Hello,
I've 15V as main supply and a 12V lead acid battery to backup it.
I need a voltage limiter circuit to drive a 9~12 siren, and protect from short circuit.
TPS259621 clamp output voltage at 13.8V, using 2x diode I think is possible to use that. But it will dissipate almost 1.2W.
I think that this dissipated power will trigger the therm shutdown.
Is possible to use a pcb footprint to reduce temperature? Do you have another solution for that circuit?
Thank you.
Regard
Leandro
Hi Leandro,
1. Best solution would be to use an LDO after 15V rail to regulate to 9-12V and then feed it to eFuse input.
2. You are assuming 1.2W dissipation because max load current is 1A? If we follow layout guidelines as per datasheet and solder exposed PAD to PCB then low RQJA can be achieved. If we are operating device always in clamping mode then we have to ensure that TJ always stays below 125C. More the TJ of device over lifetime, more is the reliability a concern. You can follow EVM layout also.
3. Other solution is using OVLO variant and connect resistor divider to OUT pin and set OVLO around 10V that way output will be clamped near 10V but follow hysteresis.
Regards
Kunal Goel
