The AD736BRZ-R7 can compute the rms value of both ac and dc input voltages. It can also be operated as an ac-coupled device by adding one external capacitor. In this mode, the AD736BRZ-R7 can resolve input signal levels of 100 μV rms or less, despite variations in temperature or supply voltage. High accuracy is also maintained for input waveforms with crest factors of 1 to 3. In addition, crest factors as high as 5 can be measured (introducing only 2.5% additional error) at the 200 mV full-scale input level.
The AD736BRZ-R7 has its own output buffer amplifier, thereby pro-viding a great deal of design flexibility. Requiring only 200 μA of power supply current, the AD736BRZ-R7 is optimized for use in portable multimeters and other battery-powered applications.
The AD736BRZ-R7 allows the choice of two signal input terminals: a high impedance FET input (1012 Ω) that directly interfaces with High-Z input attenuators and a low impedance input (8 kΩ) that allows the measurement of 300 mV input levels while operating from the minimum power supply voltage of +2.8 V, −3.2 V. The two inputs can be used either single ended or differentially.
The AD736BRZ-R7 has a 1% reading error bandwidth that exceeds 10 kHz for the input amplitudes from 20 mV rms to 200 mV rms while consuming only 1 mW.
The AD736BRZ-R7 is available in four performance grades. The AD736J and AD736K grades are rated over the 0°C to +70°C and −20°C to +85°C commercial temperature ranges. The AD736A and AD736B grades are rated over the −40°C to +85°C industrial temperature range. The AD736BRZ-R7 is available in three low cost, 8-lead packages: PDIP, SOIC, and CERDIP.
Product Highlights
Data Sheet, Rev. I, 12/12
Feature
- Converts an ac voltage waveform to a dc voltage and then converts to the true rms, average rectified, or absolute value 200 mV rms full-scale input range (larger inputs with input attenuator)
- High input impedance: 1012 Ω
- Low input bias current: 25 pA maximum
- High accuracy: ±0.3 mV ± 0.3% of reading
- RMS conversion with signal crest factors up to 5
- Wide power supply range: +2.8 V, −3.2 V to ±16.5 V
- Low power: 200 μA maximum supply current
- Buffered voltage output
- No external trims needed for specified accuracy
- Related device: thefeatures a power-down control with standby current of only 25 μA; the dc output voltage is negative and the output impedance is 8 kΩ
(Picture: Pinout)
