ADA4938-2

The ADA4938-x is fabricated using the Analog Devices, Inc., proprietary third generation, high voltage XFCB process, enabling it to achieve very low levels of distortion with an input voltage noise of only 2.6 nV/Hz. The low dc offset and excellent dynamic performance of the ADA4938-x make it well-suited for a wide variety of data acquisition and signal processing applications. The ADA4938-1 (single amplifier)is available in a Pb-free, 3 mm * 3 mm, 16-lead LFCSP. The ADA4938-2 (dual amplifier)is available in a Pb-free, 4 mm * 4 mm, 24-lead LFCSP. The pinouts have been optimized to facilitate layout and minimize distortion. The parts are specified to operate over the extended industrial temperature range of -40°C to +85°C. The ADA4938-x is a low noise, ultralow distortion, high speed differential amplifier. It is an ideal choice for driving high performance ADCs with resolutions up to 16 bits from dc to 27 MHz, or up to 12 bits from dc to 74 MHz. The output common-mode voltage is adjustable over a wide range, allowing the ADA4938 to match the input of the ADC. The internal common-mode feedback loop also provides exceptional output balance as well as suppression of even-order harmonic distortion products. Full differential and single-ended-to-differential gain configurations are easily realized with the ADA4938-x. A simple external feedback network of four resistors determines the closed-loop gain of the amplifier.

The features of ADA4938-2 can be summarized as (1)extremely low harmonic distortion (HD)-106 dBc HD2 @ 10 MHz/ -82 dBc HD2 @ 50 MHz/ -109 dBc HD3 @ 10 MHz/ -82 dBc HD3 @ 50 MHz; (2)low input voltage noise: 2.6 nV/Hz; (3)high speed -3 dB bandwidth of 1000 MHz, G = +1/ slew rate: 4700 V/s/ 0.1 dB gain flatness to 150 MHz/ fast overdrive recovery of 4 ns; (4)1 mV typical offset voltage; (5)externally adjustable gain; (6)differential-to-differential or single-ended-to-differential operation; (7)adjustable output common-mode voltage; (8)wide supply voltage range: +5 V to ±5 V; (9)single or dual amplifier configuration available.

The absolute maximum ratings of ADA4938-2 are (1)supply voltage: 12 V; (2)power dissipation: See Figure 4; (3)storage temperature range: -65°C to +125°C; (4)operating temperature range: -40°C to +85°C; (5)lead temperature (Soldering, 10 sec): 300°C; (6)junction temperature: 150°C .