The AD654 is a low-cost monolithic voltage-to-frequency converter that features single or dual supply, 5 V to 36 V, -5 V to -18 V, full-scale frequency up to 500 kHz.
The AD654 converts an input voltage or current to a frequency‑output using a precision oscillator and a high‑current output stage. It operates from a single 5 V to 36 V supply, draws only 2 mA quiescent current, and can drive up to 12 TTL loads or optocouplers.
The device is offered in 8‑lead mini‑DIP and SOIC packages, requires only a single RC timing network for full‑scale frequency setting, and includes an open‑collector output capable of sinking more than 10 mA. Detailed specifications, absolute maximum ratings, and application circuits are provided.
| Full‑Scale Frequency Range | 0 to 500 kHz |
|---|---|
| Quiescent Current (5 V supply) | 1.5 – 2.5 mA |
| Input Resistance (Non‑inverting) | 250 MΩ |
| Input Offset Voltage | 0.5 – 1.0 mV |
The device draws about 2.0 mA quiescent current, ranging from 1.5 mA at 5 V to 2.5 mA at 30 V.
It can generate frequencies up to 500 kHz at full scale.