Overview
The ADA4940-2ACPZ-RL, produced by Analog Devices Inc., is a low noise, low distortion fully differential amplifier. It is designed to operate with very low power consumption, making it an ideal choice for driving low power, high resolution, and high performance SAR (Successive Approximation Register) and Σ-Δ (Sigma-Delta) analog-to-digital converters (ADCs). The amplifier is fabricated using Analog Devices' SiGe complementary bipolar process, which enables it to achieve very low levels of distortion and high dynamic performance.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Operating Voltage Range | 3 | - | 7 | V |
| Quiescent Current per Amplifier (Enabled) | 1.05 | 1.25 | 1.38 | mA |
| Quiescent Current per Amplifier (Disabled) | 13.5 | - | 28.5 | µA |
| Input Bias Current | -1.6 | -1.1 | - | µA |
| Input Offset Current | -500 | - | 500 | nA |
| Input Common-Mode Voltage Range | -VS - 0.2 | - | +VS - 1.2 | V |
| Input Resistance (Differential) | - | 33 | - | kΩ |
| Input Resistance (Common Mode) | - | 50 | - | MΩ |
| Input Capacitance | - | 1 | - | pF |
| Common-Mode Rejection Ratio (CMRR) | 86 | - | 119 | dB |
| Open-Loop Gain | 91 | - | 99 | dB |
| Output Voltage Swing (Single-Ended) | -VS + 0.1 | - | +VS - 0.1 | V |
| Output Balance Error | -65 | - | -60 | dB |
| Operating Temperature Range | -40 | - | 125 | °C |
Key Features
- Low Noise and Distortion: The ADA4940-2 features very low noise and distortion, making it suitable for high-performance applications.
- Low Power Consumption: Operates on a quiescent current of only 1.25 mA per amplifier.
- Adjustable Output Common-Mode Voltage: Allows matching the input common-mode voltage of multiple ADCs.
- Flexible Power Supplies: Can operate from 3 V to 7 V.
- Disable Pin: Reduces power consumption when disabled.
- High Dynamic Performance: Suitable for driving SAR and Σ-Δ ADCs with resolutions up to 18 bits.
- Internal Common-Mode Feedback Loop: Provides exceptional output balance and suppression of even-order harmonic distortion products.
Applications
- Low Power ADC Drivers: Ideal for driving low power, high resolution SAR and Σ-Δ ADCs.
- Single-Ended-to-Differential Conversion: Converts single-ended signals to differential signals.
- Differential Buffers and Line Drivers: Used in various signal processing and transmission applications.
- Medical Imaging: Suitable for medical imaging equipment due to its low noise and high dynamic performance.
- Industrial Process Controls: Used in industrial automation and control systems.
- Portable Electronics: Ideal for battery-powered devices requiring low power consumption.
Q & A
- What is the operating voltage range of the ADA4940-2?
The ADA4940-2 operates from 3 V to 7 V. - How much quiescent current does the ADA4940-2 consume when enabled?
The quiescent current per amplifier when enabled is typically 1.25 mA. - What is the input common-mode voltage range of the ADA4940-2?
The input common-mode voltage range is from -VS - 0.2 V to +VS - 1.2 V. - What is the common-mode rejection ratio (CMRR) of the ADA4940-2?
The CMRR is typically 86 dB to 119 dB. - Can the ADA4940-2 be used in medical imaging applications?
Yes, it is suitable for medical imaging due to its low noise and high dynamic performance. - How does the disable pin function on the ADA4940-2?
The disable pin reduces power consumption when the amplifier is disabled, with a turn-off time of 10 µs and a turn-on time of 0.6 µs. - What is the operating temperature range of the ADA4940-2?
The operating temperature range is from -40°C to +125°C. - What types of ADCs can the ADA4940-2 drive?
The ADA4940-2 can drive SAR and Σ-Δ ADCs with resolutions up to 18 bits. - What is the typical output balance error of the ADA4940-2?
The output balance error is typically -65 dB to -60 dB. - What package options are available for the ADA4940-2?
The ADA4940-2 is available in a Pb-free, 24-lead LFCSP package.
