Overview
The AD8244ARMZ-R7, produced by Analog Devices Inc., is a precision, low-power, FET input, quad unity-gain buffer. This component is designed to isolate very large source impedances from the rest of the signal chain, making it ideal for applications requiring high input impedance and low noise.
The AD8244 is characterized by its unique pinout that physically separates the high impedance inputs from the low impedance supplies and outputs, simplifying guarding and reducing board space. It operates over a wide supply range and is specified over the industrial temperature range of −40°C to +85°C.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Current per Amplifier | 250 | µA |
| Input Bias Current | 2 | pA |
| Input Impedance | 10 TΩ || 4 pF | |
| Voltage Noise at 1 kHz | 13 | nV/√Hz |
| Peak-to-Peak Voltage Noise (0.1 Hz to 10 Hz) | 0.4 | µV |
| Current Noise at 1 kHz | 0.8 | fA/√Hz |
| Offset Drift | 3 | µV/°C |
| Bandwidth | 3 | MHz |
| Slew Rate | 0.8 | V/µs |
| Settling Time to 0.01% | 8 | µs |
| Supply Range (Single Supply) | 3 to 36 | V |
| Supply Range (Dual Supply) | ±1.5 to ±18 | V |
| Operating Temperature Range | −40 to +85 | °C |
Key Features
- Low power consumption: Maximum supply current of 250 µA per amplifier.
- FET input: High input impedance and low input bias current of 2 pA at 25°C.
- Low noise: 13 nV/√Hz voltage noise at 1 kHz and 0.4 µV p-p voltage noise (0.1 Hz to 10 Hz).
- High dc precision: 3 µV/°C maximum offset drift.
- Unique pinout: Physically separates high impedance inputs from low impedance supplies and outputs, simplifying guarding and reducing board space.
- Rail-to-rail output and single-supply operation.
- Wide supply range: Single supply from 3 V to 36 V and dual supply from ±1.5 V to ±18 V.
- Compact 10-lead MSOP package.
Applications
The AD8244 is versatile and can be used in various applications requiring high input impedance and low noise, such as:
- Differential signal chains with minimal error due to close channel-to-channel matching.
- Isolating large source impedances from the rest of the signal chain.
- High precision measurement and instrumentation.
- Audio and medical equipment where low noise and high input impedance are critical.
Q & A
- What is the maximum supply current per amplifier for the AD8244?
The maximum supply current per amplifier is 250 µA.
- What is the input bias current of the AD8244 at 25°C?
The input bias current is 2 pA at 25°C.
- What is the voltage noise of the AD8244 at 1 kHz?
The voltage noise at 1 kHz is 13 nV/√Hz.
- What is the bandwidth of the AD8244?
The bandwidth is 3 MHz.
- What is the slew rate of the AD8244?
The slew rate is 0.8 V/µs.
- What is the operating temperature range of the AD8244?
The operating temperature range is −40°C to +85°C.
- What is the unique feature of the AD8244's pinout?
The unique pinout physically separates the high impedance inputs from the low impedance supplies and outputs, simplifying guarding and reducing board space.
- What are the supply range options for the AD8244?
The AD8244 can operate on a single supply from 3 V to 36 V or a dual supply from ±1.5 V to ±18 V.
- In what package is the AD8244 available?
The AD8244 is available in a compact 10-lead MSOP package.
- What are some typical applications of the AD8244?
Typical applications include differential signal chains, isolating large source impedances, high precision measurement and instrumentation, and audio and medical equipment.
