Overview
The AD8628AR, produced by Analog Devices Inc., is a high-performance, zero-drift, single-supply operational amplifier. This amplifier is part of the AD8628/AD8629/AD8630 family, known for their wide bandwidth, rail-to-rail input and output swing, and exceptionally low noise. The AD8628AR is designed to offer high accuracy and low noise, making it suitable for applications requiring high dc precision.
It operates fully specified from 2.7 V to 5 V single supply (±1.35 V to ±2.5 V dual supply), and it combines the benefits of auto-zeroing and chopper-stabilized amplifiers at a lower cost. The amplifier features an ultralow offset voltage of 1 µV, a drift of less than 0.005 µV/°C, and low noise of 0.5 µV p-p (0 Hz to 10 Hz).
Key Specifications
| Parameter | Symbol | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|---|
| Offset Voltage | VOS | −40°C ≤ TA ≤ +125°C | 1 | 5 | 10 | µV |
| Input Bias Current | IB | −40°C ≤ TA ≤ +125°C | 30 | 100 | 300 | pA |
| Input Offset Current | IOS | −40°C ≤ TA ≤ +125°C | 50 | 200 | 250 | pA |
| Input Voltage Range | 0 | 5 | V | |||
| Common-Mode Rejection Ratio | CMRR | VCM = 0 V to 2.7 V | 110 | 130 | dB | |
| Large Signal Voltage Gain | AVO | RL = 10 kΩ, VO = 0.3 V to 2.4 V | 110 | 140 | dB | |
| Power Supply Rejection Ratio | PSRR | VS = 2.7 V to 5.5 V | 110 | 130 | dB | |
| Supply Current/Amplifier | ISY | VO = 0 V | 0.75 | 1.0 | 1.2 | mA |
| Slew Rate | SR | RL = 10 kΩ | 1.0 | V/µs | ||
| Overload Recovery Time | 0.05 | ms | ||||
| Gain Bandwidth Product | GBP | 2.5 | MHz | |||
| Voltage Noise Density | en | f = 1 kHz | 22 | nV/√Hz | ||
| Current Noise Density | in | f = 10 Hz | 5 | fA/√Hz |
Key Features
- Ultralow Offset and Drift: The AD8628AR features an offset voltage of 1 µV and a drift of less than 0.005 µV/°C, ensuring high accuracy in precision applications.
- Rail-to-Rail Input and Output Swing: The amplifier can operate with input and output voltages that range from the negative supply rail to the positive supply rail, enhancing its versatility.
- Low Noise: With a voltage noise of 0.5 µV p-p (0 Hz to 10 Hz) and a voltage noise density of 22 nV/√Hz at 1 kHz, this amplifier is ideal for low-noise applications.
- High Gain and CMRR/PSRR: The AD8628AR offers high gain (110 dB to 140 dB), common-mode rejection ratio (CMRR) of 110 dB to 130 dB, and power supply rejection ratio (PSRR) of 110 dB to 130 dB.
- Low Input Bias Current: The input bias current is as low as 30 pA to 100 pA, making it suitable for applications where low input current is critical.
- No External Components Required: The amplifier does not require any external components, simplifying the design and reducing the overall cost.
- Automotive and Industrial Qualification: The AD8628AR is qualified for automotive and industrial applications, ensuring reliability in harsh environments.
Applications
- Automotive Sensors: Suitable for pressure, position, and strain gage sensors in automotive systems.
- Medical Instrumentation: Used in medical devices requiring high precision, such as thermocouple amplifiers and photodiode amplifiers.
- Precision Current Sensing: Ideal for precision current sensing applications due to its low noise and high accuracy.
- Infrared Sensors: Can be used in infrared sensor circuits where low noise and high precision are necessary.
- High Precision DACs: Suitable as output amplifiers for high precision digital-to-analog converters (DACs).
Q & A
- What is the typical offset voltage of the AD8628AR?
The typical offset voltage of the AD8628AR is 1 µV.
- What is the input bias current range of the AD8628AR?
The input bias current range is from 30 pA to 100 pA.
- What is the common-mode rejection ratio (CMRR) of the AD8628AR?
The CMRR is between 110 dB and 130 dB.
- What is the slew rate of the AD8628AR?
The slew rate is 1.0 V/µs.
- Does the AD8628AR require any external components?
No, the AD8628AR does not require any external components.
- What are the typical supply current requirements for the AD8628AR?
The typical supply current is 1.0 mA.
- What is the gain bandwidth product (GBP) of the AD8628AR?
The GBP is 2.5 MHz.
- What are the operating temperature ranges for the AD8628AR?
The operating temperature range is from -40°C to +125°C.
- Is the AD8628AR qualified for automotive applications?
Yes, the AD8628AR is qualified for automotive applications.
- What is the voltage noise density of the AD8628AR at 1 kHz?
The voltage noise density at 1 kHz is 22 nV/√Hz.
