AD7688 Datasheet

• 16 Bits Resolution with No Missing 16-Bit Codes
• Throughput: 500 kSPS
• INL: ±0.4 LSB Typ, ±1.5 LSB Max
• S/(N+D): 95 dB @ 20 kHz
• Power Dissipation:
  4 mW @ 100 kSPS
  4 µW @ 100 SPS
• True Differential Analog input range: ±V_REF 0 V to V_REF with V_REF up to VDD on Both Inputs
• No Pipeline Delay
• Single Supply 5V Operation with 1.8V to 5 V Logic Interface
• Multiple ADCs Daisy Chain, with BUSY Indicator
• Serial Interface SPI/QSPI/Wire/DSP compatible
• µSOIC Package (µSO8 Size) and 3 mm by 3 mm QFN (LFCSP) (SOT23 size)
• Pin-to-Pin Compatible with the AD7685, AD7686, AD7687

• Battery Powered Equipment
• Medical instruments
• Mobile communications
• Personal digital assistants
• Data Acquisition
• Instrumentation
• Medical Instruments
• Process Control

The AD7688 is a 16-bit, 500 kSPS, charge redistribution successive-approximation Analog-to-Digital Converter which operates from a single 5V power supply, VDD. It contains a very low power high-speed 16-bit sampling ADC with no missing codes, an internal conversion clock and a versatile serial interface port. The part also contains a low noise, wide bandwidth, very short aperture delay track/hold circuit. On the CNV rising edge, it samples the voltage difference between IN+ and IN- pins. The voltages on these pins usually swing in opposite phase between 0 V to REF. The reference voltage REF is applied externally and can be set up to the supply voltage.

Its power scales linearly with throughput.

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 provides an optional Busy indicator. It is compatible with 1.8 V, 2.5 V, 3 V or 5 V logic using the separate supply VIO.

The AD7688 is housed in a 10-lead µSOIC or 10-lead QFN (Chip Scale package) with operation