View SP6132EB_36133.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

SP6132 Evaluation Board Manual
Easy Evaluation for the SP6132 12V Input, 0 to 10A Output Synchronous Buck Converter Precision 0.80V with 1% High Accuracy Reference. UVIN and Output Dead Short Circuit Shutdown Protection Features. High Efficiency: 94% Feature Rich: UVIN, Programmable Softstart, External VCC Supply and Output Dead Short Circuit Shutdown Protection.
SP6132EB SCHEMATIC
Rev 09/15/03
SP6132 Evaluation Manual
Copyright 2003 Sipex Corporation
USING THE EVALUATION BOARD 1) Powering Up the SP6132 Circuit Connect the SP6132 Evaluation Board with an external +12V power supply. Connect with short leads and large diameter wire directly to the "VIN" and "GND" posts. Connect a Load between the VOUT and GND posts, again using short leads with large diameter wire to minimize inductance and voltage drops. 2) Measuring Output Load Characteristics It's best to GND reference scope and digital meters using the Star GND post in the center of the board. VOUT ripple can best be seen touching probe tip to the pad for COUT and scope GND collar touching Star GND post - avoid a GND lead on the scope which will increase noise pickup. 3) Using the Evaluation Board with Different Output Voltages While the SP6132 Evaluation Board has been tested and delivered with the output set to 3.30V, by simply changing one resistor, R2, the SP6132 can be set to other output voltages. The relationship in the following formula is based on a voltage divider from the output to the feedback pin VFB, which is set to an internal reference voltage of 0.80V. Standard 1% metal film resistors of surface mount size 0603 are recommended. Vout = 0.80V ( R1 / R2 + 1 ) or R2 = R1 / [ ( Vout / 0.80V ) - 1 ] Where R1 = 68.1K and for Vout = 0.80V setting, simply remove R2 from the board. Furthermore, one could select the value of R1 and R2 combination to meet the exact output voltage setting by restricting R1 resistance range such that 50K R1 100K for overall system loop stability. Note that since the SP6132CU Evaluation Board design was optimized for 12V down conversion to 3.30V, changes of output voltage and/or input voltage will alter performance from the data given in the Power Supply Data section. In addition, the SP6132CU provides short circuit protection by sensing Vout at GND however for a better and robust current limit a comparator circuit could be used as shown on the SP6132EB Schematic. POWER SUPPLY DATA The SP6132 is designed with a very accurate 1.0% reference over line, load and temperature. Figure 1 data shows a typical SP6132CU Evaluation Board Efficiency plot, with efficiencies to 94% and output currents to 10A. SP6132CU Load Regulation shown in Figure 2 shows only 0.3% change in output voltage from no load to 10A load. Figures 3 and 4 illustrate a 0A to 5.0A and 5.0A to 10A Load Step. Start-up Response in Figures 5, 6 and 7 show a controlled start-up with different output load behavior when power is applied where the input current rises smoothly as the Softstart ramp increases. In Figure 8 the SP6132CU is configured for hiccup mode in response to an output dead short circuit condition and will Softstart until the over-load is removed. Figure 9 and 10 show output voltage ripple less than 60mV at no load to 10A load. While data on individual power supply boards may vary, the capability of the SP6132 of achieving high accuracy over a range of load conditions shown here is quite impressive and desirable for accurate power supply design. 2
100 90 80 70 Efficiency (%) 60 50 40 30 20 10 0 2 4 6 8 10 12
L o a d C u r r e n t (A )
Vout (V)
3 .4 5 3 .4 4 3 .4 3 3 .4 2 3 .4 1 3 .4 0 3 .3 9 3 .3 8 3 .3 7 3 .3 6 3 .3 5 0 2 4 6 8 10 12 L o a d C u rre n t (A )
Vin=12V Vout=3.3V
Vin=12V Vout=3.3V
Figure 1. Efficiency vs Load
Figure 2. Load Regulation
Vin=12V Vout=3.3V Vout
Vin=12V Vout=3.3V Vout
Iout (5A/div) Iout (5A/div)
Figure 3. Load Step Response: 0->5A
Figure 4. Load Step Response: 5->10A
Vout Vin SoftStart
Vout Vin SoftStart
Iout (5A/div)
Iout (5A/div)
Figure 5. Start-Up Response: No Load
Figure 6. Start-Up Response: 5A Load
Vout SoftStart SoftStart Iout (5A/div) Ichoke(10A/div)
Vin
Vout
Figure 7. Start-Up Response: 10A Load
Figure 8. Output Load Short Circuit
3
+5V BIAS SUPPLY APPLICATION SCHEMATIC In this application example, the SP6132CU is power by an external +5V bias supply which current consumption of 20mA Maximum. If this supply is not available than it is recommend Sipex SPX5205 Low-Noise LDO Voltage Regulator which is included on the 6132CU Evaluation Board.
