiated for any of the following conditions: * Continuous device switching * Output voltage has dropped out of regulation 4.2.2 LIGHT LOAD, PFM MODE During light load conditions, the MCP1603 operates in a PFM mode. When the MCP1603 enters this mode, it begins to skip pulses to minimize unnecessary quiescent current draw by reducing the number of switching cycles per second. The typical quiescent current draw for this device is 45 A. PWM-to-PFM mode transition is initiated for any of the following conditions: * Discontinuous inductor current is sensed for a set duration * Inductor peak current falls below the transition threshold limit DS22042A-page 12 (c) 2007 Microchip Technology Inc. MCP1603 4.3 Soft Start 4.6 Enable/Disable Control The output of the MCP1603 is controlled during startup. This control allows for a very minimal amount of VOUT overshoot during start-up from VIN rising above the UVLO voltage or SHDN being enabled. The SHDN pin is used to enable or disable the MCP1603. When the SHDN pin is pulled low, the device is disabled. When pulled high the device is enabled and begins operation provided the input voltage is not below the UVLO threshold or a fault condition exists. 4.4 Overtemperature Protection Overtemperature protection circuitry is integrated in the MCP1603. This circuitry monitors the device junction temperature and shuts the device off, if the junction temperature exceeds the typical 150C threshold. If this threshold is exceeded, the device will automatically restart once the junction temperature drops by approximately 10C. The soft start is reset during an overtemperture condition. 4.7 Undervoltage Lockout (UVLO) 4.5 Overcurrent Protection Cycle-by-cycle current limiting is used to protect the MCP1603 from being damaged when an external short circuit is applied. The typical peak current limit is 860 mA. If the sensed current reaches the 860 mA limit, the P-Channel MOSFET is turned off, even if the output voltage is not in regulation. The device will attempt to start a new switching cycle when the internal oscillator sets the internal RS latch. The UVLO feature uses a comparator to sense the input voltage (VIN) level. If the input voltage is lower than the voltage necessary to properly operate the MCP1603, the UVLO feature will hold the converter off. When VIN rises above the necessary input voltage, the UVLO is released and soft start begins. Hysteresis is built into the UVLO circuit to compensate for input impedance. For example, if there is any resistance between the input voltage source and the device when it is operating, there will be a voltage drop at the input to the device equal to IIN x RIN. The typical hysteresis is 140 mV. (c) 2007 Microchip Technology Inc. DS22042A-page 13 MCP1603 5.0 5.1 APPLICATION INFORMATION Typical Applications For adjustable output applications, an additional R-C compensation network is necessary for control loop stability. Recommended values for any output voltage are: RCOMP CCOMP = = 4.99 k 33 pF The MCP1603 500 mA synchronous buck regulator operates over a wide input voltage range (2.7V to 5.5V) and is ideal for single-cell Li-Ion battery powered applications, USB powered applications, three cell NiMH or NiCd applications and 3V or 5V regulated input applications. The 5-lead TSOT and 8-lead 2x3 DFN packages provide a small footprint with minimal external components. Refer to Figure 6-2 for proper placement of RCOMP and CCOMP. 