RMS-to-DC converter measures low signal levels with high accuracy
8/17/2011 9:13 AM EDT
Analog Devices Inc. unveiled an integrated true RMS-to-DC converter that offers a 100 µV to 3 V of usable dynamic range and the ability to measure extremely low signal levels with high accuracy and no drop in settling time.
The AD8436 precision monolithic true RMS-to-DC converter features AC conversion accuracy to better than ± 0.5 percent. Uniform settling for widely variant input values enables consistent conversion rates with results displayed promptly for near-zero and high-level AC inputs. The AD8436 is immune to temperature, crest factor and supply voltage variations. Zero DC offset voltages at the converter output simplify calibration. This performance is packed into a compact 4 mm x 4 mm package integrated with a FET input and precision DC buffer amplifiers and consumes 300 μA of power.
The AD8436 is suitable for remote, portable battery-powered instrumentation, energy and automotive applications where limited board space and outdoor environments are considerations.
- Instantly computes true RMS value
- Fast and constant settling time at all input levels
- Wide usable dynamic range: 100 μV RMS to 3 VRMS (8.5 V p-p) full-scale
- Input frequency range: 65 kHz for additional 1 percent error
- Low power: 300 µA typical at ±2.4 V
- Accuracy: ±10 μV ± 0.5 percent of reading max
- System-on-a-chip includes FET input buffer with precision gain setting resistors, output buffer
- Supply range:
- Dual: +/-2.4 V to +/-18 V
- Single: 4.8 V to 36 V
Pricing: The AD8436A with a -40˚C to 125˚C temperature range is priced at $4.95 each, while the AD8436J with a 0˚C to 70˚C temperature range is priced at $2.95 in 1k unit quantities. Both are available in a 20-lead LFCSP 4mm x 4mm package.
Availability: Full volume production.
Datasheet: Click here.