The small transformer is made with a rectifier a smoothing capacitor and a zener which gives me about 24 volts DC that I feed into the sg3525 and ir2110, the maximum allowed for the sg is 35 volts and for the ir2110 25volts. Hi all, I'm using an IR2110 high and low side gate driver in a smps that I mentioned some time back in the group under the thread 'should I use a SG3525'. I've had some 'odd' power device failures that I didn't expect in entirely benign situations, such as the half bridge output simply driving the primary of my transformer. I realised that it happened a couple of times when I wound down the input volts ( I'm supplying the board via a variac and isolating transfomer for development ). The IR2110 has undervoltage lockout. I checked it carefully today and the UVLO for the low side and high side aren't linked. Indeed a careful look at the data sheet does indeed show that there's no connection. The low side drive activates at about 8V and the high side about a volt higher. Needless to say this creates 'issues'! Anyone here used this part and care to comment? Regds, Graham. Hi all, I'm using an IR2110 high and low side gate driver in a smps that I mentioned some time back in the group under the thread 'should I use a SG3525'. I've had some 'odd' power device failures that I didn't expect in entirely benign situations, such as the half bridge output simply driving the primary of my transformer. I realised that it happened a couple of times when I wound down the input volts ( I'm supplying the board via a variac and isolating transfomer for development ). The IR2110 has undervoltage lockout. I checked it carefully today and the UVLO for the low side and high side aren't linked. ![]() Indeed a careful look at the data sheet does indeed show that there's no connection. The low side drive activates at about 8V and the high side about a volt higher. Needless to say this creates 'issues'! Anyone here used this part and care to comment? Regds, Graham. Download ultraman zero the revenge of belial sub indo. Click to expand.The 3525 isn't the prob - it does indeed UVLO around 7V and has 300mV of hysteresis. The 2110 low side UVLO appears to be @ 8V and the high side @ around 8.9V. So as the power rails sag the high side device stops conducting but the low side doesn't. Doesn't appear to be any hysteresis on the 2110 either. I reckon I'm going to have to implement my own undervoltage lock out to stop the 3525 @ about 10V. Just curious if anyone else had noticed this. Choice of devices was partly determined / influenced by their use by the major US manufacturer of pro-audio amplifiers in a similar application. Click to expand.Device going short. Either just the high side device or both. I've established to my satisfaction that there are 2 failure scenarios. Ramping the voltage down on the variac ( quickly ). After I've been testing @ line voltage. There's a bzzt and the high side device goes short. I suspect a mixture of the UVLO mismatches and possible 'mis-track' of the main bus and supervisory rail. Doesn't happen if I ramp the volts down slowly ( or so it seems ). Hence my thoughts about the droop of the rails.
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