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RT9360A/B om c . U White LED Driver (Charge Pump with Current Source) t4 ee General Description h Scompact, high efficient and high FeaturesEfficiency Over 90% of Battery Life The RT9360 isa t apump with current matched white LED Very Highup to 4 WLEDs Support integration charge a Soft Start Function driver. It .D support 1 to 4 White LED's and optimized can Short Circuit Protection for Li-Ion battery applications. The four WLEDs current w Three Charge Pump Mode: X1, X1.5, X2 arew matched for consistent brightness. User can control w on/off via three programming bits. The every 250kHz/1MHz Fixed Frequency Oscillator WLED
WLED channel can support up to 30mA current.
Ordering Information
RT9360A/B
Note :
RichTek Pb-free products are :
-RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. -100%matte tin (Sn) plating.
-Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
For marking information, contact our sales representative directly or through a RichTek distributor located in your area, otherwise visit our website for detail.
Typical Application Circuit
m o .c U t4 e e h S ta a .D w w w
Applications
Package Type QV : QFN-16L 4x4 (V-Type)
Mobile phone White LED Backlighting Camera Flash LED lighting
RoHS Compliant and 100% Lead (Pb)-Free
Operating Temperature Range P : Pb Free with Commercial Standard A : 250kHz B : 1MHz
Pin Configurations
(TOP VIEW)
GND C2P C2N C1N GND 1234
12 11 10 9
LED4 LED3 LED2 LED1
13 14 15 16
8 7 6 5
C1P VIN VOUT ISET
QFN-16L 4x4
C1 1uF
9
C2 1uF
10
+ Li-ion Battery
CIN 1uF
High
RSET
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om .c 4U et he aS at Figure 1. For 4-WLEDs Application Circuit .D w w w
8 11
C1P
7
VIN
C1N C2P C2N 6 VOUT
RT9360A/B
Low
1 EN 2 CTRL0 3 CTRL1 4
CTRL2
5 ISET
GND
LED1 LED2 15 LED3 14 LED4 13
16
12
EN CTRL0 CTRL1 CTRL2
COUT 1uF
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RT9360A/B
C1 1uF
8 9
C2 1uF
11 10
C1P
7
VIN
C1N C2P C2N 6 VOUT RT9360A/B LED1 LED2 15 LED3 14 LED4 13
16
+ Li-ion Battery
CIN 1uF
High Low
1 EN 4 CTRL2 3 CTRL1 2
COUT 1uF
CTRL0
5 ISET
GND
12
RSET
Figure 2. For 3-WLEDs Application Circuit
C1 1uF
8 9
C2 1uF
11 10
C1P
7
VIN
C1N C2P C2N 6 VOUT COUT 1uF
16 15 14 13
+ Li-ion Battery
CIN 1uF
High Low
RT9360A/B 1 EN 4 CTRL2 3 LED1 CTRL1 2 LED2 CTRL0
5 ISET
GND
12
LED3 LED4
RSET
Figure 3. For 2-WLEDs Application Circuit
Functional Pin Description
Pin Number 1 2 3 4 5 6 7 8 9 10 11 12 13 to 16 Pin Name EN CTRL0 CTRL1 CTRL2 ISET VOUT VIN C1P C1N C2N C2P GND Pin Function Chip Enable (Active High). Note that this pin is high impedance. There should be a pull low 100k resistor connected to GND when the control signal is floating. Output Control Bit 0. (See Table 1) Output Control Bit 1. (See Table 1) Output Control Bit 2. (See Table 1) LED current is set by the value of the resistor RSET connected from the ISET pin to ground. Do not short the ISET pin. VISET is typically 1.1V. Output Voltage Source for connection to the LED anodes. Power Input Voltage Positive Terminal of Bucket Capacitor 1 Negative Terminal of Bucket Capacitor 1 Negative Terminal of Bucket Capacitor 2 Positive Terminal of Bucket Capacitor 2 Ground. Exposed pad should be soldered to PCB board and connected to GND.
