Overview
The AD636JDZ, produced by Analog Devices Inc., is a low power monolithic IC designed for true RMS-to-DC conversion of low-level signals. It offers performance comparable or superior to that of hybrid and modular converters, but at a lower cost. The device is optimized for battery-powered portable instruments due to its low power supply current requirement of typically 800 μA. It operates from a wide range of dual and single power supplies, from ±2.5 V to ±16.5 V or from +5 V to +24 V. The AD636JDZ is factory-trimmed at the wafer level for input and output offset, positive and negative waveform symmetry, and full-scale accuracy, eliminating the need for external trims.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Input Signal Range | 0 | - | 200 | mV rms |
| Bandwidth (−3 dB) | - | 1.5 | - | MHz (at 200 mV rms) |
| Crest Factor | - | - | 6 | - |
| Power Supply Current | - | 800 | - | μA |
| Power Supply Range (Dual) | ±2.5 | - | ±16.5 | V |
| Power Supply Range (Single) | 5 | - | 24 | V |
| Total Error (AD636J) | - | ±0.5 mV ± 1.0% of reading | - | - |
| Total Error (AD636K) | - | ±0.2 mV to ±0.5% of reading | - | - |
| Operating Temperature | 0 | - | 70 | °C |
| Package Type | - | 14-Lead Side Brazed CerDIP | - | - |
Key Features
- True RMS-to-DC conversion for ac and dc signals with a bandwidth of up to 1 MHz for signals greater than 100 mV rms.
- Low power consumption with a quiescent current of typically 800 μA, making it suitable for battery-powered instruments.
- Wide power supply range: ±2.5 V to ±16.5 V or +5 V to +24 V.
- Input and output terminals are fully protected, allowing input signals to exceed the power supply without damage to the device.
- Auxiliary dB output derived from an internal circuit point, representing the logarithm of the rms output.
- Optional on-chip amplifier for input or output buffering, sourcing up to 5 mA.
- No external trims required due to factory trimming at the wafer level for input and output offset, waveform symmetry, and full-scale accuracy.
Applications
- Battery-powered portable instruments due to its low power consumption.
- Measurement of complex input waveforms with crest factors up to 6.
- Use in display-oriented ADCs due to its 200 mV full-scale range compatibility.
- Audio and signal processing applications requiring accurate RMS measurements.
Q & A
- What is the primary function of the AD636JDZ?
The AD636JDZ performs true RMS-to-DC conversion on low-level signals, including both ac and dc inputs.
- What is the typical power supply current of the AD636JDZ?
The typical power supply current is 800 μA, making it suitable for battery-powered devices.
- What is the operating temperature range of the AD636JDZ?
The device operates between 0°C and 70°C.
- What types of power supplies can the AD636JDZ operate from?
The AD636JDZ can operate from dual power supplies (±2.5 V to ±16.5 V) or single power supplies (+5 V to +24 V).
- Does the AD636JDZ require external trims for accuracy?
No, the device is factory-trimmed at the wafer level, eliminating the need for external trims.
- What is the maximum crest factor the AD636JDZ can accommodate?
The AD636JDZ can accommodate crest factors up to 6 with less than 0.5% additional error.
- What is the purpose of the auxiliary dB output?
The auxiliary dB output represents the logarithm of the rms output and can be set to correspond to any input level from 0 dBm to −20 dBm.
- What is the bandwidth of the AD636JDZ at 200 mV rms input?
The bandwidth at 200 mV rms input is up to 1.5 MHz.
- Is the AD636JDZ protected against input signals exceeding the power supply voltage?
- What is the maximum current the on-chip amplifier can source?
The on-chip amplifier can source up to 5 mA.
