ADA4940-1ARZ

The ADA4940-1/ADA4940-2 are low noise, low distortion, ultralow power fully differential amplifiers ideally suited for driving low power, high resolution, high performance SAR and Σ-Δ ADCs with resolutions up to 16 bits from DC to 1 MHz, with a quiescent current of only 1.25 mA. The adjustable output common-mode level allows the ADA4940-1/ADA4940-2 to match the input common-mode voltage of multiple ADCs. An internal common-mode feedback loop provides excellent output balance and suppresses even-order harmonic distortion products. For the ADA4940-1/ADA4940-2, differential gain configuration is easily achieved using a simple external feedback network of four resistors, which determines the closed-loop gain of the amplifier. The ADA4940-1/ADA4940-2 are fabricated on a SiGe complementary bipolar process, enabling extremely low distortion levels with an input voltage noise of only 3.9 nV/√Hz. Low DC offset and excellent dynamic performance make the ADA4940-1/ADA4940-2 particularly suitable for a wide range of data acquisition and signal processing applications. The ADA4940-1 is available in lead-free, 3 mm × 3 mm, 16-lead LFCSP and 8-lead SOIC packages. The ADA4940-2 is available in a 4 mm × 4 mm, 24-lead lead-free LFCSP package. The pin configuration is optimized to facilitate PCB layout and routing while minimizing distortion. The ADA4940-1/ADA4940-2 are rated for an operating temperature range of −40°C to +125°C.

Applications

• Low-power PulSAR/SAR ADC driver
• Single-ended to differential conversion
• Differential buffer
• Line driver
• Medical imaging
• Industrial process control
• Portable electronics

Key features

• Small signal bandwidth: 260 MHz
• Ultra-low power consumption: 1.25 mA
• Extremely low harmonic distortion: −122 dB THD (50 MHz), −96 dB THD (1 MHz)
• Low input voltage noise: 3.9 nV/√Hz
• Offset voltage: 0.35 mV (maximum)
• Differential output
• 0.7% settling time: 34 ns
• Rail-to-rail output: -Vs + 0.1 V to +Vs - 0.1 V
• Adjustable output common-mode voltage
• Flexible supply: 3 V to 7 V (LFCSP)
• Disable pin for power reduction
• ADA4940-1 available in LFCSP and SOIC packages