LED1 to 4 Current Sink for LED. (If not in use, pin should be connected to VOUT)
Exposed Pad GND
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Function Block Diagram
C1N C2P C2N C1P
VIN GND
1x/1.5x/2x 1M/250k Charge Pump
1M/250k Hz Oscillator 1M/250k Selection (Fuse Option) IS
VOUT
Mode Decision
I-Setting
ISET LED1 LED2
EN
Bandgap
VREF
IS
LED3 LED4
CTRL0 CTRL1 CTRL2
Decoder
Table 1
Control Inputs CTRL 2 0 0 0 0 1 1 1 1 CTRL 1 0 0 1 1 0 0 1 1 CTRL 0 0 1 0 1 0 1 0 1 LED 4 OFF OFF OFF ON OFF OFF ON OFF Output Status LED 3 OFF OFF ON OFF OFF ON ON OFF LED 2 OFF ON OFF OFF ON ON ON OFF LED 1 ON OFF OFF OFF ON ON ON OFF
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RT9360A/B
Operation
The RT9360 is a high efficiency charge pump white LED driver. It provides 4 channels low drop-out voltage current source to regulated 4 white LEDs current. For high efficiency, the RT9360 implements x1/x1.5/x2 mode charge pump. An external RSET is used to set the current of white LED. RT9360 has a input current regulation to reduce the input ripple. Soft Start The RT9360 includes a soft start circuit to limit the inrush current at power on and mode switching. Soft start circuit holds the input current level long enough for output capacitor COUT reaching a desired voltage level. When the soft start off, the RT9360 won' t sink spike current from VIN. Mode Decision The RT9360 uses a smart mode decision method to select the working mode for maximum efficiency. Mode decision circuit senses the output and LED voltage for up/down selection. Dimming Control CTRL0, CTRL1 and CTRL2 are used to control the onoff of White LED. When a external PWM signal is connected to the control pin, brightness of white LED is adjusted by the duty cycle. LED Current Setting The current of white LED connected to RT9360 can be set by RSET. Every current flows through the white LED is 440 times greater than the current of RSET. The white LED can be estimated by following equation: Thermal Shutdown The RT9360 provides a high current capability to drive 4 white LEDs. A thermal shutdown circuit is needed to protect the chip from thermal damage. When the chip reaches the shutdown temperature 150C, the thermal shutdown circuit turns off the chip to prevent the thermal accumulation in the chip. Overvoltage Protection The RT9360 regulates the output voltage by controlling the input current. When the output voltage reaches the designated level, the RT9360 reduces the input current. And then, the output voltage regulation also serves an overvoltage protection. Short Circuit Protection A current limiting circuit is also included in the RT9360 for short circuit protection. Whenever output source a dangerously high current, the current limiting circuit takes over the output regulation circuit and reduces the output current at an acceptable level.
V ILED = 440 x ( ISET ) R SET
where VISET = 1.1V, and RSET is the resistance connected from ISET to GND.
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Absolute Maximum Ratings
(Note 1) Input Voltage ------------------------------------------------------------------------------------------------------------- -0.3 to 6V Output Voltage ----------------------------------------------------------------------------------------------------------- -0.3 to 6V Power Dissipation, PD @ TA = 25C QFN-16L 4X4 ------------------------------------------------------------------------------------------------------------ 2.5W Package Thermal Resistance (Note 4) QFN-16L 4x4, JA ------------------------------------------------------------------------------------------------------- 40C/W Junction Temperature -------------------------------------------------------------------------------------------------- 150C Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260C Junction Temperature Range ---------------------------------------------------------------------------------------- -40C to 125C Storage Temperature Range ----------------------------------------------------------------------------------------- -65C to 150C ESD Susceptibility (Note 2) HBM (Human Body Mode) ------------------------------------------------------------------------------------------- 2kV MM (Machine Mode) --------------------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions Electrical Characteristics
(Note 3)
Ambient Temperature Range ---------------------------------------------------------------------------------------- -40C to 85C
(VIN = 2.85V to 5.5V, C1 = C2 = 1.0F (ESR = 0.03, TA = 25C, unless otherwise specified)
Parameter Input Supply Voltage Undervoltage Lockout Threshold Undervoltage Lockout Hysteresis
Symbol VIN VIN rising
Test Conditions
Min 2.5 1.8 --
Typ
Max 5.5
Units V V mV mA mA mA mA mA mA uA % % V V kHz MHz mA V
2.2 50 20 5 --1.5 3 1 2 1 3.75 2.85 250 1.0 400 5.5
2.4 -21.5 5.5 20 30 2.0 4 10 7.5 5 3.85 2.95 300 1.2 650 6
RSET = 24k Current into LEDs 1, 2, 3 and 4 ILED RSET = 91k 2.7V < VIN < 5.5V 3.1V < VIN < 5.5V RT9360A Quiescent Current RT9360B RT9360A/B ILED Accuracy (Note 5) Current Matching (Note 6) 1x mode to 1.5x mode Transition Voltage (VIN falling) 1.5x mode to 2x mode Transition Voltage (VIN falling) Oscillator Frequency Input Current Limit Output Over Voltage Protection ILED-ERR IQ FOSC=250KHz, EN = High, No Load FOSC=1MHz, EN = High, No Load VIN = 4.2V, EN = Low 2mA < ILED < 30mA
18.5 4.5 2 2 -------200 0.8 250 --
ILED-LED-ERR 2mA < ILED < 30mA VLED= 3.5V, IOUT= 80mA ILED1 = ILED2 = ILED3 = ILED4 = 20mA VLED= 3.5V, IOUT= 80mA VTRANS1.5X ILED1 = ILED2 = ILED3 = ILED4 = 20mA RT9360A FOSC RT9360B VTRANS1X ILIMIT VOVP Short Circuit applied from VOUT to GND Open circuit at any LED that is programmed to be in the on state
To be continued
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RT9360A/B
Parameter Input High Threshold Input Low Threshold Input High Current Input Low Current Thermal Shutdown Threshold Thermal Shutdown Hysteresis Symbol VIH VIL IIH IIL Test Conditions Input high logic threshold (EN, CTRL0, CTRL1, CTRL2) Input low logic threshold (EN, CTRL0, CTRL1, CTRL2) VIH = VIN VIL = GND Min 1.5 ---140 -Typ ----150 10 Max -0.4 1 1 180 -Units V V uA uA C C
Note 1. Stresses listed as the above "Absolute Maximum Ratings" may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. Note 2. Devices are ESD sensitive. Handling precaution recommended. Note 3. The device is not guaranteed to function outside its operating conditions. Note 4. JA is measured in the natural convection at T A = 25C on a low effective thermal conductivity test board of JEDEC 51-3 thermal measurement standard. Note 5. ILED(ERR) = ILED(MEA) - ILED(SET) ILED(SET) x 100%
Note 6. Current Matching refers to the difference in current from on LED to the next. ILED Current Matching = ILED(MAX) - ILED(MIN) ILED(MAX) + ILED(MIN) x 100%
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Typical Operating Characteristics
LED Current vs. Input Voltage
24 23
X1 to X1.5 Mode Transition Voltage vs. LED Current
4.4
Mode Transistion Voltage (V)
RSET = 24k TA = 25C
VF is defined at ILED = 20mA
4.2 4 3.8 3.6 3.4 3.2 3
VF = 3.6V
LED Current (mA)
22 21 20 19 18 17 16 2.5 3 3.5 4 4.5 5 5.5
VF = 3.4V
VF = 3.2V
5
10
15
20
25
30
Input Voltage (V)
LED Current (mA)
Input Voltage vs. Quiescent Current
4 3.5
Logic Threshold Voltage vs. Input Voltage
1.4
RSET = 24k TA = 25C X1.5 Mode 1MHz
Quiescent Current (mA)
1.3
3 2.5 2 1.5 1 2.5 3 3.5
Threshold Voltage (V)
VIH
1.2 1.1 1 0.9 0.8
VIL
X1 Mode 250kHz
4
4.5
5
5.5
2.5
3
3.5
4
4.5
5
5.5
Input Voltage (V)
Input Voltage (V)
Efficiency (LED) vs. Input Voltage
90 85 80
Efficiency (LED) vs. Input Voltage
90 85 80
Efficiency (%)
