VFC100

The VFC100 voltage-to-frequency converter is an important advance in VFCs. The well-proven charge balance technique is used; however, the critical reset integration period is derived from an external clock frequency. The external clock accurately sets an output full-scale frequency, eliminating error and drift from the external timing components required for other VFCs. A precision input resistor is provided which accurately sets a 10V full-scale input voltage. In many applications the required accuracy can be achieved without external adjustment.

The VFC100 open collector active-low output provides fast fall time on the important leading edge of output pulses,and interfaces easily with TTL and CMOS circuitry. An output one-shot circuit of VFC100  is particularly useful to provide optimum output pulse widths for optical couplers and transformers to achieve voltage isolation. An
accurate 5V reference is also provided which is useful for applications such as offsetting for bipolar input voltages, exciting bridges and sensors, and autocalibration schemes.