DEMO MANUAL DC1801A LTC3838EUHF High Efficiency Dual Output Step-Down DC/DC Converter DESCRIPTION Demonstration circuit 1801A is a dual output 1.5V/20A and 1.2V/20A synchronous buck converter operating with a switching frequency of 300kHz over an input voltage range of 4.5V to 14V. The demo board comes in two versions. The A version uses inductor DCR current sensing for high efficiency. The B version uses 2mΩ sense resistor for accurate current sensing with a low DCR ferrite inductor. The fixed on-time valley current mode topology of the LTC3838 allows for a fast load step response (see Figures 6 to 9). The load step response can be tested with the onboard load step circuit and a bench pulse generator. The demo board uses a high density, two sided drop in layout. The entire converter, excluding the bulk output and input capacitors, fits within a compact 1.5” × 1.0” area on the board. The package style for the LTC3838EUHF is a 38-pin QFN with an exposed ground pad. PERFORMANCE SUMMARY PARAMETER The main features of the board are listed below: • MODE jumper to program either discontinuous mode (DCM) or forced continuous mode (FCM) at light or no load. • EXTVCC pin. • PLLIN pin to synchronize the converter to an external clock. • Remote sensing for VOUT1. • Optional resistors to tie the two phases together. • Each rail has its own RUN pin, PGOOD pin and TRACK/SS pin. Design files for this circuit board are available at http://www.linear.com/demo L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. (TA = 25°C) CONDITIONS Minimum Input Voltage VALUE 4.5V Maximum Input Voltage 14V Output Voltage VOUT1 IOUT1 = 0A to 20A, VIN = 4.5V to 14V Output Voltage VOUT2 IOUT2 = 0A to 20A, VIN = 4.5V to 14V 1.5V ± 2% VOUT1 Maximum Output Current, IOUT1 VIN = 4.5V to 14V, VOUT1 = 1.2V 20A VOUT2 Maximum Output Current, IOUT2 VIN = 4.5V to 14V, VOUT2 = 1.5V 20A Nominal Switching Frequency 1.2V ± 2% 300kHz VOUT1 = 1.2V, IOUT1 = 20A, VIN = 12V 91% Typical See Figures 2 and 3 VOUT2 = 1.5V, IOUT2 = 20A, VIN = 12V 92% Typical -B Efficiency (RSENSE Current Sense) VOUT1 = 1.2V, IOUT1 = 20A, VIN = 12V 89.5% Typical See Figures 4 and 5 VOUT2 = 1.5V, IOUT2 = 20A, VIN = 12V 91% Typical -A Efficiency (DCR Current Sense) dc1801af 1 DEMO MANUAL DC1801A QUICK START PROCEDURE Demonstration circuit 1801A is easy to set up to evaluate the performance of the LTC3838EUHF. Please refer to Figure 1 for proper measurement equipment setup and follow the procedure below. 1) With power off, connect the input supply, load and meters as shown in Figure 1. Preset the load to 0A and VIN supply to be 0V. Place jumpers in the following positions: JP4 RUN1 ON JP1 RUN2 ON JP3 MODE FCM 2) Adjust the input voltage to be between 4.5V to 14V. VOUT1 should 1.2V ± 2%. VOUT2 should 1.5V ± 2%. 3) Next, apply 20A load and recheck VOUT. 4) Once the DC regulation is confirmed, observe the output voltage ripple, load step response, efficiency and other parameters. Note 1. Use the BNC connectors labeled VOUT1 or VOUT2 to measure the output voltage ripple. tor the voltage across COUT1 and COUT5 respectively. Heavy load currents applied across these turrets may damage the converter. LOAD STEP TRANSIENT TESTING Demonstration circuit 1801A provides a simple load step circuit consisting of a MOSFET and sense resistor for each rail. To apply a load step, follow the steps below. 1) Preset the amplitude of a pulse generator to 0.0V and the duty cycle to 5% or less. 2) Connect the scope to the VOUT BNC connectors for the rail under test with a coax cable. To monitor the load step current, connect the scope probe across the IOSTEP+/– turrets for that rail. 3) Connect the output of the pulse generator to the PULSE GEN turret for the rail under test and connect the return to one of the GND turrets. 4) With the converter running, slowly increase the amplitude of the pulse generator output to provide the desired load step pulse height. The scaling for the LOAD STEP signal is 10mV/Amp. Note 2. Do not apply the load from the VO1_SNS+ turret to the VO1_SNS– turret or from the VO2+ turret to the VO2– turret. These turrets are only intended to moni- dc1801af 2 DEMO MANUAL DC1801A QUICK START PROCEDURE A single output/dual phase converter may be preferred for high output current applications. The benefits of single output/dual phase operation is lower ripple current through the input and output capacitors, faster load step response and simplified thermal design. To implement single output/ dual phase operation, make the following modifications: • Tie VOUT1 to VOUT2 by tying together the exposed copper pads on the VOUT shapes with pieces of heavy copper foil. • Remove the ITH compensation network, VFB divider and TRACK/SS capacitor for phase-2. • Tie VRNG1 to VRNG2 by stuffing 0Ω at R4. • Tie RUN1 to RUN2 by stuffing 0Ω at R7. • If the optional transient detect circuit is used, externally tie the DTR1 pin to the DTR2 pin. • Recompensate if necessary. • Tie VFB2 to INTVCC by stuffing 0Ω at R1. This will disable the error amp for phase-2 and internally tie the two ITH signals together. Figure 1. Proper Measurement Equipment Setup dc1801af 3 DEMO MANUAL DC1801A QUICK START PROCEDURE 95 100 fSW = 300kHz VIN = 12V 90 fSW = 300kHz VIN = 12V 80 90 EFFICIENCY (%) EFFICIENCY (%) 70 85 80 60 50 40 30 1.5V FCM 1.2V FCM 1.5V DCM 1.2V DCM 20 75 10 1.5V FCM 1.2V FCM 0 0.01 70 1 6 11 LOAD CURRENT (A) 21 16 0.1 1 LOAD CURRENT (A) DC1801a F03 DC1801a F02 Figure 2. Efficiency Curves for the DC1801A-A (DCRSENSE) in FCM 95 10 Figure 3. Efficiency Curves for the DC1801A-A (DCRSENSE) in FCM and DCM. 100 fSW = 300kHz VIN = 12V 90 90 fSW = 300kHz VIN = 12V 80 EFFICIENCY (%) EFFICIENCY (%) 70 85 80 60 50 40 30 75 1.5V FCM 1.2V FCM 1.5V DCM 1.2V DCM 20 10 1.5V FCM 1.2V FCM 70 1 6 11 LOAD CURRENT (A) 16 21 DC1801a F04 Figure 4. Efficiency Curves for the DC1801A-B (RSENSE) in FCM 0 0.01 0.1 1 LOAD CURRENT (A) 10 DC1801a F05 Figure 5. Efficiency Curves for the DC1801A-B (RSENSE) in FCM and DCM dc1801af 4 DEMO MANUAL DC1801A QUICK START PROCEDURE 15A 5A LOAD STEP 1.2VO 50mV/DIV 106mV 20μs/DIV DC1801a F06 Figure 6. Load Step Response of the 1.2V Rail on the DC1801A-A (DCRSENSE) at VIN = 12V. COUT = 2× Sanyo 2R5TPE330M9 || 2× 100μF X5R 6.3V 1206, L = 0.47μH, fSW = 300kHz 15A LOAD STEP 5A 1.5VO 50mV/DIV 127mV 20μs/DIV DC1801a F07 Figure 7. Load Step Response of the 1.5V Rail on the DC1801A-A (DCRSENSE) at VIN = 12V. COUT = 2× Sanyo 2R5TPE330M9 || 2× 100μF X5R 6.3V 1206, L = 0.47μH, fSW = 300kHz dc1801af 5 DEMO MANUAL DC1801A QUICK START PROCEDURE 15A LOAD STEP 5A 1.2VO 50mV/DIV 112mV 20μs/DIV DC1801a F08 Figure 8. Load Step Response of the 1.2V Rail on the DC1801A-B (RSENSE) at VIN = 12V. COUT = 2× Sanyo 2R5TPE330M9 || 2× 100μF X5R 6.3V 1206, fSW = 300kHz, L = 0.44μH, fSW = 300kHz 15A LOAD STEP 5A 1.5VO 50mV/DIV 119mV 20μs/DIV DC1801a F09 Figure 9. Load Step Response of the 1.5V Rail on the DC1801A-B (RSENSE) at VIN = 12V. COUT = 2× Sanyo 2R5TPE330M9 || 2× 100μF X5R 6.3V 1206, fSW = 300kHz, L = 0.44μH, fSW = 300kHz dc1801af 6 DEMO MANUAL DC1801A PARTS LIST Demo Board 1801A-A ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 CIN1 CAP, 180μF, 16V, SVP-F8 SANYO, 16SVP180MX 2 2 CIN3, CIN5 CAP, X5R, 22μF, 16V, 1210 MURATA, GRM312ER61C226KE20L 3 4 COUT1, COUT2, COUT5, COUT6 CAP, 330μF, 2.5V, SIZE 7343 SANYO, 2R5TPE330M9 4 4 COUT3, COUT4, COUT7, COUT8 CAP, X5R, 100μF, 6.3V, 1206 MURATA, GRM31CR60J107ME39L 5 2 C3, C16 CAP, X6R, 0.22μF, 25V, 0603 MURATA, GRM188R60E224KA88D 6 5 C4, C5, C10, C13, C14 CAP, X5R, 0.1μF, 16V, 0603 AVX, 0603YD104KAT2A 7 2 C6, C11 CAP, NPO, 47pF, 16V, 0603 AVX, 0603YA470JAT2A 8 2 C7, C12 CAP, X7R, 470pF, 16V, 0603 AVX, 0603YC471JAT2A 9 1 C8 CAP, X5R, 4.7μF, 16V, 0805 AVX, 0805YD475KAT2A 10 2 C9, C18 CAP, X5R, 1μF, 16V, 0603 AVX, 0603YD105KAT2A 11 2 D1, D2 DIODE, SCHOTTKY, SOD-323 CENTRAL SEMI, CMDSH-4E TR 12 2 L1, L2 IND, 0.47μH WÜRTH, 744355047 13 2 Q1, Q3 MOSFET, OPTIMOS, PG-TDSON-8 INFINEON, BSC050NE2LS 14 2 Q2, Q4 MOSFET, OPTIMOS, PG-TDSON-8 INFINEON, BSC010NE2LS 15 2 Q9, Q10 MOSFET, N-CH, 30V, TO-252 VISHAY, SUD50N03-12P-E3 16 7 R8, R11, R16, R35, R39, R55, R57 RES, CHIP, 0, 0603 VISHAY, CRCW06030000Z0EA 17 2 R12, R38 RES, CHIP, 100k, 1%, 0603 VISHAY, CRCW0603100KFKEA 18 3 R13, R21, R31 RES, CHIP, 15k, 1%, 0603 VISHAY, CRCW060315K0FKEA 19 0 R14, R15, R24, R29, R41, R45 (OPT) RES, CHIP, 0603 20 4 R17, R23, R40, R46 RES, CHIP, 10k, 1%, 0603 21 2 R18, R32 RES, CHIP, 2.15k 1%, 0603 VISHAY, CRCW06032K15FKEAEA 22 4 R20, R26, R30, R36 RES, CHIP, 0, 0603 VISHAY, CRCW06030000Z0EA 23 2 R25, R27 RES, CHIP, 2.2 1%, 0603 VISHAY, CRCW06032R20FKEA 24 1 R28 RES, CHIP, 133k, 1%, 0603 VISHAY, CRCW0603133KFKEA 25 2 R42, R43 RES, CHIP, 10, 1%, 0603 VISHAY, CRCW060310R0FKED 26 2 RS1, RS2 RES, CHIP, 0.000Ω, 2W, 2512 TEPRO, RN5326 27 1 U1 LTC3838EUHF, QFN, 38-LEAD LINEAR TECHNOLOGY LTC3838EUHF VISHAY, CRCW060310K0FKEA Additional Demo Board Circuit Components 1 0 CIN2 (OPT) CAP, OPT, SVP-F8 2 0 CIN4, CIN6, CIN7, CIN8 (OPT) CAP, OPT, 1210 3 0 C1, C2, C15, C17 (OPT) CAP, OPT, 0603 4 0 COUT13 TO COUT16 (OPT) CAP, OPT, 7343 5 0 Q5 TO Q8 (OPT) MOSFET, OPTIMOS, PG-TDSON-8 6 0 R1, R3, R4, R6, R7, R9, R10, R19, R34, R37, R44, R49, R50, R47, R48, R56 (OPT) RES, CHIP, 0603 7 2 R51, R52 RES, CHIP, 10k, 1%, 0603 VISHAY, CRCW060310K0FKEA 8 2 R53, R54 RES, CHIP, 0.01, 1/2W, 1%, 2010 VISHAY, WSL2010R0100FEA dc1801af 7 DEMO MANUAL DC1801A PARTS LIST Demo Board 1801A-A ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Hardware/Components (For Demo Board Only) 1 20 E1 TO E20 TESTPOINT, TURRET, 0.095" MILL-MAX, 2501-2-00-80-00-00-07-0 2 2 JP1, JP4 2mm SINGLE ROW HEADER, 3-PIN SAMTEC, TMM-103-02-L-S 3 2 JP2, JP3 2mm SINGLE ROW HEADER, 4-PIN SAMTEC, TMM-104-02-L-S 4 4 XJP1 TO XJP4 SHUNT SAMTEC, 2SN-BK-G 5 6 J1 TO J6 JACK, BANANA KEYSTONE, 575-4 6 2 J7, J8 CONN, BNC, 5 PINS CONNEX, 112404 7 2 J9, J10 2mm SINGLE ROW HEADER, 2-PIN SAMTEC, TMM-102-02-L-S 8 4 MH1 TO MH4 STAND-OFF, NYLON 0.25" KEYSTONE, 8831 (SNAP ON) dc1801af 8 DEMO MANUAL DC1801A PARTS LIST Demo Board 1801A-B ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 CIN1 CAP, 180μF, 16V, SVP-F8 SANYO, 16SVP180MX 2 2 CIN3, CIN5 CAP, X5R, 22μF, 16V, 1210 MURATA, GRM312ER61C226KE20L 3 4 COUT1, COUT2, COUT5, COUT6 CAP, 330μF, 2.5V, SIZE 7343 SANYO, 2R5TPE330M9 4 4 COUT3, COUT4, COUT7, COUT8 CAP, X5R, 100μF, 6.3V, 1206 MURATA, GRM31CR60J107ME39L 5 2 C3, C16 CAP, X7R, 1000pF, 16V, 0603 AVX, 0603YC102KAT2A 6 5 C4, C5, C10, C13, C14 CAP, X5R, 0.1μF, 16V, 0603 AVX, 0603YD104KAT2A 7 2 C6, C11 CAP, NPO, 47pF, 16V, 0603 AVX, 0603YA470JAT2A 8 2 C7, C12 CAP, X7R, 470pF, 16V, 0603 AVX, 0603YC471JAT2A 9 1 C8 CAP, X5R, 4.7μF, 16V, 0805 AVX, 0805YD475KAT2A 10 2 C9, C18 CAP, X5R, 1μF, 16V, 0603 AVX, 0603YD105KAT2A 11 2 D1, D2 DIODE, SCHOTTKY, SOD-323 CENTRAL SEMI, CMDSH-4E TR 12 2 L1, L2 IND, 0.44μH COOPER, FP1308R3-R44-R 13 2 Q1, Q3 MOSFET, OPTIMOS, PG-TDSON-8 INFINEON, BSC050NE2LS 14 2 Q2, Q4 MOSFET, OPTIMOS, PG-TDSON-8 INFINEON, BSC010NE2LS 15 2 Q9, Q10 MOSFET, N-CH, 30V, TO-252 VISHAY, SUD50N03-12P-E3 16 7 R8, R11, R16, R35, R39, R55, R57 RES, CHIP, 0, 0603 VISHAY, CRCW06030000Z0EA 17 2 R12, R38 RES, CHIP, 100k, 1%, 0603 VISHAY, CRCW0603100KFKEA 18 3 R13, R21, R31 RES, CHIP, 15k, 1%, 0603 VISHAY, CRCW060315K0FKEA 19 4 R14, R15, R41, R45 RES, CHIP, 10, 1%, 0603 VISHAY, CRCW060310R0FKED 20 4 R17, R23, R40, R46 RES, CHIP, 10k, 1%, 0603 VISHAY, CRCW060310K0FKEA 21 2 R24, R29 RES, CHIP, 0, 0603 VISHAY, CRCW06030000Z0EA 22 2 R25, R27 RES, CHIP, 2.2 1%, 0603 VISHAY, CRCW06032R20FKEA 23 1 R28 RES, CHIP, 133k, 1%, 0603 VISHAY, CRCW0603133KFKEA 24 2 R42, R43 RES, CHIP, 10, 1%, 0603 VISHAY, CRCW060310R0FKED 25 2 RS1, RS2 RES, CHIP, 2mΩ, 2W, 1%, 2512 VISHAY, WSL25122L000FEA 26 1 U1 LTC3838EUHF, QFN, 38-LEAD, LINEAR TECHNOLOGY LTC3838EUHF Additional Demo Board Circuit Components 1 0 CIN2 (OPT) CAP, OPT, SVP-F8 2 0 CIN4, CIN6 TO CIN8 (OPT) CAP, OPT, 1210 3 0 C1, C2 ,C15, C17 (OPT) CAP, OPT, 0603 4 0 COUT13 TO COUT16 (OPT) CAP, OPT, 7343 5 0 Q5 TO Q8 (OPT) MOSFET, OPTIMOS, PG-TDSON-8 6 0 R1, R3, R4, R6, R7, R9, R10, R19, R34, R37, R44, R49, R50, R47, R48, R56 (OPT) RES, CHIP, 0603 7 2 R51, R52 RES, CHIP, 10k, 1%, 0603 VISHAY, CRCW060310K0FKEA 8 2 R53, R54 RES, CHIP, 0.01, 1/2W, 1%, 2010 VISHAY, WSL2010R0100FEA 9 0 R18, R20, R26, R30, R32, R36 (OPT) RES, CHIP, 0603 dc1801af 9 DEMO MANUAL DC1801A PARTS LIST Demo Board 1801A-B ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Hardware/Components (For Demo Board Only) 1 20 E1 TO E20 TESTPOINT, TURRET, 0.095" MILL-MAX, 2501-2-00-80-00-00-07-0 2 2 JP1 TO JP4 2mm SINGLE ROW HEADER, 3-PIN SAMTEC, TMM-103-02-L-S 3 2 JP2, JP3 2mm SINGLE ROW HEADER, 4-PIN SAMTEC, TMM-104-02-L-S 4 4 XJP1 TO XJP4 SHUNT SAMTEC, 2SN-BK-G 5 6 J1 TO J6 JACK, BANANA KEYSTONE, 575-4 6 2 J7, J8 CONN, BNC, 5 PINS CONNEX, 112404 7 2 J9, J10 2mm SINGLE ROW HEADER, 2-PIN SAMTEC, TMM-102-02-L-S 8 4 MH1 TO MH4 STAND-OFF, NYLON 0.25" KEYSTONE, 8831 (SNAP ON) dc1801af 10 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. A B C D 1 E4 R39 R50 OPT RUN1 E19 E16 C18 1uF E15 EXTVCC E14 2 R49 JMP1X3 OPT VIN TRK/SS1 C17 OPT R44 OPT VOUT2 R37 OPT E10 0 E9 R10 OPT R47 OPT -A (DCR SENSE) -B (RSENSE) ASSY * 15K R30 C14 R31 15K * 0.1uF 5 * 0 R57 OPT INTVCC 0.22uF 1000pF C3, C16 C12 470pF R28 133K C11 47pF * R29 R24 WURTH 744355047 (0.47uH) COILTRONICS FP1308R3-R44-R (0.44uH) L1,L2 R26 R56 C6 47pF C7 470pF R21 FSW = 300kHz 2. INSTALL SHUNTS ON JUMPERS AS SHOWN. 1. ALL RESISTORS 0603. ALL CAPACITORS ARE 0603. 0 C5 0.1uF R17 10K R13 15K VFB2 R55 OPT NOTE: TIE SGND PIN TO PGND PAD UNDERNEATH IC. INTVCC C2 OPT R9 NOTES: UNLESS OTHERWISE SPECIFIED GND EXTVCC PGOOD1 RUN1 ON OFF JP4 RUN1 TRK/SS1 CLKOUT E8 3 2 R23 10K INTVCC PLLIN FCM SYNC DCM JP3 MODE JP2 INTVCC PHASMD CLKOUT 120 DEG 2 90 DEG 3 60 DEG TRK/SS2 C1 OPT TRK/SS2 R8 0 R6 OPT 2.15K OPT R18, R32 4 0 OPT 9 8 7 6 5 4 3 2 1 12 11 10 R20, R36 R46 10K C15 R40 OPT 10K TRK/SS1 VRNG1 VRNG2 TRK/SS2 U1 LTC3838EUHF R11 OPT INTVCC * OPT 10 OPT 0 R14,R15, R24, R41,R45 R29 * R41 * 0 OPT R26, R30 R45 S1+ C16 S1- VOUTSENSE1+ TRACK/SS1 ITH1 VRNG1 RT SGND CLKOUT MODE/PLLIN PHASEMD VRNG2 C3 S2- * R14 R12 100K INTVCC BG2 29 27 R38 100K INTVCC TG1 20 SW1 21 BG1 22 DRVCC1 23 VIN 24 PGND 25 INTVCC 26 EXTVCC C9 0 R35 C10 0.1uF 1uF 3 R27 VOUT1 1 2.2 4 Q2 4 Q1 4 Q4 4 IOSTEP1- IOSTEP1+ E22 E24 4 SW1 BSC010NE2LS 4 BSC050NE2LS 4 SW2 BSC010NE2LS 4 Q3 BSC050NE2LS * L1 R32 CIN3 22uF 16V 1210 * * * R36 R34 OPT CIN5 OPT 1210 S1+ CUSTOMER NOTICE 2512 * RS1 VOUT2 1 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. E25 E23 SCALE = NONE JW DING L. PCB DES. APP ENG. E3 VOUT2 E6 E5 J2 CIN1 J1 + CIN2 + 180uF OPT 16V 16SVP180MX VIN E7 COUT7 + COUT6 + COUT5 J3 330uF 100uF 330uF 2.5V 2.5V 6.3V 7343-D15T 7343-D15T 1206 J4 CIN7 (OPT) 35V 1210 R52 10K VO2- GND VOUT2 1.5V / 20A VO2+ VIN- GND VIN 4.5V - 14V VIN+ R42 10 GND PULSE2 VOUT1 E12 E11 VO1_SNS- VO1_SNS+ J6 DATE: N/A SIZE LTC3838EUHF 1 DEMO CIRCUIT 1801A Tuesday, March 08, 2011 IC NO. SHEET 1 OF 1 1 REV. HIGH EFFIVIENCY DUAL OUTPUT STEP-DOWN DC-DC CONVERTER 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only + COUT15 + COUT16 OPT OPT 7343-D15T 7343-D15T VOUT2 + COUT13 + COUT14 OPT OPT 7343-D15T 7343-D15T VOUT1 ONLY ADD FOOTPRINTS ON SOLDERMASK, DO NOT SHOW IN SCHEMATIC. OPTIONAL COUT R43 10 VOUT1 1.2V / 20A + COUT2 + COUT1 330uF 330uF J5 2.5V 2.5V 7343-D15T 7343-D15T GND TECHNOLOGY E21 TITLE: SCHEMATIC R54 0.01 2010 1 E18 COUT4 COUT3 100uF 100uF 6.3V 6.3V 1206 1206 Q10 SUD50N03-12P VOUT2 APPROVALS IOSTEP2- IOSTEP2+ LOAD STEP 10mV / A 5% DUTY CYCLE MAX J8 COUT8 100uF 6.3V 1206 CIN8 (OPT) 35V 1210 1 COUT1,2,5,6 = Sanyo 2R5TPE330M9 COUT3,4,7,8 = Murata GRM31CR60J107ME39L CIN1 = Sanyo 16SVP180MX CIN3,4 = Murata GRM32ER61C226KE20L Q1,Q3 = Infineon BSC050NE2LS Q2,Q4 = Infineon BSC010NE2LS LOAD STEP CIRCUIT #2 LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. 2 S2- 2512 R20 * RS2 R19 OPT S2+ CIN6 OPT 1210 DCR SENSE FILTER / DIVIDER FOR PHASE 2 * *L2 R18 CIN4 22uF 16V 1210 S1DCR SENSE FILTER / DIVIDER FOR PHASE 1 Q6 OPT Q5 OPT Q8 OPT Q7 OPT PULSE1 E17 R51 GND 10K E20 R53 0.01 2010 1 Q9 SUD50N03-12P VOUT1 LOAD STEP 10mV / A 5% DUTY CYCLE MAX J7 2 Note: Make footprint for Q1-Q8 compatible with LFPAK and PowerPAK MOSFETs. LOAD STEP CIRCUIT #1 C13 D1 0.1uF CMDSH-3 R25 C8 2.2 4.7uF 16V 0805 D2 CMDSH-3 RUN2 R7 OPT C4 0.1uF RUN1 INTVCC EXTVCC 0 INTVCC R1 OPT VRNG1 VRNG2 R4 OPT VFB2 OPTIONAL COMPONENTS FOR SINGLE OUTPUT, DUAL PHASE OPERATION R16 3 0.000 Ohm 2512 TEPRO RN5326 0.002 Ohm 2512 VISHAY WSL25122L000FEA RS1, RS2 R48 0 TG2 31 SW2 30 DRVCC2 28 * TRACK/SS2 PGND 39 ITH2 S2+ * R15 VOUTSENSE113 2 SENSE1+ 14 R3 JMP1X3OPT SENSE2- 36 SENSE115 E2 VIN VFB2 38 VOUT2 35 VOUT1 16 JP1 RUN2 ON OFF SENSE2+ 37 RUN2 34 RUN1 17 RUN2 4 BOOST2 32 PGOOD1 18 3 1 4 1 4 1 PGOOD2 33 BOOST1 19 5 5 4 3 2 3 5 1 2 3 5 1 2 3 5 1 2 3 5 1 2 3 2 3 5 1 2 3 5 1 2 3 5 1 2 3 5 1 2 3 RUN2 5 4 3 2 E1 2 3 PGOOD2 A B C D DEMO MANUAL DC1801A SCHEMATIC DIAGRAM dc1801af 11 DEMO MANUAL DC1801A DEMONSTRATION BOARD IMPORTANT NOTICE Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions: This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations. If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES. The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind. LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive. Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and observe good laboratory practice standards. Common sense is encouraged. This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer. Mailing Address: Linear Technology 1630 McCarthy Blvd. Milpitas, CA 95035 Copyright © 2004, Linear Technology Corporation dc1801af 12 Linear Technology Corporation LT 0212 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2012