View QPO-1-EVAL5_1299992.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

P R E L I M I N A RY
QuietPower TM
QPO-1-EVAL5
QPO-1 Evaluation Board, Mini Foot Print DC-DC Converters
Description
The QPO-1-EVAL5 is designed to allow full testing of the QPO-1 and its various performance settings to optimize final system design. The board offers switch settings for the user to select preset values for the Rhr, Rsc, and Rsa resistors. Solder pads are available to mount user-selected values of these components if required. Please refer to the QPO-1 product data sheet and the following pages for the proper application of this board. The EVAL5 accommodates Vicor's Mini DC-DC converters with an input up to 72 Vdc. The QPO-1 output ripple attenuator SiP uses active filtering to reduce output ripple and noise (PARD) over 20 dB from 50 Hz to 500 kHz. The QPO-1 operates over a voltage range from 3 to 30Vdc and supports load currents as high as 10A. Output regulation is maintained with remote sense or trim adjustment of the power supply. The closed loop architecture improves transient response and ensures precise point-of-load regulation. Other eval boards (see www.picorpower.com) allow easy evaluation with other DC-DC converters or power supplies with standard terminations.
Features of the QPO-1
* >30 dB PARD attenuation, 1 kHz to 500 kHz * >20 dB PARD attenuation, 50 Hz to 500 Hz 1 * 10A rating over a 3-30 Vdc operating range * Supports precise point-of load regulation * Up to 99% efficiency with power limit protection * User selectable optimization of attenuation, power dissipation & transient load response * Peak detector function optimizes for ripple amplitude variation automatically * 1.0 x 1.0 x 0.2" SiP with BGA or LGA mounting * Improves transient response of most DC-DC converters and power supplies * Reduces required number of output capacitors to support dynamic loads. * Patents Pending
Note 1: For off-line supplies 20dB attenuation can be achieved down to 50Hz with additional capacitance added from the VREF pin to the REFGND pin.
Typical Application
QPO-1 Performance
LOAD+ VOUT+ SENSE+ QPO-1 SC
SC REFGND SC SET CESR VREF QPO IN QPO OUT
QPO IN (AC)
Rsc Cout
GND
QPO OUT (AC)
Rhr
SENSEVOUT-
LOAD-
LOAD CURRENT (DC) 1A/DIV
Figure 1 - SC/Trim supports applications without the use of remote sense. Picor Corporation * www.picorpower.com
Figure 2 - Typical performance with a 3.3 Volt converter. QPO-1-EVAL5 Data Sheet Rev. 1.1 Page 1 of 4
P R E L I M I N A RY
PICOR QPO-1
3V to 30V Input
Mini Application Board rev.2
Load+ C8 C9 QPO IN
Optional Transient Capacitors
QPO OUT
LOAD+ LOAD+
10A Maximum
1
9
2
8
7
SW1
3
6
Input Supply
Remote Sense
4
-
5
SC
EARTH/Baseplate
Figure 3 - EVAL5 layout and measurement locations
QPO IN Q1 IRLML6401 Low Voltage Start-up Circuit Shorted when SW1 in SC mode QPO IN SENSE+
C1 4.7nF
BasePlate
C2 4.7nF
QPO OUT D1 12V
18
17
3
6
3 2 1 Input Supply
VIN-
4 3 SC 2
SW1 5 6 7
Remote Sense GND SC SC 2 1 SW2A 4 204-2ST C7 TBD
11 12 13 14 15 16 19
QPO OUT
QPO IN
4
5
SLOPE ADJ
REFGND
C5 100uF 2
MINI FOOTPRINT
7
VIN+ 1 9
1 8 204-221ST SENSE+ 3 QPO IN
SW2B 204-2ST C11 TBD C6 R12 22uF 5.1 QPO OUT
VREF
8
GND
GND
20
1
2
3
4
3
2
C3 4.7nF
SW4 CAS-120B1 VREF C10 15uF QPO OUT
BasePlate
C4 4.7nF
C8 C9 270uF 270uF
1
R6 86.6K 12 11
R7 9.76K
R8 35.7K 10 9
R9 4.02K
R10 23.7K 8 7
R11 2.67K
SW3A 204-213ST 1 2
SW3B 204-213ST 3 4
SW3C 204-213ST 5 6
VREF 12V 5V 3.3V
Resistor's based on 350mV headroom at all voltages.