GH & GL
GH & GL
Vout ripple = 30mV
Vout ripple = 60mV
Ichoke(5A/div) Ichoke(5A/div)
Figure 9. Output Ripple: No Load
Figure 10. Output Ripple: 10A Load
4
The SP6132EB is design for ease of a quick modification to accommodate for applications that required both different input/output load voltage and current levels. The change such that modification requiring only simple few on board components direct replacement as show on the following Table 1. Table 1: SP6132EB Suggested Components
SP6132EB Suggested Components for Different Input Voltage and Output Current Applications
QT, QB DS L1 C1, C2 C3, C4 R4 R5
5V Input, 2A Output
Fairchild Semi OUTEasy Magnet TDK TDK Panasonic FDS6162N3 SD75-6R8M C3225X5R0J476M C3225X5R0J476M ERJ-3EKF3322V 20V, 21A, 4.5mOhm 6.8uH, 2.54Arms,46mOhm 47uF Ceramic X5R 6.3V 47uF Ceramic X5R 6.3V 332K Ohm, 1% Layout Size SO-8 Layout Size 7.8 x 7.0 mm Layout Size 1210 Layout Size 1210 Layout Size 0603 C1 IN and C2 OUT C3 IN and C4 OUT Yageo America 9C06031A0R0JLHFT 0.0 Ohm, 1% Layout Size 0603
5V Input, 0 to 15A Output
Fairchild Semi OUTEasy Magnet FDS6162N3 SC5018-2R7M 20V, 21A, 4.5mOhm 2.7uH, 15.0A, 4.10mOhm Layout Size SO-8 Layout Size 12.6 x 12.6 mm TDK TDK Panasonic C3225X5R0J476M C3225X5R0J476M ERJ-3EKF3322V 47uF Ceramic X5R 6.3V 47uF Ceramic X5R 6.3V 332K Ohm, 1% Layout Size 1210 Layout Size 1210 Layout Size 0603 Yageo America 9C06031A0R0JLHFT 0.0 Ohm, 1% Layout Size 0603
12V Input, 2A Output
Fairchild Semi FDS7088N3 30V, 21A, 5mOhm Layout Size SO-8 IN Easy Magnet SD75-6R8M 6.8uH, 2.54Arms,46mOhm Layout Size 7.8 x 7.0 mm TDK C3225X5R1C226M 22uF Ceramic X5R 16V Layout Size 1210 C1 IN and C2 OUT TDK Panasonic C3225X5R0J476M ERJ-3EKF1003V 47uF Ceramic X5R 6.3V 100K Ohm, 1% Layout Size 1210 Layout Size 0603 C3 IN and C4 OUT TDK MMZ1608R601A High Freq Bead Filter Layout Size 0603
12V Input, 0 to 15A Output
Fairchild Semi FDS7088N3 30V, 21A, 5mOhm Layout Size SO-8 IN Easy Magnet SC5018-2R7M 2.7uH, 15.0A, 4.10mOhm Layout Size 12.6 x 12.6 mm TDK C3225X5R1C226M 22uF Ceramic X5R 16V Layout Size 1210 TDK Panasonic C3225X5R0J476M ERJ-3EKF1003V 47uF Ceramic X5R 6.3V 100K Ohm, 1% Layout Size 1210 Layout Size 0603 TDK MMZ1608R601A High Freq Bead Filter Layout Size 0603
NOTES: Referring to +5V Bias Supply Application Schematic, DS (STPS2L25U) OUT meaning the application is not required to installed and vice versa. The same argument is also applying both to C2, C4 OUT and C2, C4 IN.