5.4 Input Capacitor Selection 5.2 Fixed Output Voltage Applications Typical Application Circuit shows a fixed MCP1603 in an application used to convert three NiMH batteries into a well regulated 1.8V @ 500 mA output. A 4.7 F input capacitor, 4.7 F output capacitor, and a 4.7 H inductor make up the entire external component solution for this application. No external voltage divider or compensation is necessary. In addition to the fixed 1.8V option, the MCP1603 is also available in 1.2V, 1.5V, 2.5V, or 3.3V fixed voltage options. The input current to a buck converter, when operating in continuous conduction mode, is a squarewave with a duty cycle defined by the output voltage (VOUT) to input voltage (VIN) relationship of VOUT/VIN. To prevent undesirable input voltage transients, the input capacitor should be a low ESR type with an RMS current rating given by Equation 5.5. Because of their small size and low ESR, ceramic capacitors are often used. Ceramic material X5R or X7R are well suited since they have a low temperature coefficient and acceptable ESR. EQUATION 5-2: V OUT x ( V IN - V OUT ) I CIN ,RMS = I OUT ,MAX x ----------------------------------------------------- V IN Table 5-1 contains the recommend range for the input capacitor value. 5.3 Adjustable Output Voltage Applications When the desired output for a particular application is not covered by the fixed voltage options, an adjustable MCP1603 can be used. The circuit listed in Figure 6-2 shows an adjustable MCP1603 being used to convert a 5V rail to 1.0V @ 500 mA. The output voltage is adjustable by using two external resistors as a voltage divider. For adjustable-output voltages, it is recommended that the top resistor divider value be 200 k. The bottom resistor value can be calculated using the following equation: 5.5 Output Capacitor Selection EQUATION 5-1: The output capacitor helps provide a stable output voltage during sudden load transients, smooths the current that flows from the inductor to the load, and reduces the output voltage ripple. Therefore, low ESR capacitors are a desirable choice for the output capacitor. As with the input capacitor, X5R and X7R ceramic capacitors are well suited for this application. The output ripple voltage is often a design specification. A buck converters' output ripple voltage is a function of the charging and discharging of the output capacitor and the ESR of the capacitor. This ripple voltage can be calculated by Equation 5-3. V FB R BOT = R TOP x ---------------------------- V OUT - V FB Example: RTOP VOUT VFB RBOT RBOT = = = = = 200 k 1.0V 0.8V 200 k x (0.8V/(1.0V - 0.8V)) 800 k (Standard Value = 787 k) EQUATION 5-3: I L V OUT = I L x ESR + -------------------8xfxC DS22042A-page 14 (c) 2007 Microchip Technology Inc. MCP1603 Table 5-1 contains the recommend range for the output capacitor value. TABLE 5-2: Part Number Coiltronics(R) SD3110 SD3110 SD3110 SD3812 SD3812 SD3812 Wurth WE-TPC Type XS WE-TPC Type XS WE-TPC Type S WE-TPC Type S Sumida(R) CMD4D06 CMD4D06 CMD4D06 MCP1603 RECOMMENDED INDUCTORS Value (H) DCR (max) 0.195 0.285 0.346 0.159 0.256 0.299 0.225 0.290 0.105 0.156 ISAT (A) Size WxLxH (mm) TABLE 5-1: Minimum Maximum CAPACITOR VALUE RANGE CIN 4.7 F -- COUT 4.7 F 22 F 3.3 4.7 6.8 3.3 4.7 6.8 3.3 4.7 4.7 6.8 0.81 0.68 0.58 1.40 1.13 0.95 0.72 0.50 0.90 0.75 3.1x3.1x1.0 3.1x3.1x1.0 3.1x3.1x1.0 