Figure 4 - Schematic of EVAL5 board
Picor Corporation * www.picorpower.com
12
SW2
C11 VREF
12V 5V 3.3V User Defined = All Off
SC SET
O N
Supply+ SupplyEarth
+
1
+
C5
C6
Q1 D1 R12
QPO-1
R1
ENGINEERING SAMPLE
US AND FOREIGN PATENTS, PATENTS PENDING
LOADLOADR2
PHIL
C7
LoadGND
QPO-1
XXXXA
COUT R5
SC
QPO-1
R4
R6 R7 R8 R9 R10 R11
SC ON SC CAP
SW4
C10
SW3 O N
1
2
3
Slope Adjust Enable
QPO IN QPO IN
QPO OUT QPO OUT QPO OUT Load+ 2 1 R2 User Defined
QPO OUT QPO OUT QPO OUT QPO OUT SC SET CESR
R1 TBD
QPO IN QPO IN QPO IN QPO IN PEAK IN SC GND
10 9 8 7 6 5 CESR COUT 15uF LoadGND 2 1 SC SET
QPO-1
R4 TBD R5 User Defined
VREF
QPO-1-EVAL5 Data Sheet Rev. 1.1 Page 2 of 4
P R E L I M I N A RY
Switch Tables
The QPO-1-EVAL5 board has been designed to accommodate a wide range of output voltages from a Vicor Mini DC-DC converter. Please refer to the QPO-1 datasheet for description of the product. SW1 is used to select the method of regulating the output voltage of the converter. When switched to the left, the converter is operating in "Remote Sense" mode where the sense pins of the converter monitor the point of load to regulate the converter's output voltage. When switched to the right, the converter's sense pins are tied directly to their respective output pins. The QPO trims the SC pin of the converter to compensate for its voltage drop. If the SC mode is selected SW2 should be set to have the SC function connected to the converter as described below. SW2 has two switches. One engages the SC control function. The second adds a capacitor to the SC pin of the converter. In the "on" position (right), the first switch of SW2 connects a 3.3uF capacitor (C11) between the SC pin of the converter and ground. C11 extends the soft start time of the converter. This capacitor should only be needed with low voltage converters (<12V) that startup before the QPO can establish proper operation. The second switch of SW2 in the "on" position (right) connects the SC control circuit of the QPO to the SC pin of the converter. When the switches are in the "off" (left) position, the capacitor and SC connection are opened and out of the circuit. SW3 is located in the lower-right corner of the pc board. It is used to set the appropriate headroom voltage and SC current for converters 12V, 5V, or 3.3V outputs. A "user defined" position for converter voltage and headroom settings is provided to support other output voltages. The user can also adjust other operating parameters with the "user defined" position With all switches in the "down" position (open circuit), the board is set to a "user defined" setting for use with any output voltage between 3 and 30V. The QPO-1-EVAL5 board lets the user populate the R2 and R5 locations to adjust headroom (Rhr) and SC current, (Rsc) with appropriate resistors. The user must calculate a value for the headroom voltage setting resistor (R5 = Rhr in the product datasheet and formula below) and the SC current setting resistor (R2 = Rsc in the product datasheet and formula below). With the first switch position of SW3 in the "up" position, and the rest in the "down" position, the headroom voltage and SC current setting is adjusted to work with a 12V converter. With the second switch of SW3 in the "up" position, the rest "down", the converter is set to work with a 5V converter. With the third switch "up", the rest "down", the board is set to work with a 3.3V converter. This switching network will parallel the switched in resistors with connections to the R5 and R2 positions. If a predefined voltage is to be used, R5 and R2 should not be populated. At no time should more than one switch be in the "up" position to get accurate results. The user defined values for R2 and R5 will have to be connected once their values have been determined using the formulas that follow. SW4 is used to engage the optional Slope Adjust resistor (R4) when in the "up" position. Please refer to the QPO-1 datasheet for further explanation of this function.
