The AP4830 provides a DC output that can be programed to ramp up or down to a setpoint by supplying 0-5VDC to the Setpoint Control (pin 6) and the Ramp Rate Control (pin 10) inputs.

An external potentiometer, typically 10KΩor greater, may be used to attenuate the built-in +5V reference and provide intermediate setpoint and rate values (see Figure 1). Use a rotary switch or relay to select multiple potentiometers for different setpoint and rate selections. To ‘hold’ the output ramp indefinitely, disconnect the Setpoint Control input (pin 6).

The AP4830 may require an external timing capacitor to set the ramp base rate. Use one of the supplied capacitors or any polarized electrolytic or tantalum capacitor. An external contact closure from pin (13) to pin (15) or a +5V level to pin (15) will immediately reset the output to minimum. The setpoint status is an open collector output (pin 5) which will sink up to 20mA when the ramp reaches the setpoint.