Overview
The AD8420ARMZ-RL, produced by Analog Devices Inc., is a low-cost, micropower instrumentation amplifier designed for amplifying small differential voltages in the presence of large common-mode signals. It features a novel architecture based on indirect current feedback, which provides an excellent input common-mode range and allows for single-supply operation. The device is optimized for battery-powered applications due to its rail-to-rail output and low power consumption. Available in an 8-lead Mini Small Outline Package (MSOP), the AD8420 operates over a temperature range of -40°C to +85°C and is functional from -40°C to +125°C.
Key Specifications
| Parameter | Value | Conditions |
|---|---|---|
| Gain Range | 1 to 1000 V/V | G = 1 + (R2/R1) |
| Gain Error | 0.02% (G = 1), 0.05% to 0.1% (G = 10 to 1000) | VOUT = 0.1 V to 1.1 V, VREF = 0.1 V; VOUT = 0.2 V to 4.8 V |
| Gain vs. Temperature | 10 ppm/°C | TA = -40°C to +85°C |
| Output Swing | -VS + 100 mV to +VS - 150 mV | VS = 5 V, RL = 10 kΩ to midsupply |
| Supply Voltage Range | 3 V to ±5 V | |
| Supply Current | 90 μA (max) | |
| Operating Temperature Range | -40°C to +85°C | |
| Package Type | 8-Lead MSOP |
Key Features
- Rail-to-rail output stage maximizing dynamic range in low supply voltage operations.
- Single-supply operation with the ability to amplify signals at or below ground without requiring dual supplies.
- Low power consumption (micropower) making it ideal for battery-powered applications.
- Excellent input common-mode range due to indirect current feedback architecture.
- Low drift characteristics and high gain accuracy.
- Operational from -40°C to +125°C with specified performance over -40°C to +85°C.
Applications
- Medical instrumentation: Suitable for applications requiring low power and high accuracy in medical devices.
- Industrial instrumentation: Ideal for various industrial applications due to its robust performance and low power consumption.
- Battery-powered devices: Optimized for use in battery-powered systems where low power consumption is critical.
- 4 mA to 20 mA current loop interfaces: Can be used to interface signals from 4 mA to 20 mA transducers with high accuracy and low offset errors.
Q & A
- What is the gain range of the AD8420? The gain range of the AD8420 is from 1 to 1000 V/V, set by the external resistors R1 and R2.
- What is the output swing of the AD8420? The output swing is from -VS + 100 mV to +VS - 150 mV.
- Can the AD8420 operate on a single supply? Yes, the AD8420 can operate on a single supply and can amplify signals at or below ground without requiring dual supplies.
- What is the maximum supply current of the AD8420? The maximum supply current is 90 μA.
- What is the operating temperature range of the AD8420? The specified performance temperature range is -40°C to +85°C, and it is operational from -40°C to +125°C.
- In what package is the AD8420 available? The AD8420 is available in an 8-lead Mini Small Outline Package (MSOP).
- Is the AD8420 suitable for battery-powered applications? Yes, it is optimized for battery-powered applications due to its low power consumption and rail-to-rail output.
- Can the AD8420 be used in 4 mA to 20 mA current loop interfaces? Yes, it is a good candidate for use in 4 mA to 20 mA current loop interfaces due to its low drift characteristics and ability to sense differential currents accurately.
- What is the gain error of the AD8420? The gain error is 0.02% for G = 1 and 0.05% to 0.1% for G = 10 to 1000.
- How does the AD8420 handle common-mode signals? The AD8420 has an excellent input common-mode range due to its indirect current feedback architecture, allowing it to handle large common-mode signals effectively.
