V1.00: ------ (1) Don't populate C5. It interferes with the cable tie. (2) Make sure the 'I_SET' jumper is 100% FLUSH on the bottom of the circuit board, so it doesn't interfere with the battery. Add 1 layer of tesa-strip around the battery for additional insulation in that area. (3) TS2940CW50 - voltage regulator unstable _again_ Change LED resistor (RLED1) to allow for 10mA of current. (4) The BZX84C-5V1 Zener diodes open too early and clip at about 4.50V instead of slightly above 5V. This limits the usable input voltage range to about 0-18V-ish. They should be replaced with 5V6 ones. The input-protection diodes of a 5V tolerant microcontroller should do the rest. The 5V6 diodes clamp at about 5.6V to 5.7V. The output resistance on the V_DUT pin is 30k. Assuming an overvoltage condition with 25V on the DUT input, the protection diodes of an attached 5V micro-controller should be able to cope with 5.7V and a maximum current of about 0.8mA. V0.1: ----- (6) Replace the MOSFET based RPP with a single Schottky Diode: MBR1045 - TO-220 package. 45V, 10A. Forward voltage of 0.5V at 5A --> 2.5W. Should survive without a large HS. (5) If you require high current with input voltages below 5V, the reverse polarity protection tends to heat up a lot. DON'T populate: Q3, Q4, R7, DZ1 Place a 2mm jumper wire between JP1 and JP2 to override. This will avoid the magic blue smoke. (4) Added 2x 47µF electrolytic capacitors across the DUT terminals (back to back --> non polarized). (3) TS2940CW50 - Voltage regulator unstable. Change LED resistor to 470Ohm to draw more current. This removes all output voltage oscillations. (2) TS2940CW50 - Voltage regulator unstable. C1 and C2 MUST be tantalum capacitors! (1) TS2940CW50 - Voltage regulator unstable. Don't populate C2 (output capacitor). The datasheet mentions a minimum load of 10mA for the thing to be stable. I couldn't get rid of massive output voltage oscillations as long as C2 was populated, although I added a 100Ohm resistor to draw about 50mA. Tried a different regulator, different cap as well. I've never experienced such misbehaviour before. It worked just fine in previous projects...