3.8x3.8x1.2 3.8x3.8x1.2 3.8x3.8x1.2 3.3x3.5x0.95 3.3x3.5x0.95 3.8x3.8x1.65 3.8x3.8x1.65 5.6 Inductor Selection When using the MCP1603, the inductance value can range from 3.3 H to 10 H. An inductance value of 4.7 H is recommended to achieve a good balance between converter load transient response and minimized noise. The value of inductance is selected to achieve a desired amount of ripple current. It is reasonable to assume a ripple current that is 20% of the maximum load current. The larger the amount of ripple current allowed, the larger the output capacitor value becomes to meet ripple voltage specifications. The inductor ripple current can be calculated according to the following equation. Elektronik(R) EQUATION 5-4: V OUT V OUT I L = ------------------ x 1 - ------------ F SW x L V IN Where: FSW = Switching Frequency When considering inductor ratings, the maximum DC current rating of the inductor should be at least equal to the maximum load current, plus one half the peak-topeak inductor ripple current (1/2 * IL). The inductor DC resistance adds to the total converter power loss. An inductor with a low DC resistance allows for higher converter efficiency. 3.3 4.7 6.8 0.174 0.216 0.296 0.77 0.75 0.62 3.5x4.3x0.8 3.5x4.3x0.8 3.5x4.3x0.8 5.7 Thermal Calculations The MCP1603 is available in two different packages (TSOT-23 and 2x3 DFN). By calculating the power dissipation and applying the package thermal resistance, (JA), the junction temperature is estimated. The maximum continuous junction temperature rating for the MCP1603 is +125C. To quickly estimate the internal power dissipation for the switching buck regulator, an empirical calculation using measured efficiency can be used. Given the measured efficiency, the internal power dissipation is estimated by: EQUATION 5-5: V OUT x I OUT - ( V -----------------------------OUT x I OUT ) = P Diss Efficiency The difference between the first term, input power dissipation, and the second term, power delivered, is the internal power dissipation. This is an estimate assuming that most of the power lost is internal to the MCP1603. There is some percentage of power lost in the buck inductor, with very little loss in the input and output capacitors. (c) 2007 Microchip Technology Inc. DS22042A-page 15 MCP1603 5.8 PCB Layout Information Good printed circuit board layout techniques are important to any switching circuitry and switching power supplies are no different. When wiring the high current paths, short and wide traces should be used. This high current path is shown with red connections in Figure 5-1. The current in this path is switching. Therefore, it is important that the components along the high current path should be placed as close as possible to the MCP1603 to minimize the loop area. The feedback resistors and feedback signal should be routed away from the switching node and this switching current loop. When possible ground planes and traces should be used to help shield the feedback signal and minimize noise and magnetic interference. VIN 2.7V To 4.5V VIN CIN 4.7 F LX L1 4.7 H VOUT 1.8V @ 500 mA SHDN VFB GND COUT 4.7 F FIGURE 5-1: PCB High Current Path. DS22042A-page 16 (c) 2007 Microchip Technology Inc. MCP1603 6.0 l TYPICAL APPLICATION CIRCUITS VIN 3.0V To 4.2V CIN 4.7 F L1 4.7 H VIN LX VOUT 1.5V @ 500 mA COUT 4.7 F SHDN VFB GND FIGURE 6-1: Single Li-Ion to 1.5V @ 500 mA Application. VIN 