® QPO-1-EVAL1 QuietPower ™ QPO Evaluation Board Description Features QPO-1 The QPO-1-EVAL1 kit is designed to allow full testing of the QPO-1 and the various performance options to optimize a final system design. The board offers two terminal options for vertical or horizontal mounting. The user must select the required values for the Rhr, Rsc and Rsa resistors and solder them in the designated positions before applying power to the EVAL1. Please refer to the QPO-1 product data sheet, schematics and the following pages for the proper application of this board. • >30 dB PARD attenuation, 1 kHz to 500 kHz The QPO-1 output ripple attenuator SiP uses active filtering to reduce output ripple and noise (PARD) over 20 dB from 500 Hz to 500 kHz and can be extended down to 50 Hz with additional capacitance added to the VREF pin. The QPO-1 operates over a voltage range from 3 to 30 Vdc 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 quiet point-of-load regulation when used in conjunction with the power supply’s control loop or trim node. • LGA mounting Typical Application QPO-1 Performance LOAD+ VOUT+ QPO IN • 10A rating • Supports precise point-of load regulation • 90-99% efficiency • User selectable performance optimization for Attenuation, power dissipation, transient response • 1.0 x 1.0 x 0.2" SiP • Closed control loop improves transient response of most DC-DC converters and power supplies • Reduces required number of output capacitors to support dynamic loads. • Evaluation board includes Johnson Jack for lownoise measurement of QPO performance. QPO IN (AC) QPO OUT Rsc SENSE+ QPO-1 SC • 3-30 Vdc operating range SC Cout SC SET CESR REFGND GND QPO OUT (AC) VREF SENSE- Rhr VOUTLOAD- Figure 1 – SC/Trim supports applications that don’t require remote sense. Picor Corporation • www.picorpower.com LOAD CURRENT (DC) 5A/DIV Figure 2 – Typical performance with a 3.3 Volt converter, showing 1 to 10 A load step. QPO-1-EVAL1 Data Sheet Rev. 1.2 Page 1 of 4 PC Board Layout Diagram QPO-1 EVAL BOARD LGA RSA R1 RHR J9 XXXXA CESR J10 AVXXX CHR RSC PHIL RSCSET CP US AND FOREIGN PATENTS, PATENTS PENDING RP J12 J11 Q1 π π PICOR QPO-1 DZ1 CSU RSU RSENSE C1 R2 J1 J2 J3 J4 J5 J6 J7 J8 Mounting Options Vertical Mount 1.800 R1 RHR RSA XXXXA CESR QPO-1 EVAL BOARD LGA J10 AVXXX J9 CHR 0.442 RSC PHIL RSCSET US AND FOREIGN PATENTS, PATENTS PENDING RP π PICOR π QPO-1 J12 RSU CP DZ1 CSU J11 1.600 RSENSE C1 Q1 R2 J1 J2 J3 J4 J5 J6 J7 J8 Horizontal Mount 0.542 Picor Corporation • www.picorpower.com QPO-1-EVAL1 Data Sheet Rev. 1.2 Page 2 of 4 Board Circuit Schematic J11 JOHNSONJACK (NOT STUFFED) J6 QPO_IN J2 QPO_OUT QPO_IN C1 15uF J8 SENSE+ CESR 5 REFGND 6 RSCSET CESR 15uF QPO-1 QPO OUT QPO IN J4 GND J9 GND J10 GND RSENSE 51.1 10 9 8 7 SC SET 4 20 CP VREF Start-up Assist Circuit 19 GND QPO OUT QPO OUT QPO OUT QPO OUT 3 J5 SC 15 PEAK IN 16 SC RSC GND To J1 VREF QPO IN QPO IN QPO IN QPO IN 2 CSU 1uF 11 12 13 14 RP 1K Q1 IRLML5103 SLOPE ADJ RSU 2K 17 18 J3 QPO_OUT GND DZ1 18V J7 QPO_IN 1 QPO_IN R2 100 J12 JOHNSONJACK QPO_OUT RSA J1 VREF Remote Sense Circuit RHR CHR R1 0 Ohm Instructions for Use The EVAL1 board has the following components, QPO-1, Cesr=15uF and Rp=1k Ohm already soldered to the PCB as well as the zero-headroom start-up assist circuit shown in the schematic above. The remaining pads are spaced for 1206 chip size components. If these are not available to the user, once values are determined axial component leads can be formed to line up with the pads and hand soldered to the proper pads. Refer to the schematic and mechanical drawing above for the pad locations to connect these components. Component values can be determined using the formulas below. Refer to the QPO-1 product data sheet for a complete explanation of the features and the parameters set by these component values. First determine the headroom resistor value. Rhr = QPOout * 2.5kΩ Vhr where; Rhr = headroom setting resistor value, QPOout = the expected voltage on the QPO’s output, Vhr = the target headroom voltage determined from the product data sheet. Picor Corporation • www.picorpower.com 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: RSC = RIN * VOUT VRPT where; RSC is the SC SET resistor value, RIN is the 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 or TRIM. IMPORTANT NOTE: When connecting the Rsc resistor into the EVAL1 board note the pad landing for the Rsc resistor that is adjacent to the VIA hole that also connects to CESR’s lower pad. The resistor must be connected/soldered to that VIA hole point to make proper connection to the circuit and not just to the resistor pad landing. QPO-1-EVAL1 Data Sheet Rev. 1.2 Page 3 of 4 The peak detector function is enabled on the evaluation board. Connecting a 0.1uF capacitor to the CP pads disables the peak detector if not desired for the application. 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 to cause the converter’s output to increase to the point where an over-voltage fault is created and the converter will shut down. Check the converter’s OVP set point and select component values to keep the QPO headroom adjustment from reaching the OVP trip point. The slope adjust feature can be set to zero providing relatively constant headroom versus load using an Rsa of 100kΩ. To improve efficiency of the filter the slope adjust feature can provide a specific reduction in headroom (slope adjust) over a desired current range. The user can optimize performance based on the expected variation in load current and the desired power dissipation range. The formula below should be used to calculate the Rsa value for the desired headroom slope versus current. If the peak detector is enabled, the peak of the ripple will be added back to the headroom at a given load condition. RSA = 0.05(V/A) * Typical standard 1% values for the Rhr and Rsc resistors and the listed voltages QPOout Voltage Headroom Voltage Rhr Value Rsc Value1 3.3V 375mV 22k 2.67k 5.0V 375mV 33.2k 4.02k 12.0V 375mV 80.6k 9.76k 15.0V 375mV 100k 12.1k 24.0V 375mV 160k 19.6k 28.0V 375mV 187k 22.6k Note1: These Rsc values are for a converter with a 1.23 Volt pre-trimmed reference and 1k Ohm input resistance on the SC/Trim. Typical Value For Rsa Resistor and Typical Voltages QPOout Voltage Headroom Voltage Change (Slope=∆V) Rsa Value Load Current Change 3.3V 150mV 8.25k 10 A 5.0V 150mV 8.25k 10 A 12.0V 150mV 8.25k 10 A 15.0V 150mV 8.25k 10 A 24.0V 150mV 8.25k 10 A 28.0V 150mV 8.25k 10 A ∆ Iout * 2.5kΩ ∆Vhr where: ∆Iout = Maximum load current change ∆Vhr= Change in headroom desired over the load range Rsa= Slope adjust resistor value Ordering Information Part Number Description QPO-1 EVAL1 Evaluation board for QPO-1 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 Picor Corporation • www.picorpower.com • QPO-1-EVAL1 Data Sheet Email Vicor Express: [email protected] Technical Support: [email protected] P/N 26801 Rev. 1.2 7/04/10M