70 65 60 55 50 4.3 4.2 4.1 4 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.2 3.1
Efficiency
f = 1MHz, VF = 3.3V IOUT = 80mA
75
75 70 65 60 55 50 4.3 4.2 4.1 4.0 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.2 3.1
f = 1MHz, VF = 3.3V IOUT = 60mA
Input Voltage (V)
Input Voltage (V)
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RT9360A/B
Efficiency (Converter) vs. Input Voltage
95 94 93
96 95 94
Efficiency (Converter) vs. Input Voltage
Efficiency (%)
92 91 90 89 88 4.3 4.1 3.9 3.7 3.5 3.3 3.1
Efficiency (%)
f = 1MHz, VF = 3.3V IOUT = 80mA
93 92 91 90 89 88 4.3 4.1 3.9 3.7 3.5 3.3 3.1
f = 1MHz, VF = 3.3V IOUT = 60mA
Input Voltage (V)
Input Voltage (V)
LED Current vs. Input Voltage
25 24 23
2.3
UVLO Voltage vs. Temperature
RSET = 24k
2.2
LED Current (mA)
22 21 20 19 18 17 16 15 2.5 3 3.5 4
TA = -40C
2.1
VIN (V)
POR
2
TA = 85C
POF
1.9 1.8 1.7
4.5
5
5.5
-40
-25
-10
5
20
35
50
65
80
95
Input Voltage (V)
Temperature (C)
Inrush Current Response
VIN
(2V/Div)
Inrush Current Response
VIN
(2V/Div)
(2V/Div)
EN
(2V/Div)
C1P
EN
(5V/Div)
C1P
(5V/Div)
IIN
(200mA/Div)
IIN
VIN = 3.0V (200mA/Div) VIN = 4.3V
Time (100s/Div)
Time (100s/Div)
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Mode Change Inrush Current (X1 to X1.5)
VIN C1P
(2V/Div) (2V/Div) (2V/Div)
Normal Operation
VOUT VIN
(1V/Div)
C2P
(2V/Div)
C1P
(1V/Div)
ILED
(10mA/Div)
I IN
(100mA/Div) VIN = 2.5V, ILED= 20mA
Time (40s/Div)
Time (2s/Div)
Normal Operation
VIN C1P VOUT
(2V/Div) (2V/Div) (2V/Div)
Normal Operation
VIN
(2V/Div)
C1P
(2V/Div)
C1N
(2V/Div)
ILED
(10mA/Div)
ILED
(10mA/Div)
VIN = 3.2V, ILED= 20mA
VIN = 4.3V, ILED= 20mA
Time (2s/Div)
Time (2s/Div)
Dimming Operation
Dimming Operation
C2P C2P
(2V/Div) (2V/Div) (2V/Div) (2V/Div)
C1P VOUT
(2V/Div)
C1P VOUT
(2V/Div)
ILED
(10mA/Div) VIN = 3.0V, CTRL 0 Duty = 20%
ILED
(10mA/Div) VIN = 3.0V, CTRL 0 Duty = 80%
Time (400s/Div)
Time (400s/Div)
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RT9360A/B
Dimming Operation
VOUT
(2V/Div)
Dimming Operation
VOUT
(2V/Div)
C1P
(2V/Div)
C1P
(2V/Div)
C2P
(2V/Div)
C2P
(2V/Div)
ILED
(10mA/Div) VIN = 4.3V, CTRL 0 Duty = 20%
ILED
(10mA/Div) VIN = 4.3V, CTRL 0 Duty = 80%
Time (400s/Div)
Time (400s/Div)
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Applications Information
Selecting Capacitors To get the better performance of RT9360, the selecting of peripherally appropriate capacitor and value is very important. These capacitors determine some parameters such as input and output ripple, power efficiency, maximum supply current by charge pump, and start-up time. To reduce the input and output ripple effectively, the low ESR ceramic capacitors are recommended. Generally, to reduce the output ripple, increasing the output capacitance COUT is necessary. However, this will increase the start-up time of output voltage. For LED driver applications, the input voltage ripple is more important than output ripple. Input ripple is controlled by input capacitor CIN, increasing the value of input capacitance can further reduce the ripple. Practically, the input voltage ripple depends on the power supply's impedance. If a single input capacitor CIN cannot satisfy the requirement of application, it is necessary to add a low-pass filter. Figure 1 shows a C-R-C filter used on RT9360A. The input ripple can be reduced less than 30mVp-p when driving 80mA output current. Setting the LED Current The RT9360 can be set a fixed LEDs current by a resister RSET connected from ISET to GND. RSET establishes the reference current and mirrors the current into LED1, LED2, LED3, and LED4. The current into LED is about 440 times of the current flows through the RSET, the approximate setting formula is given as follows:
ILED =
484(V) R SET ()
(1)
Figure 2 shows the typical value of RSET versus average LED current and Table 1 shows the values of RSET for a fixed LED current.
