Overview
The AD628ARZ, produced by Analog Devices Inc., is a high common-mode voltage, programmable gain difference amplifier. This device is designed to provide excellent DC performance and high common-mode rejection over a wide range of frequencies. It is particularly suited for high voltage measurements and applications where large differential input signals need to be accurately scaled and processed.
The AD628ARZ operates from single and dual supplies, making it versatile for various system configurations. It is available in 8-lead SOIC_N and 8-lead MSOP packages and operates over the standard industrial temperature range of -40°C to +85°C.
Key Specifications
| Parameter | Value | Conditions |
|---|---|---|
| Input Common-Mode Voltage Range | ±120 V | VS = ±15 V |
| Differential Mode Voltage Range | ±120 V | VS = ±15 V |
| System Gain | Fixed at 0.1 (input stage), adjustable (output buffer) | GA2 = 1 + REXT1/REXT2 |
| Input Bias Current | 2 nA (max) | |
| Supply Voltage Range | Single and dual supplies | |
| Operating Temperature Range | -40°C to +85°C | |
| Package Types | 8-lead SOIC_N, 8-lead MSOP |
Key Features
- High Common-Mode Input Voltage Range: The AD628ARZ can handle input common-mode voltages up to ±120 V, making it suitable for high voltage measurements.
- Programmable Gain: The output buffer gain is user-adjustable using external resistors, allowing for flexible system design.
- Low Input Bias Current: The input bias current of the buffer amplifier is very low, minimizing offset voltage effects.
- Integrated Low-Pass Filter: A precision 10 kΩ resistor is provided for implementing a low-pass filter or attenuating large differential input signals.
- Kelvin Connection: The inverting input of the buffer amplifier is available for making a remote Kelvin connection, enhancing measurement accuracy.
Applications
- High Voltage Measurements: Ideal for measuring voltages across shunt resistors in high voltage systems.
- Battery Monitoring: Suitable for monitoring battery voltages in chargers and other power supply applications.
- Current Loop Conversion: Easily converts current-loop signals to voltage-driven signals for single-supply ADCs.
- Power Line Monitoring: Attenuates and shifts differential input signals, protecting against destructive voltage peaks and surges.
Q & A
- What is the input common-mode voltage range of the AD628ARZ?
The input common-mode voltage range is ±120 V at VS = ±15 V.
- How is the system gain of the AD628ARZ adjusted?
The system gain is adjusted using external resistors REXT1 and REXT2, with the gain formula GA2 = 1 + REXT1/REXT2.
- What is the input bias current of the buffer amplifier?
The input bias current of the buffer amplifier is 2 nA (max).
- What are the available package types for the AD628ARZ?
The AD628ARZ is available in 8-lead SOIC_N and 8-lead MSOP packages.
- What is the operating temperature range of the AD628ARZ?
The operating temperature range is -40°C to +85°C.
- Can the AD628ARZ be used for high voltage measurements?
Yes, it is designed for high voltage measurements and can handle voltages up to ±120 V.
- How does the AD628ARZ protect against voltage peaks and surges?
The AD628ARZ attenuates and shifts differential input signals, protecting against destructive voltage peaks and surges.
- Can the AD628ARZ be used in battery monitoring applications?
Yes, it is suitable for monitoring battery voltages in chargers and other power supply applications.
- How is the low-pass filter implemented in the AD628ARZ?
A precision 10 kΩ resistor is provided for implementing a low-pass filter or attenuating large differential input signals.
- What is the purpose of the Kelvin connection in the AD628ARZ?
The Kelvin connection allows for remote measurement, enhancing measurement accuracy by compensating for lead resistance.
