Overview
The AD8628ART-REEL7 is a high-precision, single-supply, rail-to-rail input and output operational amplifier produced by Analog Devices Inc. This amplifier is part of the AD8628 family, known for its ultralow offset voltage, drift, and bias current. It features a wide bandwidth and low noise, making it ideal for sensitive measurement applications in harsh operating environments. The AD8628 uses a patented auto-zeroing and chopping topology to maintain low offset voltage over a wide temperature range and throughout its operating lifetime.
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 | 1.5 nA | pA |
| Input Offset Current | IOS | −40°C ≤ TA ≤ +125°C | 50 | 200 | 250 pA | pA |
| Input Voltage Range | 0 | 5 V | V | |||
| Common-Mode Rejection Ratio | CMRR | VCM = 0 V to 5 V | 115 | 130 | 120 dB | dB |
| Large Signal Voltage Gain | AVO | RL = 10 kΩ, VO = 0.3 V to 4.7 V | 110 | 140 | 135 dB | dB |
| Output Voltage High | VOH | RL = 100 kΩ to ground | 4.99 | 4.996 | 4.995 V | V |
| Output Voltage Low | VOL | RL = 100 kΩ to V+ | 1 | 5 mV | 5 mV | mV |
| Short-Circuit Limit | ISC | ±25 | ±50 mA | mA | ||
| Supply Current per Amplifier | ISY | VO = VS/2 | 0.85 | 1.1 mA | 1.2 mA | mA |
Key Features
- Ultralow Offset Voltage: Typically less than 1 µV, ensuring high accuracy in applications requiring low offset errors.
- Low Noise: Features low noise performance, with a voltage noise of 0.5 µV p-p (0 Hz to 10 Hz).
- Rail-to-Rail Input and Output Swing: Allows for full use of the supply voltage range, enhancing the dynamic range of the amplifier.
- High Common-Mode Rejection Ratio (CMRR) and Power Supply Rejection Ratio (PSRR): CMRR of 115 dB to 130 dB and PSRR of 115 dB to 130 dB, ensuring robust performance against common-mode and power supply noise.
- Low Input Bias Current: Typically 100 pA, which is beneficial for high-impedance source applications.
- No External Components Required: The amplifier does not need external capacitors, simplifying the circuit design.
- Fast Overload Recovery Time: Recovery time of 0.05 ms, which is crucial for applications requiring quick response times.
Applications
- Automotive Sensors: Suitable for pressure and position sensors due to its high precision and robustness in harsh environments.
- Strain Gage Amplifiers: Ideal for strain gage applications requiring high accuracy and low noise.
- Medical Instrumentation: Used in medical devices where precision and low noise are critical, such as in thermocouple amplifiers).
- Precision Current Sensing: Suitable for precision current sensing applications due to its low offset voltage and high CMRR).
- Photodiode Amplifier: Used in photodiode amplifier circuits where low noise and high accuracy are necessary).
Q & A
- What is the typical offset voltage of the AD8628?
The typical offset voltage of the AD8628 is less than 1 µV).
- What is the input bias current of the AD8628?
The input bias current is typically 100 pA).
- What is the common-mode rejection ratio (CMRR) of the AD8628?
The CMRR is 115 dB to 130 dB).
- Does the AD8628 require external capacitors?
No, the AD8628 does not require external capacitors).
- What is the supply voltage range for the AD8628?
The AD8628 operates from 2.7 V to 5 V single supply (±1.35 V to ±2.5 V dual supply)).
- What is the slew rate of the AD8628?
The slew rate is 1.0 V/µs).
- What are some common applications of the AD8628?
Common applications include automotive sensors, strain gage amplifiers, medical instrumentation, precision current sensing, and photodiode amplifiers).
- What is the temperature range for the AD8628?
The AD8628 is fully specified from −40°C to +125°C).
- What is the output current limit of the AD8628?
The output current limit is ±30 mA).
- How does the AD8628 reduce digital switching noise?
The AD8628 reduces digital switching noise found in most chopper-stabilized amplifiers through its unique auto-zeroing and chopping topology).