250
200
150
100
RT9360A VIN 2.2uF 1 VIN 2.2uF
50
0 0 5 10 15 20 25 30
Figure 1. C-R-C filter used to reduce input ripple The flying capacitor C1 and C2 determine the supply current capability of the charge pump and to influence the overall efficiency of system. The lower value will improve efficiency, but it will limit the LED's current at low input voltage. For 4 X 20mA load over the entire input range of 2.7 to 5.5V, a capacitor of 1F is optimal.
Figure 2. The typical curve of RSET vs. LED's average current. Table 1. RSET Value Selection
ILED (mA) 5 10 15 20 25 30 RSET (k) 91.0 47.9 32.7 24.0 19.6 16.4 Nearest Standard Values for RSET (k) 91.0 47.5 32.4 24.0 19.6 16.5
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RT9360A/B
If maximum accuracy is required, a precision resister is needed. Equation (2) shows how to calculate the error ILED(ERR). ILED(ERR) = ILED(MEA) - ILED(SET) x 100% ILED(SET) (2) LED Dimming Control Methods The RT9360 can use two methods to achieve the LED dimming control. These methods are detailed described as following:
(1). Dimming using PWM signal into CTRL0, CTRL1, and CTRL2
Where ILED(MEA) is practical LED current ILED(SET) is LED current which is determined by the RSET. LED current setting with NMOS LED current setting control can also be achieved by used the external NMOS to change equivalent resister of ISET pin. Figure 3 shows this application circuit of method. For this example, a 3 bit signals can set 8 kinds of different equivalent resister of ISET pin, i.e. produce 8 kinds of LED current level. Table 2 shows the relation between equivalent resister of ISET pin and control signal.
RT9360A/B ISET R4 R2 S2 S1 R1
LED current can be controlled by applying a PWM signal to CTRL0, CTRL1, or CTRL2. Table3 shows the relation between CTRLx and 4 LED's current states. For an example, as the CTRL1 and CTRL2 are pulled logical high and CTRL0 receives a PWM signal, then, four LEDs will be dimmed synchronously. Here, the PWM signal setting the LED's current ON/OFF can achieve the average LED's current which in design. The application circuit is shown in Figure 4. Figure 5, and Figure 6 show 3WEDs and 2WLEDs PWM dimming application circuit, respectively. During the time of PWM signal logical low, the current is a fixed value and setting by RSET resistor. So the average LEDs current can be approximated as Equation (3).
ILED(AVG) =
Where:
TOFF x ILED(ON) TPWM
(3)
R3
TPWM is the period of PWM dimming signal
S3
TOFF is the time of PWM signal at low. ILED(ON) is LED on state current.
Figure 3. The application circuit of setting LED current which using a NMOS to set RSET. Table 2. The relation between control signal and equivalent resister of ISET pin
S1 0 0 0 0 1 1 1 1 S2 0 0 1 1 0 0 1 1 S3 0 1 0 1 0 1 0 1 Equivalent Resister of ISET pin (RSET) RSET = R4 RSET = R3//R4 RSET = R2//R4 RSET = R2//R3//R4 RSET = R1//R4 RSET = R1//R3//R4 RSET = R1//R2//R4 RSET = R1//R2//R3//R4
Table 3. The relation between CTRLx and 4 LED's's current states
Control Inputs CTRL0 CTRL1 CTRL2 LED1 0 1 0 1 0 1 0 1 0 0 1 1 0 0 1 1 0 0 0 0 1 1 1 1 ON OFF OFF OFF ON ON ON OFF Output Status LED2 LED3 LED4 OFF ON OFF OFF ON ON ON OFF OFF OFF ON OFF OFF ON ON OFF OFF OFF OFF ON OFF OFF ON OFF
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VIN RT9360A/B CTRL2 CTRL1 CTRL0 EN PWM
Table 4. The common dimming frequency and its corresponding maximum duty.
