Overview
The AD736AQ, produced by Analog Devices Inc., is a low power, precision, monolithic true rms-to-dc converter. It is designed to provide high accuracy in measuring a wide range of input waveforms, including sine waves, variable duty-cycle pulses, and triac (phase)-controlled sine waves. The AD736AQ is laser trimmed to ensure a maximum error of ±0.3 mV ± 0.3% of reading with sine wave inputs, making it suitable for upgrading the performance of non-rms precision rectifiers in various applications.
Key Specifications
| Parameter | Value |
|---|---|
| Input Range | 200 mV rms full-scale (larger inputs with input attenuator) |
| Input Impedance | High Impedance: 10-12 Ω FET input, Low Impedance: 8 kΩ |
| Input Bias Current | 25 pA maximum |
| Accuracy | ±0.3 mV ± 0.3% of reading |
| Power Supply Range | +2.8 V, -3.2 V to ±16.5 V |
| Power Consumption | 200 µA maximum supply current, 1 mW |
| Operating Temperature Range | –40°C to +85°C (AD736AQ grade) |
| Package Types | Plastic mini-DIP, Plastic SOIC, Hermetic CERDIP |
| Bandwidth | 1% reading error bandwidth exceeding 10 kHz for input amplitudes from 20 mV rms to 200 mV rms |
Key Features
- Computes true rms value, average rectified value, or absolute value of various input signals.
- Requires only one external component, an averaging capacitor, for true rms measurement.
- Low power consumption of 1 mW, making it suitable for battery-powered applications.
- High input impedance of 10-12 Ω eliminates the need for an external buffer when interfacing with input attenuators.
- A low impedance input is available for measuring up to 300 mV rms input signals while operating from low power supply voltages.
- Buffered voltage output with no external trims needed for specified accuracy.
Applications
The AD736AQ is optimized for use in portable multimeters and other battery-powered applications. It is also suitable for upgrading the performance of non-rms precision rectifiers in various applications, including those requiring high accuracy measurements of ac and dc input voltages.
Q & A
- What is the primary function of the AD736AQ? The AD736AQ is a true rms-to-dc converter that computes the rms value, average rectified value, or absolute value of various input signals.
- What is the maximum error of the AD736AQ with sine wave inputs? The AD736AQ has a maximum error of ±0.3 mV ± 0.3% of reading with sine wave inputs.
- What are the input impedance options for the AD736AQ? The AD736AQ offers two input impedance options: a high impedance FET input (10-12 Ω) and a low impedance input (8 kΩ).
- How much power does the AD736AQ consume? The AD736AQ consumes a maximum of 200 µA of power supply current and 1 mW of power.
- What is the operating temperature range for the AD736AQ? The AD736AQ operates over an industrial temperature range of –40°C to +85°C.
- What packages is the AD736AQ available in? The AD736AQ is available in plastic mini-DIP, plastic SOIC, and hermetic CERDIP packages.
- Can the AD736AQ measure high crest factor signals? Yes, the AD736AQ can measure input waveforms with crest factors up to 5, introducing only 2.5% additional error at the 200 mV full-scale input level.
- How does the AD736AQ handle ac-coupled inputs? The AD736AQ can be operated as an ac-coupled device by adding one external capacitor, allowing it to resolve input signal levels of 100 µV rms or less.
- What is the bandwidth of the AD736AQ? The AD736AQ achieves a 1% reading error bandwidth exceeding 10 kHz for input amplitudes from 20 mV rms to 200 mV rms.
- Is an external buffer required for the AD736AQ when using high impedance inputs? No, the high input impedance of the AD736AQ eliminates the need for an external buffer when interfacing with input attenuators.