5.0V CIN 4.7 F L1 4.7 H VIN LX RTOP 200 k VFB RBOT 787 k RCOMP 4.99 k VOUT 1.0V @ 500 mA CCOMP 33 pF COUT 4.7 F SHDN GND FIGURE 6-2: 5V to 1.0V @ 500 mA Application. VIN 2.7V To 4.5V CIN 4.7 F L1 4.7 H VIN LX COUT 4.7 F VOUT 1.2V @ 500 mA SHDN VFB GND FIGURE 6-3: 3 NiMH Batteries to 1.2V @ 500 mA Application.9 (c) 2007 Microchip Technology Inc. DS22042A-page 17 MCP1603 7.0 7.1 PACKAGING INFORMATION Package Marking Information (Not to Scale) 8-Lead 2x3 DFN Part Number XXX YWW NNN Marking Code AFM AFK AFJ AFG AFA AFQ Example: MCP1603-120I/MC MCP1603-150I/MC MCP1603-180I/MC MCP1603-250I/MC MCP1603-330I/MC MCP1603-ADJI/MC AFM 711 25 5-Lead TSOT Part Number MCP1603T-120I/OS MCP1603T-150I/OS MCP1603T-180I/OS MCP1603T-250I/OS MCP1603T-330I/OS MCP1603T-ADJI/OS Part Number MCP1603LT-120I/OS MCP1603LT-150I/OS MCP1603LT-180I/OS MCP1603LT-250I/OS MCP1603LT-330I/OS MCP1603LT-ADJI/OS Marking Code ETNN EUNN EVNN EWNN EXNN EYNN Marking Code FMNN FKNN EJNN FGNN FANN FQNN Example XXNN ET25 Legend: XX...X Y YY WW NNN e3 * Note: Customer-specific information Year code (last digit of calendar year) Year code (last 2 digits of calendar year) Week code (week of January 1 is week `01') Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) This package is Pb-free. The Pb-free JEDEC designator ( e3) can be found on the outer packaging for this package. In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information. DS22042A-page 18 (c) 2007 Microchip Technology Inc. MCP1603 8-Lead Plastic Dual Flat, No Lead Package (MC) - 2x3x0.9 mm Body [DFN] Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging e N L D N b K E E2 EXPOSED PAD NOTE 1 1 2 D2 TOP VIEW BOTTOM VIEW 2 1 NOTE 1 A A3 A1 NOTE 2 Units Dimension Limits MIN MILLIMETERS NOM 8 0.50 BSC 0.80 0.00 0.90 0.02 0.20 REF 2.00 BSC 3.00 BSC 1.30 1.50 0.18 0.30 0.20 - - 0.25 0.40 - 1.75 1.90 0.30 0.50 - 1.00 0.05 MAX Number of Pins Pitch Overall Height Standoff Contact Thickness Overall Length Overall Width Exposed Pad Length Exposed Pad Width Contact Width Contact Length Contact-to-Exposed Pad N e A A1 A3 D E D2 E2 b L K Notes: 1. Pin 1 visual index feature may vary, but must be located within the hatched area. 2. Package may have one or more exposed tie bars at ends. 3. Package is saw singulated. 4. Dimensioning and tolerancing per ASME Y14.5M. BSC: Basic Dimension. Theoretically exact value shown without tolerances. REF: Reference Dimension, usually without tolerance, for information purposes only. Microchip Technology Drawing C04-123B (c) 2007 Microchip Technology Inc. DS22042A-page 19 MCP1603 5-Lead Plastic Thin Small Outline Transistor (OS) [TSOT] Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging b N E E1 NOTE 1 1 2 3 e e1 D A A2 c L L1 A1 Units Dimension Limits Number of Leads Lead Pitch Outside Lead Pitch Overall Height Molded Package Thickness Standoff Overall Width Molded Package Width Overall Length Foot Length Footprint Foot Angle Lead Thickness Lead Width Mold Draft Angle Top Mold Draft Angle Bottom N e e1 A A2 A1 E E1 D L L1 c b 0 0.08 0.30 4 4 0.30 - 0.70 0.00 MIN MILLIMETERS NOM 5 0.95 BSC 1.90 BSC - 0.90 - 2.80 BSC 1.60 BSC 2.90 BSC 0.45 0.60 REF 4 - - 10 10 8 0.20 0.50 12 0.60 1.10 1.00 0.10 MAX 12 Notes: 1. Pin 1 visual index feature may vary, but must be located within the hatched area. 2. