ANALOG DEVICES AD7641 18-Bit, 2 MSPS SAR ADC User's Manual

18-Bit, 2 MSPS SAR ADC

AD7641 FEATURES FUNCTIONAL BLOCK DIAGRAM

Throughput TEMP REFBUFIN REF REFGND DGNDDVDD

2 MSPS (wideband warp and warp mode)

1.5 MSPS (normal mode) AD7641 OVDD

INL: ±2 LSB typical, ±3 LSB max; ±8 ppm of full scale OGND

REF 18-bit resolution with no missing codes REF AMP

SERIAL PORT

Dynamic range: 95.5 d B IN+

SWITCHED

SNR: 93.5 d B typical @ 20 k Hz (VREF = 2.5 V) IN– CAP DAC

MODE0

PARALLEL

THD: −112 d B typical @ 20 k Hz (VREF = 2.5 V) INTERFACE

MODE1

2.048 V internal reference: typ drift 10 ppm/°C; TEMP output

PDREF CLOCK BUSY

Differential input range: ±VREF (VREF up to 2.5 V) PDBUF RD

CONTROL LOGIC AND

No pipeline delay (SAR architecture) PD CS

CALIBRATION CIRCUITRY

Parallel (18-, 16-, or 8-bit bus) and RESET D0/OB/2C

serial 5 V/3.3 V/2.5 V interface

SPI®/QSPI™/MICROWIRE™/DSP compatible WARP NORMAL CNVST

Single 2.5 V supply operation Figure 1.

Power dissipation

Table 1. Pul SAR® Selection

75 m W typical @ 2 MSPS with internal REF

100 to 500 to 650 to

2 μW in power-down mode Type/k SPS 1000 >1000 Pb-free, 48-lead LQFP and 48-lead LFCSP_VQ Pseudo AD7651, AD7650, AD7653,

Speed upgrade of the AD7674, AD7678, AD7679 Differential AD7660, AD7652, AD7667 AD7661 AD7664,

AD7666

APPLICATIONS

True Bipolar AD7610, AD7665 AD7612,

Medical instruments AD7663 AD7671 High speed data acquisition/high dynamic data acquisition True AD7675 AD7676 AD7677 AD7621,

Digital signal processing Differential AD7622,

AD7623

Spectrum analysis

18-Bit AD7631, AD7679 AD7634, AD7641,

Instrumentation

Multichannel/ AD7678 AD7674 AD7643

Communications

Simultaneous AD7654 AD7655

PRODUCT HIGHLIGHTS

GENERAL DESCRIPTION

1. Fast Throughput.

The AD7641 is an 18-bit, 2 MSPS, charge redistribution SAR,

The AD7641 is a 2 MSPS, charge redistribution,

fully differential, analog-to-digital converter (ADC) that

18-bit SAR ADC.

operates from a single 2.5 V power supply. The part contains a 1-

2. Superior Linearity.

high speed, 18-bit sampling ADC, an internal conversion clock,

The AD7641 has no missing 18-bit code.

an internal reference (and buffer), error correction circuits, and

both serial and parallel system interface ports. It features two 3. Internal Reference. very high sampling rate modes (wideband warp and warp) and The AD7641 has a 2.048 V internal reference with a typical

a fast mode (normal) for asynchronous rate applications. The -chip TEMP sensor. drift of ±10 ppm/°C and an on

AD7641 is hardware factory calibrated and tested to ensure ac Single-Supply Operation. 4. parameters, such as signal-to-noise ratio (SNR), in addition to The AD7641 operates from a 2.5 V single supply. the more traditional dc parameters of gain, offset, and linearity. 5.

Serial or Parallel Interface.

The AD7641 is available in Pb-free only packages with

Versatile parallel (16- or 8-bit bus) or 2-wire serial interf ace

operation specified from −40°C to +85°C.

arrangement compatible with 2.5 V, 3.3 V, or 5 V logic.

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