With low DC offset, dc offset drift and excellent dynamic performance, the ADA4945-1 is ideal for a wide range of data acquisition and signal processing applications. The device is ideal for driving high resolution, high performance successive approximation registers (SAR) and sigma-delta analog-to-digital converters (ADCs) at 4 mA quiescent current (full power mode). The device also has the option of operating at 1.4 mA quiescent current (low power mode) to reduce power consumption to the performance required for ADC drive applications. The adjustable common-mode voltage allows the ADA4945-1 to match the input common-mode voltage of multiple ADCs. The internal common-mode feedback loop provides excellent output balance and rejects even-order harmonic distortion products.

Using the ADA4945-1, a differential gain configuration is implemented through a simple external feedback network that determines the closed-loop gain of the amplifier with four resistors. The ADA4945-1 is fabricated using Analog Devices' proprietary silicon germanium (SiGe) complementary bipolar process, which enables low distortion and input voltage noise of only 1.8 nV / √ Hz (full power mode).

The ADA4945-1 is available in a RoHS-compliant, 3 mm × 3 mm, 16-lead LFCSP package. The ADA4945-1 is rated for operation over the -40°C to +125°C temperature range.

Drawing/package

main feature

- Wide power supply range: 3 V to 10 V
- Wide input common mode voltage range: -V S to + V S - 1.3 V
- Rail-to-rail output
- Fully specified dual power mode operation
         - 4 mA full power mode (145 MHz)
         - 1.4 mA low power mode (80 MHz)
- Full power mode
         - Low harmonic distortion
         - -133 dBc HD2 and -140 dBc HD3 at 1 kHz
         - -133 dBc HD2 and -116 dBc HD3 at 100 kHz
- Quick set up time
         - 18 digits: 100 ns
         - 16 digits: 50 ns
- Input voltage noise: 1.8 nV / √ Hz, f = 100 kHz
- Maximum offset voltage from -40°C to +125°C is ±115μV
- Adjustable output clamp for ADC input protection

General application

- Low power Σ-Δ, PulSAR® and SAR ADC drivers
- Single-ended to differential converter
- Differential buffer
- Medical imaging
- Process control
- Portable electronic devices

Yes - The ADA4945-1 can be evaluated using the ADA4945-1CP-EBZ.