AD7944BCPZ

The AD7944 is a 14-bit, 2.5 MSPS successive approximation analog-to-digital converter (SAR ADC). It contains a low power, high speed, 14-bit sampling ADC, an internal conversion clock, an internal reference (and buffer), error correction circuits, and a versatile serial interface port. On the rising edge of CNV, the AD7944 samples an analog input, IN+ between 0V and VREF with respect to a ground sense, IN-. The AD7944 features a very high sampling rate turbo mode (TURBO high) and a reduced power normal mode (TURBO low) for low power applications where the power is scaled with the throughput. In normal mode (TURBO low), the SPI-compatible serial interface also features the ability, using the SDI input, to daisy-chain several ADCs on a single 3-wire bus and provide an optional busy indicator. The serial interface is compatible with 1.8 V, 2.5 V, and 2.7 V supplies using the separate VIO supply. The AD7944 is available in a 20-lead LFCSP with operation specified from -40°C to +85°C

Applications

• Battery-powered equipment
• Communications
• ATE
• Data acquisition systems
• Medical instruments

Key features

• 14-bit resolution with no missing codes
• Throughput: 2.5 MSPS (TURBO high), 2.0 MSPS (TURBO low)
• Low power dissipation
• 15.5 mW at 2.5 MSPS, with external reference
• 28 mW at 2.5 MSPS, with internal reference
• INL: ±0.25 LSB typical, ±1.0 LSB maximum
• SNR 84 dB, with on-chip reference
• 84.5 dB, with external reference
• 4.096 V internal reference: typical drift of ±10 ppm/°C
• Pseudo differential analog input voltage range 0 V to VREF with VREF upto 5.0 V
• Allows use of any input range
• No pipeline delay
• Logic interface: 1.8 V/2.5 V/2.7 V
• Proprietary serial interface
• SPI/QSPI/MICROWIRE/DSK compatible
• Ability to daisy-chain multiple ADCs with busy indicator
• 20-lead, 4 mm × 4 mm LFCSP (QFN)