## Overview of the AD737JRZ-5-R7 The **AD737JRZ-5-R7** is a high-precision, low-power, monolithic **True RMS-to-DC Converter**. It is designed to compute the root-mean-square value of both AC and DC input signals with high accuracy. --- ### 1. Key Technical Specifications The following table summarizes the primary electrical characteristics of the AD737JRZ-5-R7: | Parameter | Specification | | :--- | :--- | | **Manufacturer** | Analog Devices Inc. | | **Function** | True RMS-to-DC Converter | | **Operating Supply Voltage** | ±2.5 V to ±16.5 V (Dual) or +5 V to +33 V (Single) | | **Supply Current** | 160 µA (Typical) | | **Package Type** | SOIC-8 (Narrow Body) | | **Accuracy** | ±0.2 mV ± 0.3% of Reading | | **Bandwidth** | 190 kHz (at 200 mV rms) | | **Input Impedance** | 10¹² Ω (High Z input) | --- ### 2. Functional Components and Features The AD737 series is unique because of its internal architecture, which consists of four main subsections: 1. **Input Amplifier:** Provides a high-impedance input stage to prevent loading of the source signal. 2. **Absolute Value Circuit (Rectifier):** Converts the input signal into its absolute value. 3. **Squaring/Divider Circuit:** Performs the core mathematical computation ($V_{out} = \text{Avg}[V_{in}^2 / V_{out}]$). 4. **Averaging Filter:** An external capacitor ($C_{AV}$) is used to determine the averaging time constant and low-frequency accuracy. #### Key Features: * **True RMS Measurement:** Unlike "average responding" rectifiers, this part accurately measures complex waveforms, including square waves, pulse trains, and SCR waveforms. * **Low Power:** Ideal for battery-powered handheld instruments (Multimeters). * **Buffered Output:** Provides a low-impedance output for driving ADCs or other circuits. --- ### 3. Pin Configuration (SOIC-8) | Pin No. | Name | Description | | :--- | :--- | :--- | | 1 | **-V_S** | Negative Supply Voltage | | 2 | **Input** | Signal Input (High Impedance) | | 3 | **COM** | Common/Reference Ground | | 4 | **Output** | DC Output Voltage | | 5 | **C_AV** | Averaging Capacitor Connection | | 6 | **+V_S** | Positive Supply Voltage | | 7 | **NC** | No Connection | | 8 | **BUF IN** | Buffer Input for output stage | --- ### 4. Typical Application Circuit To use the AD737, you generally need minimal external components. Below is a simplified representation of the connection logic: ```c // Connection Logic Diagram [Input Signal] ----> Pin 2 (Input) | [C_AV Capacitor] ----> Pin 5 (Averaging) | [Power Supply] ----> Pin 1 (-Vs) & Pin 6 (+Vs) | [DC Output] <---- Pin 4 (RMS Voltage Out) ``` --- ### 5. Packaging and Suffix Meanings * **AD737**: Part number base. * **J**: Accuracy/Performance grade (Standard). * **R**: Package style (SOIC). * **Z**: RoHS compliant (Lead-free). * **5**: 5-inch reel size (though often refers to specific voltage trimming in some contexts, here it aligns with internal silicon revisions). * **R7**: Tape and Reel packaging (7-inch reel).