Shared Projects by thespeakerguy

PDM Generator

See article describing circuit. http://www.electronicdesign.com/displays/resistive-dummy-load-draws-constant-current-12-50-v

All component values and reference designators changed from article though. All load resistors are off PCB too. Use 1% through hole resistors mounted to output banana jacks. U1 is REF3012, U2 is OPA313, and U3, optional, is TPS3702AX18DDCT for checking battery voltage. This version will work off 2 x AAA batteries.

http://www.digikey.com/short/3v9d8r

Item Qty Reference Manufacturer Description Manufacturer Part Number 1 6 C3 C7 C10 C12-14 Yageo Capacitor: Ceramic, 0.1uF, ±10%, 16V, X7R, 0603 CC0603KRX7R7BB104 2 2 C2 C5 Murata Capacitor: Ceramic, 10nF, ±10%, 100V, X7R, 0603 GCM188R72A103KA37D 3 2 C6 C9 Yageo Capacitor: Ceramic, 10uF, ±10%, 16V, 0603 CC0603KRX5R7BB106 4 2 C4 C11 Yageo Capacitor: Ceramic, 1.0uF, ±10%, 16V, 0603 CC0603KRX5R7BB105 5 1 C8 Murata Capacitor: Ceramic, 0.47uF,10%, 10V, 0603,X5R GRM188R61A474KT 6 1 C1 Taiyo Yuden Capacitor: Ceramic, 1uF,100V, X5R, 1206 HMK316BJ105ML-T 7 1 D7 ON Semiconductor Switching Diode, SOD-123, SMT, MMSD4148 MMSD4148T1G 8 1 D1 Diodes Inc Diode, Schottky Barrier Rectifier, 0.5A, 100V SOD-123, SMT MBR0580S1-7 9 1 D2 On Semiconductor Zener Diode: 12V, SOD-323 MM3Z12VT1G 10 2 L1-2 Murata Inductor, Ferrite Bead, 0603, 600R BLM18TG601TN1D 11 2 J6 J8 Sullins Connector, Header: 1x4, 2.54mm pitch, Through hole, Straight
12 1 U2 TI DUAL,LOW POWER OP AMP, SO8 LM358 13 1 L3 Bourns Power inductor: 680uH, 200mA SRR7045-681M 14 1 J7 Sullins Header, receptacle, for LCD, 14 pin SMT NPTC072KFMS-RC 15 1 Q3 Foshan Blue Rocket Electronics Co., Ltd. N-Channel Enhancement MOSFET, SOT-23 2N7002K1 16 2 Q1-2 TI MOSFET N-CH 80V 100A VSON
17 1 Q4 Diodes Inc. MOSFET: P, 100V, 4R, SOT23 DMP10H4D2S-7 18 3 R4 R6 R10 Yageo Chip Resistor: 100K, +/-5%, 1/10W, 0603 RC0603JR-07100KL 19 5 R7 R9 R11-13 Yageo Chip Resistor: 10K, +/-5%, 1/10W, 0603 RC0603JR-0710KL 20 1 R5 ROHM Chip Resistor: 200K, 5%, 1/10W, 0603 MCR03EZ**J204 21 1 R17 Yageo Chip Resistor: 2.2 ohm, ±5%,1/10W, 0603 RC0603JR-072R2L 22 3 R2-3 R14 Rohm Chip Resistor: 330 Ohm, 5%, 1/10W, 0603 MCR03EZHJ331 23 1 R8 Yageo Chip Resistor: 33K, +/-5%, 1/10W, 0603
24 2 R18-19 ROHM Chip Resistor: 470K, ±5%, 1/10W, 0603 MCR03EZHJ-474 25 2 R15-16 ROHM Chip Resistor:47K, 5%, 1/10W, 0603 MCR03EZHJ473 26 1 R1 Panasonic Chip Resistor: 5mOhm, 1%, 3W, 2512 ERJ-MP4QF5M0U 27 1 S1 Omron Tact Switch: Push button, Top Actuated, SPST, N.O., 3.0x2.5mm, SMT B3U-1000P 28 1 U1 TI Micro, TSSOP28 MSP430I2020 29 1 U3 TI IC, Regulator, Buck, 100V, 350mA, VSSOP8 LM5008MM