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.15 mm per side. 3. Dimensioning and tolerancing per ASME Y14.5M. BSC: Basic Dimension. Theoretically exact value shown without tolerances. REF: Reference Dimension, usually without tolerance, for information purposes only. Microchip Technology Drawing C04-128B DS22042A-page 20 (c) 2007 Microchip Technology Inc. MCP1603 APPENDIX A: REVISION HISTORY Revision A (May 2007) * Original Release of this Document. (c) 2007 Microchip Technology Inc. DS22042A-page 21 MCP1603 NOTES: DS22042A-page 22 (c) 2007 Microchip Technology Inc. MCP1603 PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. Device X X XXX X / XX Examples: 8-Lead DFN: a) b) Device: TSOT Pin Config. Designator * MCP1603: 2.0 MHz, 500 mA Buck Regulator TSOT Tape Voltage Temp. Package Config. and Reel Option c) Blank = Standard pinout L = Alternate pinout * Refer to Package Types for an explanation regarding the function of the device pins. T Blank ADJ 120 150 180 250 330 I = = = = = = = Tape and Reel = Tube Adjustable 1.20V "Standard" 1.50V "Standard" 1.80V "Standard" 2.50V "Standard" 3.30V "Standard" d) e) MCP1603-120I/MC: 1.20V Buck Reg., 8LD-DFN pkg. MCP1603-150I/MC: 1.50V Buck Reg., 8LD-DFN pkg. MCP1603-180I/MC: 1.80V Buck Reg., 8LD-DFN pkg. MCP1603-250I/MC: 2.50V Buck Reg., 8LD-DFN pkg. MCP1603-330I/MC: 3.30V Buck Reg., 8LD-DFN pkg. MCP1603T-120I/OS: 1.20V Buck Reg., 5LD-TSOT pkg. MCP1603T-180I/OS: 1.80V Buck Reg., 5LD-TSOT pkg. MCP1603T-250I/OS: 2.50V Buck Reg., 5LD-TSOT pkg. MCP1603T-330I/OS: 3.30V Buck Reg., 5LD-TSOT pkg. MCP1603T-ADJI/OS: Adj. Buck Reg., 5LD-TSOT pkg. MCP1603LT-250I/OS:2.50V Buck Reg., 5LD-TSOT pkg. MCP1603LT-ADJI/OS:Adj. Buck Reg., 5LD-TSOT pkg. Tape and Reel: 5-Lead TSOT: a) b) c) d) e) f) g) Voltage Option: Temperature: Package Type: = -40C to +85C MC = Plastic Dual-Flat No-Lead Package (MC), 8-Lead OS = Plastic Thin Small Outline Transistor (OS), 5-Lead (c) 2007 Microchip Technology Inc. DS22042A-page 23 MCP1603 NOTES: DS22042A-page 24 (c) 2007 Microchip Technology Inc. Note the following details of the code protection feature on Microchip devices: * * * Microchip products meet the specification contained in their particular Microchip Data Sheet. Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip's Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. Microchip is willing to work with the customer who is concerned about the integrity of their code. Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as "unbreakable." * * Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our products. Attempts to break Microchip's code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act. Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights. Trademarks The Microchip name and logo, the Microchip logo, Accuron, dsPIC, KEELOQ, KEELOQ logo, microID, MPLAB, PIC, PICmicro, PICSTART, PRO MATE, rfPIC and SmartShunt are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. AmpLab, FilterLab, Linear Active Thermistor, Migratable Memory, MXDEV, MXLAB, SEEVAL, SmartSensor and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. Analog-for-the-Digital Age, Application Maestro, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, ECAN, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC, Mindi, MiWi, MPASM, MPLAB Certified logo, MPLIB, MPLINK, PICkit, PICDEM, PICDEM.net, PICLAB, PICtail, PowerCal, PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB, Select Mode, Smart Serial, SmartTel, Total Endurance, UNI/O, WiperLock