Instructions for Use
The terminal block in the lower left-hand corner of the pc board (labeled "Input Supply") is used to provide the input voltage to the DC-DC converter. The Earth connection serves as the converter shield that is the common node for the Y capacitors that are on the bottom of the board. The converter should be mounted to the EVAL board with screws and a heat sink to ensure a good electrical connection to the bypass capacitors on the bottom of the board. If this step is no taken, common mode noise may be excessive. The output load should be connected to the terminal block on the right, labeled "External Load" and should not exceed 10 Amps. The QPO application board has Johnson Jacks, to reduce the effect of radiated noise on measurements. The jacks allow three key measurements; QPO IN is the input to the QPO from the DC-DC converter; QPO OUT is the output of the QPO where effects of the various settings can be analyzed; VREF is the reference voltage that the QPO uses to maintain a desired output voltage.
Picor Corporation * www.picorpower.com
QPO-1-EVAL5 Data Sheet Rev. 1.1 Page 3 of 4
If SW3 is not used as described above, a resistor in position R5 will determine the QPO's headroom voltage. If the user decides to use a headroom setting other than what is preset by SW3, select a headroom resistor for R5 using the following equation:
Rhr =
QPOout * 2.5k Vhr
or TRIM. On the application board there are two spots for additional capacitors (C8 and C9) to be added to the QPO's input. Extra output capacitors maybe required in applications with converters with output voltages over 10V that are subjected to high transient load steps. Experiment with these components to obtain the desired result. The peak detector function is enabled on the evaluation board. A low value for R1 (less than 10 ohms) is on the board and C7 is not populated. To disable the peak detector function, use R1= 1K and C7 = .1uF as shown in the datasheet. The QPO's peak detector circuit will increase the headroom of the QPO by roughly half of the peak-to-peak ripple on the QPO's input. Excessive ripple with low voltage converters could create enough additional headroom as to cause the converter's output to increase to the point where it is in an over-voltage fault and shut down.
where; Rhr is headroom resistor value, QPOout is the voltage seen on the QPO's output, Vhr is the target headroom voltage.
The Rsc resistor is tied between QPOOUT and SC SET pin and sets the correction current used to trim up the converter to maintain a constant output voltage on the QPO's output. The value for the SC SET resistor is calculated by the following equation:
Ordering Information
Part Number QPO-1-EVAL5 Description Evaluation board for QPO-1 for Mini footprint DC-DC Converters
Rsc =
Rin * Vout Vrpt
where; Rsc is SC SET resistor value, Rin is the input resistance of the SC or TRIM input of the converter, Vout is the desired QPO output voltage, Vrpt is the pre-trimmed reference of the SC
Vicor's comprehensive line of power solutions includes high-density AC-DC & DC-DC modules and accessory components, fully configurable AC-DC & DC-DC power supplies, and complete custom power systems.
Information furnished by Vicor is believed to be accurate and reliable. However, no responsibility is assumed by Vicor for its use. No license is granted by implication or otherwise under any patent or patent rights of Vicor. Vicor components are not designed to be used in applications, such as life support systems, wherein a failure or malfunction could result in injury or death. All sales are subject to Vicor's Terms and Conditions of Sale, which are available upon request.
Specifications are subject to change without notice.
Vicor Corporation 25 Frontage Road, Andover, MA, USA 01810 Tel: 800-735-6200 Fax: 978-475-6715
Email Vicor Express: vicorexp@vicr.com Technical Support: apps@vicr.com
Picor Corporation * www.picorpower.com * QPO-1-EVAL5 Data Sheet
P/N 27092
Rev. 1.1
8/03/10M

▲Up To Search▲

Price & Availability of QPO-1-EVAL5

	To Download QPO-1-EVAL5 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .