QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 544 MICROPOWER STEP-DOWN SWITCHING REGULATOR IN THINSOT LT1934ES6 DESCRIPTION Demonstration circuit 544 features the LT1934 and LT1934-1 wide input range micro power step-down switching regulators. There are two switching regulator circuits in DC544, the LT1934ES6 circuit designed to convert 4.5V~34V input to 3.3V at 250mA output and the LT1934ES6-1 circuit designed for the same input and output voltage at 50mA load current. Each circuit has two jumpers for testing SHDN mode operation and selecting the output voltage setting (3.3V or 5V). Placing the jumper (JP1 & JP3) to “RUN” enables LT1934 step down converter operation and placing the jumper to “SHDN” disables the LT1934 and the circuit will turn off. The output voltage jumper (JP2 & JP4) changes the feedback resistor value to change the output voltage. Placing the jumper at “3.3V” sets the output to 3.3V and placing the jumper at “5V” sets the output voltage to 5V. For 5V output operation, the input voltage range needs to be 6.5V ~34V. The aluminum electrolytic input capacitor is used at the input for damping the voltage overshoot ringing caused by a low impedance voltage source and a long input power cable (LC tank). See Application Note 88 for more details. Design files for this circuit board are available. Call the LTC factory. Table 1. Performance Summary PARAMETER CONDITION VALUE Minimum Input Voltage For 3.3V output, 6.5V Min. for 5V output 4.5V Maximum Input Voltage Maximum Output Current 34V 4.5V~34V input to 3.3V output VOUT REG 250mA ≅ 60mV QUICK START PROCEDURE UPPER CIRCUIT (BOOST CONVERTER) Refer to Figure 1 for proper measurement equipment setup and follow the procedure below: 1. Connect the input power supply (set at 7V initially) to the Vin and GND pins. 2. Turn on the input power supply and observe the output voltage. The output voltage should read 3.3V ± 0.06V. 3. Test the SHDN function by moving the JP1 jumper from RUN to SHDN (turn on the load box preset at 250mA for a few seconds to discharge the output capacitor). The output should read 0V. 4. Return the jumper back to RUN. The output voltage should now read 3.3V ± 0.06V. 5. Turn on the load box preset at 250mA. The input current should read ≅ 150mA and the output voltage should be 3.3V ± 0.06V. 6. Slowly change the input power supply voltage from 4.5V to 34V while observing the output voltage. The output should stay within 3.3V ± 0.06V. 7. Observe the input current at 34V, it should read ≅ 35mA. 8. Change the input power supply voltage back to 7V and check the output ripple using the oscilloscope. The output ripple should not be higher than 50mV. Also check the switching frequency. The period should be 3uS. 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 544 MICROPOWER STEP-DOWN SWITCHING REGULATOR IN THINSOT LOWER CIRCUIT (BOOST CONVERTER) Refer to Figure 1 for proper measurement equipment setup and follow the procedure below: 1. Connect the input power supply (set at 7V initially) to the Vin and GND pins. 2. Turn on the input power supply and observe the output voltage. The output voltage should read 3.3V ± 0.06V. 3. Test the SHDN function by moving the JP1 jumper from RUN to SHDN (turn on the load box preset at 50mA for a few seconds to discharge the output capacitor). The output should read 0V. 4. Return the jumper back to RUN. The output voltage should read 3.3V ± 0.06V. 5. Turn on the load box preset at 50mA. The input current should read ≅ 30mA and the output voltage should be 3.3V ± 0.06V. 6. Slowly change the input power supply voltage from 4.5V to 34V while observing the output voltage. The output should stay within 3.3V ± 0.06V. 7. Observe the input current at 34V, it should read ≅ 10mA. 8. Change the input power supply voltage back to 7V and check the output ripple using the oscilloscope. The output ripple should not be higher than 40mV. Also check the switching frequency. The period should be 3uS. 2 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 544 MICROPOWER STEP-DOWN SWITCHING REGULATOR IN THINSOT 3 5 4 3 2 1 D1 U1 LT1934ES6 1 Vin 4.5V to 34V 1N4148WS C1 0.22uF BOOST 5 D 1 E1 RUN 2 4 SHDN C3 2.2uF 6 SHDN FB 3 L1 47uH E2 D R1 C2 634K 10pF + C5 68uF 6.3V POSCAP GND 2 D2 B0540W R2 383K R3 464K 1 C4 10uF SW R4 511K 3 + JP1 VIN Vout 3.3V@250mA 5V@200mA 5V 3.3V JP2 2 GND 3 GND C E4 E3 C D3 U2 LT1934ES6-1 1 Vin 4.5V to 34V BOOST 5 RUN B 2 4 SHDN C8 10uF C9 1.0uF SW 6 FB 3 R7 511K SHDN 150uH E6 R9 C7 634K 10pF + C10 68uF 6.3V POSCAP GND 3 + JP3 VIN Vout 3.3V@60mA 5V@45mA 2 D4 B0540W R11 383K R10 464K B 1 1 E5 1N4148WS C11 0.22uF L2 JP4 5V 3.3V 2 GND 3 GND E7 E8 CONTRACT NO. APPROVALS A DRAWN DATE June Wu 6/10/02 Dave Kim 6/10/02 CHECKED TECHNOLOGY TITLE A LT1934ES6/LT1934ES6-1 Micropower Step-Down Switching Regulators in ThinSOT APPROVED ENGINEER 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 DESIGNER SIZE CAGE CODE DWG NO REV A DEMO CIRCUIT 544A Thursday, December 12, 2002 5 4 3 SCALE: 2 FILENAME: SHEET 1 1 OF 1 Bill Of Material Demo Bd. #544A Linear Technology Corporation LT1934ES6/ LT1934ES6-1 6/17/2005 Item Qty Reference 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 2 2 1 1 2 2 2 2 8 4 4 1 1 2 2 2 2 1 1 1 C11,C1 C2,C7 C3 C9 C4,C8 C5,C10 D1,D3 D2,D4 E1-E8 JP1-JP4 JP1-JP4 L1 L2 R1,R9 R2,R11 R3,R10 R7,R4 U1 U2 Part Description CAP., X7R, 0.22uF, 10V, 20% 0603 CAP., C0G, 10pF, 50V, 10% 0402 CAP., X5R, 2.2uF, 35V, 20% 1210 CAP., X5R, 1.0uF, 35V, 20% 1206 CAP., Aluminum, 10uF, 35V 5X6.0 CAP., POSCAP, 68uF, 6.3V B2 SIZE DIODE, 1N4148WS, SOD-323 Schottky Barrier REC., B0540W, SOD-123 TESTPOINT, TURRET, .094" 0.079 SINGLE ROW HEADER, 3PIN SHUNT, INDUCTOR, 47uH, CDH4D28 INDUCTOR, 150uH, DO1608 RES., CHIP, 634K, 1/16W, 1% 0402 RES., CHIP, 383K, 1/16W, 1% 0402 RES., CHIP, 464K, 1/16W, 1% 0402 RES., CHIP, 511K, 1/10W, 1% 0805 I.C. LT1934ES6, Thin SOT23-6 I.C. LT1934ES6-1, Thin SOT23-6 PRINTED CIRCUIT BOARD Page 1 - of - 1 Manufacture / Part # AVX, 0603ZC224MAT2A AVX, 04025A100KAT2A Taiyo Yuden, GMK325BJ225MN Taiyo Yuden, GMK316BJ105ML SANYO, 35CV10AX SANYO, 6TPB68M DIODES INC., 1N4148WS-7 DIODES INC., B0540W-7 MILL-MAX, 2501-2 COMM CON, 2802S-03-G1 COMM CON, CCIJ2MM-138G SUMIDA, CDRH4D28-470 COILCRAFT, DO1608C-154 AAC, CR05-6343FM AAC, CR05-3833FM AAC, CR05-4643FM AAC, CR10-5113FM LINEAR, LT1934ES6 LINEAR, LT1934ES6-1 DEMO CIRCUIT #544A