16-Bit, 4-Channel/8-Channel,

250 kSPS PulSAR ADC Data Sheet AD7682/AD7689

Rev. D

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16-bit resolution with no missing codes

4-channel (AD7682)/8-channel (AD7689) multiplexer with choice of inputs

Unipolar single-ended

Differential (GND sense)


Throughput: 250 kSPS

INL: ±0.4 LSB typical, ±1.5 LSB maximum (±23 ppm or FSR) Dynamic range: 93.8 dB

SINAD: 92.5 dB at 20 kHz

THD: −100 dB at 20 kHz

Analog input range: 0 V to V REF with V REF up to VDD Multiple reference types

Internal selectable 2.5 V or 4.096 V

External buffered (up to 4.096 V)

External (up to VDD)

Internal temperature sensor (TEMP)

Channel sequencer, selectable 1-pole filter, busy indicator No pipeline delay, SAR architecture

Single-supply 2.3 V to 5.5 V operation with

1.8 V to 5.5 V logic interface

Serial interface compatible with SPI, MICROWIRE, QSPI, and DSP

Power dissipation

3.5 mW @ 2.5 V/200 kSPS

12.5 mW @ 5 V/250 kSPS

Standby current: 50 nA

Low cost grade available

20-lead 4 mm × 4 mm LFCSP package APPLICATIONS

Multichannel system monitoring

Battery-powered equipment

Medical instruments: ECG/EKG

Mobile communications: GPS

Power line monitoring

Data acquisition

Seismic data acquisition systems


Process control









Figure 1.

Table 1. Multichannel 14-/16-Bit PulSAR® ADC

Type Channels 250 kSPS 500kSPS ADC

Driver 14-Bit 8 AD7949 ADA4841-x 16-Bit 4 AD7682ADA4841-x


The AD7682/AD7689 are 4-channel/8-channel, 16-bit, charge redistribution successive approximation register (SAR) analog-to-digital converters (ADCs) that operate from a single power supply, VDD.

The AD7682/AD7689 contain all components for use in a multichannel, low power data acquisition system, including a true 16-bit SAR ADC with no missing codes; a 4-channel

(AD7682) or 8-channel (AD7689), low crosstalk multiplexer that is useful for configuring the inputs as single-ended (with or without ground sense), differential, or bipolar; an internal low drift reference (selectable 2.5 V or 4.096 V) and buffer; a temperature sensor; a selectable one-pole filter; and a sequencer that is useful when channels are continuously scanned in order. The AD7682/AD7689 use a simple SPI interface for writing to the configuration register and receiving conversion results. The SPI interface uses a separate supply, VIO, which is set to the host logic level. Power dissipation scales with throughput.

The AD7682/AD7689 are housed in a tiny 20-lead LFCSP with operation specified from −40°C to +85°C.