Tiny Switching Regulators Deliver Digitally-Controlled Output Voltages

Through use of an on-chip "electric volume" feature, the S-8330 Series of miniature switching regulators can deliver digitally-controlled output voltages ranging from 8V to 30V over a wide, 2V-to-9V input voltage range. Output voltages can be adjusted with an 8-bit digital signal from a µP or other control unit, with the adjustment feature qualifying the S-8330 regulators for use as bias generators for LCD graphic (dot matrix) displays-- the bias voltage is adjusted to change the display's contrast.
The CMOS PWM-control step-up switching regulators consist of a reference voltage source, an oscillation circuit, a power MOSFET, and an error amplifier. To implement the above voltage adjustment feature using S-8330 devices, only a coil, capacitor and diode are required. The regulators cost $1.70 each/2,000.