The AD688 is a high precision ±10 V tracking reference. Low tracking error, low initial error, and low temperature drift give the AD688 reference absolute ±10 V accuracy performance previously unavailable in monolithic form. The AD688 uses a proprietary ion-implanted buried Zener diode, and laser wafer drift trimming of high stability thin-film resistors to provide outstanding performance. The AD688 includes the basic reference cell and three additional amplifiers. The amplifiers are laser-trimmed for low offset and low drift.
The AD688 provides a high‑precision +10 V tracking reference with Kelvin‑force and Kelvin‑sense outputs. It uses a proprietary ion‑implanted buried Zener diode and laser‑trimmed thin‑film resistors to achieve low tracking error, low initial error, and low temperature drift.
The device includes gain and balance adjustment pins for fine trimming, optional noise‑reduction circuitry, and short‑circuit‑protected outputs. It is offered in 16‑lead SOIC and CERDIP packages and operates over a –40 °C to +85 °C temperature range.
| Tracking error | ≤ 1.5 mV |
|---|---|
| Temperature drift | 1.5 ppm/°C |
| Output noise (0.1 Hz‑10 Hz) | ≈ 6 µV p‑p |
| Supply voltage rating | ±18 V (36 V total) |
| Turn‑on settling time (no external cap) | ≈ 600 µs |
| Turn‑on settling time (1 µF cap) | ≈ 100 ms |
The tracking error is less than 1.5 mV.
Typical output noise is about 6 µV peak‑to‑peak over the 0.1 Hz‑10 Hz band.
The device is rated for a total supply voltage of 36 V (±18 V).
Without an external noise‑reduction capacitor the turn‑on settling time is about 600 µs; with a 1 µF capacitor it is roughly 100 ms.