Dimming
LED LED OFF ON
CTRLX Maximum Duty 0.90 0.91 0.92 0.93 0.94 0.95 0.96 0.97 0.98
ILED Minimum Duty 0.10 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02
Frequency (Hz) 1K 900
Figure 4. The PWM dimming application circuit for 4WLEDs
VIN RT9360A/B CTRL2 CTRL1 CTRL0 EN PWM LED LED OFF ON
800 700 600 500 400 300 200
Figure 5. The PWM dimming application circuit for 3WLEDs
VIN RT9360A/B CTRL2 CTRL1 CTRL0 EN PWM LED LED OFF ON
(2). The PWM dimming by GPIO
The PWM dimming by GPIO is shown as Figure 7. DZ shall be a Schottky diode with forward voltage less than 0.3V at IF = 1mA. C3 is a capacitor to keep the enable pin voltage is higher than the threshold voltage. R1 is discharge resister and it should be not too high to prevent the off time too long while turned-off. The recommended conditions are shown as following. 1. The recommended value for R1 and C3 are 200k (5%) and 0.22uF (X7R, 10%). 2. The forward voltage of the Schottky diode shall be less than 0.3V at 1mA. 3. The output voltage of GPIO should be greater than 2.8V and keep the voltage on EN pin is higher than 1.5V. 4. The PWM frequency should be in the range of 500Hz~1.5kHz or 20kHz~30kHz for audio noise consideration. 5. The PWM duty cycle shall be in the range of 30% to 95%. 6. The driving capability of the GPIO should be greater than 2mA @ 2.8V. 7. The LED current can be obtained by the equation, VISET ILED = 440 x x (1 - DPWM ) R SET (The typical value of VISET is 1.1V)
Figure 6. The PWM dimming application circuit for 2WLEDs Besides, RT9360 has 100us delay time between mode transfer. This delay time makes different dimming frequency corresponds to different maximum duty of CTRLX pin. When the duty cycle of dimming frequency excess maximum duty, the RT9360s can' t transfer the mode normally. Equation (4) shows the relation between maximum duty of CTRLX pin and PWM dimming frequency. Table 4 is shown the common dimming frequency and its corresponding maximum duty. For better performance consideration, the maximum PWM dimming frequency is recommended below 1kHz.
DMAX = (1 - 100 x 10 -6 x FD)
Where : DMAX is Maximum Duty of CTRLX FD is PWM Dimming Frequency
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(4)
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RT9360A/B
PWM Signal VEN>1.5V VDD 2.8V GPIO DZ C3 RT9360A/B R SET ISET CTRL2 CTRL1 CTRL0 EN VIN
PCB Board Layout The RT9360 is a high-frequency switched-capacitor converter. For best performance, place all of the components as close to IC as possible. Besides a solid ground plane is recommended on the bottom layer of the PCB. The ground should be connected CIN and COUT together and as close to the IC as possible. Figure 9 shows the typical layout of RT9360' s EVB board.
R1
Figure 7. The GPIO PWM dimming application circuit
20 18 16
LED Current (mA)
14 12 10 8 6 4 2 0 30 40 50 60 70 80 90 100
Top Layer
GPIO PWM Duty (%)
Figure 8. GPIO PWM dimming duty v.s. ILED current (RSET = 19k)
Bottom Layer Figure 9. The typical layout of RT9360' s EVB board
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Outline Dimension
D2 L 1 E E2
D
e A A3 A1
b
Symbol A A1 A3 b D D2 E E2 e L
Dimensions In Millimeters Min 0.800 0.000 0.175 0.250 3.950 2.150 3.950 2.150 0.650 0.500 0.600 Max 1.000 0.050 0.228 0.350 4.050 2.350 4.050 2.350
Dimensions In Inches Min 0.031 0.000 0.007 0.010 0.156 0.085 0.156 0.085 0.026 0.020 0.024 Max 0.039 0.002 0.009 0.014 0.159 0.093 0.159 0.093
V-Type 16L QFN 4x4 Package
RICHTEK TECHNOLOGY CORP.
Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611
RICHTEK TECHNOLOGY CORP.
Taipei Office (Marketing) 8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com
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