PWM CONTROL 3A STEP-DOWN CONVERTER
UTC P1786 consists of 3A step-down switching regulator control
which includes a reference voltage source, oscillation circuit, error
amplifier, internal PMOS and etc with PWM.
UTC P1786 can provide low-ripple power, high efficiency, and
excellent transient characteristics. An enable function, an over
current protect and short circuit protect function are built inside, so
the operation frequency can be reduced from 300KHz to 30KHz
when OCP or SCP happens. The PWM control circuit can vary the
duty ratio linearly from 100 down to 0%. This converter also includes
an error amplifier circuit as well as a soft-start circuit that prevents
overshoot at startup. Also, to minimum external component counts
for an internal compensation block is built in.
These ICs can work as step-down switching regulators with the
addition of an internal P-channel Power MOS, a coil, capacitors, and
a diode connected externally. They provide such outstanding
features: low current consumption. It is also suitable for the
operation via an AC adapter because this converter accommodate an input voltage up to 23V.
* Input voltage: 4.0V ~ 23V
* Output voltage: 0.8V ~ VCC
* Duty ratio: 0% to 100% PWM control
* Oscillation frequency: 300KHz typ.
* Soft-start, current limit, enable function
* Thermal shutdown function
* Built-in internal SW P-channel MOS