5
LOOP COMPENSATION DESIGN The open loop gain of the SP6132EB can be divided into the gain of the error amplifier Gamp(s), PWM modulator Gpwm, buck converter output stage Gout(s), and feedback resistor divider Gfbk. In order to crossover at the selecting frequency fco, the gain of the error amplifier has to compensate for the attenuation caused by the rest of the loop at this frequency. The goal of loop compensation is to manipulate the open loop frequency response such that its gain crosses over 0dB at a slope of -20dB/dec. The open loop crossover frequency should be higher than the ESR zero of the output capacitors but less than 1/5 of the switching frequency fs to insure proper operation. Since the SP6132EB is designed with a Ceramic Type output capacitors, a Type III compensation circuit is required to give a phase boost of 180 in order to counteract the effects of the output LC under damped resonance double pole frequency.
Figure 11. SP6132EB Voltage Mode Control Loop with Loop Dynamic The simple guidelines for positioning the poles and zeros and for calculating the component values for a Type III compensation are as follows. a. b. c. d. e. Choose fco = fs / 5 Calculate fp_LC fp_LC = 1 / 2 [(L) (C)] ^ 1/2 Calculate fz_ESR fz_ESR = 1 / 2 (Resr) (Cout) Select R1 component value such that 50k R1 100k Calculate R2 base on the desired Vout R2 = R1 / [(Vout / 0.80V) - 1] 6
f. g. h. i.
Select the ratio of Rz2 / R1 gain for the desired gain bandwidth Rz2 = (R1) (Vramp_pp / Vin) (fco / fp_LC) Calculate Cz2 by placing the zero at 1/2 of the output filter pole frequency Cz2 = 1 / (Rz2) (fp_LC) Calculate Cp1 by placing the first pole at ESR zero frequency Cp1 = 1 / 2 (Rz2) (fz_ESR) Calculate Rz3 by setting the second pole at 1/2 of the switching frequency and the second zero at the output filter double pole frequency Rz3 = 2 (R1) (fp_LC) / fs Calculate Cz3 from Rz3 component value above Cz3 = 1 / (Rz3) (fs) Choose 100pF Cf1 220pF to stabilize the SP6132CU internal Error Amplify
j. k.
As a particular example, consider for the following SP6132EB with a type III Voltage Loop Compensation component selections: Vin = 5 to 12V Vout = 3.30V @ 0 to 10A load Select L = 2.7uH => yield 20% of maximum 10A output current ripple. Select Cout = 2x47uF Ceramic capacitors (Resr 2m) fs = 300khz SP6132CU internal Oscillator Frequency Vramp_pp = 1.0V SP6132CU internal Ramp Peak to Peak Amplitude Step by step design procedures: a. b. c. d. e. f. g. h. i. j. k. fco = 300khz / 5 = 60khz fp_LC = 1 / 2 [(2.7uH)(2)(47uF)]^1/2 10khz fz_ESR = 1 / 2 (2m)(2)(47uF) 850khz R1 = 68.1k, 1% R2 = 68.1k / [(3.30V / 0.80V) - 1] 21.5k, 1% Rz2 = 68.1k (1.0V / 12V) (60khz / 10khz) 40.2k, 1% Cz2 = 1 / (40.2k) (10khz) 820pF, COG Cp1 = 1 / 2 (40.2k) (850khz) 5pF => Select Cp1 = 56pF for noise filtering Rz3 = 2 (68.1k) (10khz) / 300khz 4.64k, 1% Cz3 = 1 / (4.64k) (300khz) 220pF, COG Cf1 = 100pF to stabilize SP6132CU internal Error Amplify 7
