The Analog Devices 1B21 provides isolated voltage‑to‑current conversion for industrial process‑control applications. It accepts a 0‑1 V to 0‑10 V input and delivers a programmable 4 mA‑20 mA (or 0‑20 mA) output while maintaining 1500 V rms common‑mode isolation and 90 dB CMR.
The device is offered in a small 0.7" × 2.1" × 0.35" DIP package, operates over a wide temperature range (‑25 °C to +85 °C rated, ‑40 °C to +85 °C operating) and requires an external loop supply up to 30 V. Detailed specifications, pin assignments, and application circuits are provided for flexible integration.
| Input Range | 0‑1 V to 0‑10 V |
|---|---|
| Output Current Range | 4 mA to 20 mA (0‑20 mA option) |
| CMV Isolation | 1500 V rms continuous |
| CMR | ≥ 90 dB at 60 Hz |
| Package Size | 0.7" × 2.1" × 0.35" |
| Load Compliance (Vloop = 30 V) | 27 V minimum |
| Rated Temperature Range | ‑25 °C to +85 °C |
| Operating Temperature Range | ‑40 °C to +85 °C |
| Input Bias Current | +30 pA (max +400 pA) |
| Maximum Output Current (overload) | 25 mA |
The 1B21 offers continuous common‑mode voltage isolation of 1500 V rms, meeting IEEE Std. 472 (SWC).
It can be programmed for a 4 mA‑20 mA output, with an optional 0‑20 mA mode.
The device is rated from ‑25 °C to +85 °C and can operate from ‑40 °C to +85 °C.
The package measures 0.7 in × 2.1 in × 0.35 in (0.7" × 2.1" × 0.35").