and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. (c) 2007, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India. The Company's quality system processes and procedures are for its PIC(R) MCUs and dsPIC(R) DSCs, KEELOQ(R) code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip's quality system for the design and manufacture of development systems is ISO 9001:2000 certified. (c) 2007 Microchip Technology Inc. DS22042A-page 25 WORLDWIDE SALES AND SERVICE AMERICAS Corporate Office 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7200 Fax: 480-792-7277 Technical Support: http://support.microchip.com Web Address: www.microchip.com Atlanta Duluth, GA Tel: 678-957-9614 Fax: 678-957-1455 Boston Westborough, MA Tel: 774-760-0087 Fax: 774-760-0088 Chicago Itasca, IL Tel: 630-285-0071 Fax: 630-285-0075 Dallas Addison, TX Tel: 972-818-7423 Fax: 972-818-2924 Detroit Farmington Hills, MI Tel: 248-538-2250 Fax: 248-538-2260 Kokomo Kokomo, IN Tel: 765-864-8360 Fax: 765-864-8387 Los Angeles Mission Viejo, CA Tel: 949-462-9523 Fax: 949-462-9608 Santa Clara Santa Clara, CA Tel: 408-961-6444 Fax: 408-961-6445 Toronto Mississauga, Ontario, Canada Tel: 905-673-0699 Fax: 905-673-6509 ASIA/PACIFIC Asia Pacific Office Suites 3707-14, 37th Floor Tower 6, The Gateway Habour City, Kowloon Hong Kong Tel: 852-2401-1200 Fax: 852-2401-3431 Australia - Sydney Tel: 61-2-9868-6733 Fax: 61-2-9868-6755 China - Beijing Tel: 86-10-8528-2100 Fax: 86-10-8528-2104 China - Chengdu Tel: 86-28-8665-5511 Fax: 86-28-8665-7889 China - Fuzhou Tel: 86-591-8750-3506 Fax: 86-591-8750-3521 China - Hong Kong SAR Tel: 852-2401-1200 Fax: 852-2401-3431 China - Qingdao Tel: 86-532-8502-7355 Fax: 86-532-8502-7205 China - Shanghai Tel: 86-21-5407-5533 Fax: 86-21-5407-5066 China - Shenyang Tel: 86-24-2334-2829 Fax: 86-24-2334-2393 China - Shenzhen Tel: 86-755-8203-2660 Fax: 86-755-8203-1760 China - Shunde Tel: 86-757-2839-5507 Fax: 86-757-2839-5571 China - Wuhan Tel: 86-27-5980-5300 Fax: 86-27-5980-5118 China - Xian Tel: 86-29-8833-7250 Fax: 86-29-8833-7256 ASIA/PACIFIC India - Bangalore Tel: 91-80-4182-8400 Fax: 91-80-4182-8422 India - New Delhi Tel: 91-11-4160-8631 Fax: 91-11-4160-8632 India - Pune Tel: 91-20-2566-1512 Fax: 91-20-2566-1513 Japan - Yokohama Tel: 81-45-471- 6166 Fax: 81-45-471-6122 Korea - Gumi Tel: 82-54-473-4301 Fax: 82-54-473-4302 Korea - Seoul Tel: 82-2-554-7200 Fax: 82-2-558-5932 or 82-2-558-5934 Malaysia - Penang Tel: 60-4-646-8870 Fax: 60-4-646-5086 Philippines - Manila Tel: 63-2-634-9065 Fax: 63-2-634-9069 Singapore Tel: 65-6334-8870 Fax: 65-6334-8850 Taiwan - Hsin Chu Tel: 886-3-572-9526 Fax: 886-3-572-6459 Taiwan - Kaohsiung Tel: 886-7-536-4818 Fax: 886-7-536-4803 Taiwan - Taipei Tel: 886-2-2500-6610 Fax: 886-2-2508-0102 Thailand - Bangkok Tel: 66-2-694-1351 Fax: 66-2-694-1350 EUROPE Austria - Wels Tel: 43-7242-2244-39 Fax: 43-7242-2244-393 Denmark - Copenhagen Tel: 45-4450-2828 Fax: 45-4485-2829 France - Paris Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79 Germany - Munich Tel: 49-89-627-144-0 Fax: 49-89-627-144-44 Italy - Milan Tel: 39-0331-742611 Fax: 39-0331-466781 Netherlands - Drunen Tel: 31-416-690399 Fax: 31-416-690340 Spain - Madrid Tel: 34-91-708-08-90 Fax: 34-91-708-08-91 UK - Wokingham Tel: 44-118-921-5869 Fax: 44-118-921-5820 12/08/06 DS22042A-page 26 (c) 2007 Microchip Technology Inc. |
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