I am designing a low profile space grade buck regulator. I have the following constraints
- ICs must be space grade
- Low component count
- Small size
The converter specifications are as follows. Input voltage varying from 15-25V, Required outputs at 3.8V or 5.6V. I came across this converter design from an LM136 datasheet. Could someone explain the functioning of this circuit.
I can understand that there is the standard buck regulator configuration and a difference amplifier using the npn transistors. The switching functionality eludes me
Best Answer
It appears to be a hysteretic buck regulator. Please see link for more details. Briefly, the switch turns on if the output voltage is lower than the setpoint, and off once the output voltage rises again.
There will be an output voltage oscillation around the setpoint, so this type of regulator is not suitable for applications sensitive to some ripple. It's a cheap solution, and sounds interesting for your application.