PC LAYOUT DRAWINGS
Figure 11. SP6132EB Component Placement
Figure 12. SP6132EB PC Layout Top Side
Figure 13. SP6132EB PC Layout Bottom Side
8
Table 2: SP6132EB List of Materials
SP6132 Evaluation Board List of Materials Line No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 Ref. Des. PCB U1 U2 U3 QT, QB DS DBST L1 C3, C4 C1, C2 CVCC C6, C8 C5, CBST C7 CSS CP1 CZ2 CF1 CZ3 R5 RZ2 R2 RZ3 R1 R3 R4, R6 R7, R8 R9, R10 RFL J1 (J1) VIN, VOUT, VCC, GND, GND2, GND3 UVIN, SS Qty. 1 1 1 1 2 1 1 1 2 2 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 1 1 1 6 2 Manuf. Part Number Sipex 146-6521-01 Sipex SP6132EB Sipex SP5205M5-5.0 National Semi LM397MF Fairchild Semi FDS6676S STMicroelectronics STPS2L25U ON-Semi MBR0530 Easy Magnet SC5018-2R7M TDK C3225X5R0J476M TDK C3225X5R1C226M TDK C2012X5R0J106M TDK C1608X5R1C103K TDK C1608X5R1A105K TDK C1608X7R1H104K TDK C1608X7R1H473K TDK C1608COG1H560J TDK C1608COG1H821J TDK C1608COG1H101J TDK C1608COG1H221J TDK MMZ1608R601A Panasonic ERJ-3EKF4022V Panasonic ERJ-3EKF2152V Panasonic ERJ-3EKF4641V Panasonic ERJ-3EKF6812V Panasonic ERJ-3EKF2212V Panasonic ERJ-3EKF1003V Panasonic ERJ-3EKF1502V Panasonic ERJ-3EKF1004V Yageo America 9C06031A3R0JLHFT Sullins PTC36SAAN Sullins STC02SYAN Vector Electronic K24C/M Mill-Max 3137-3002-10-0080 Manuf. Layout Size 1.75"X2.75" MSOP-10 SOT-23-5 SOT-23-5 SO-8 SMB SOD-123 12.6X12.6mm 1210 1210 0805 0603 0603 0603 0603 0603 0603 0603 0603 0603 0603 0603 0603 0603 0603 0603 0603 0603 0603 .32x.12 .2x.1 .042 Dia .042 Dia Component SP6132 Eval PCB 2-15A Any-FET Buck Ctrl 150mA LDO Voltage Reg Voltage Comparator NFET 2A Schottky 10A RMS 0.5A Schottky 2.70uH Coil 12A 4.30mohm 47uF Ceramic X5R 6.3V 22uF Ceramic X5R 16V 10uF Ceramic X5R 6.3V 0.01uF Ceramic X5R 16V 1.0uF Ceramic X5R 10V 0.1uF Ceramic X7R 50V 47,000pF Ceramic X7R 50V 56pF Ceramic COG 50V 820pF Ceramic COG 50V 100pF Ceramic COG 50V 220pF Ceramic COG 50V High Frequency Bead Filter 40.2K Ohm Thick Film Res 1% 21.5K Ohm Thick Film Res 1% 4.64K Ohm Thick Film Res 1% 68.1K Ohm Thick Film Res 1% 221K Ohm Thick Film Res 1% 100K Ohm Thick Film res 1% 15.0K Ohm Thick Film Res 1% 1.00M Ohm Thick Film Res 1% 3.0 Ohm Thick Film Res 5% 36-Pin (3x12) Header Shunt Test Point Post Test Point Female Pin
ORDERING INFORMATION Model Temperature Range Package Type SP6132EB...............................0C to +70C.....................SP6132 Evaluation Board SP6132CU.................................. 0C to +70C........................................10-pin MSOP
9

▲Up To Search▲

Price & Availability of SP6132EB

	To Download SP6132EB Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .