GENERAL DESCRIPTION

The AD7643 is an 18-bit, 1.25 MSPS, charge redistribution SAR, fully differential, analog-to-digital converter (ADC) that operates from a single 2.5 V power supply. The part contains a high speed, 18-bit sampling ADC, an internal conversion clock, an internal reference (and buffer), error correction circuits, and both serial and parallel system interface ports. The part has no latency and can be used in asynchronous rate applications. The AD7643 is hardware factory calibrated and tested to ensure ac parameters, such as signal-to-noise ratio (SNR), in addition to the more traditional dc parameters of gain, offset, and linearity. The AD7643 is only available in Pb-free packages with operation specified from −40°C to +85°C.

FEATURES

Throughput: 1.25 MSPS

INL: ±1.5 LSB typical, ±3 LSB maximum (±11 ppm of full scale)

18-bit resolution with no missing codes

Dynamic range: 95dB typical

SINAD: 93.5dB typical @ 20 kHz (VREF= 2.5 V)

THD: −113dB typical @ 20 kHz (VREF= 2.5 V)

2.048 V internal reference: typical drift 8ppm/°C; TEMP output

Differential input range: ±VREF(VREFup to 2.5 V)

No pipeline delay (SAR architecture)

Parallel (18-, 16-, or 8-bit bus) and serial 5 V/3.3 V/2.5 V interface

SPI®/QSPI™/MICROWIRE™/DSP compatible

Single 2.5 V supply operation

Power dissipation

65mW typical @ 1.25MSPS with internal REF

2 μW in power-down mode

Pb-free, 48-lead LQFP and 48-lead LFCSP_VQ

Pin compatible with the AD7641and other PulSAR ADC’s

APPLICATIONS

Medical instruments

High speed data acquisition/high dynamic data acquisition

Digital signal processing

Spectrum analysis

Instrumentation

Communications

ATE

AD7643属于集成电路（IC） > 模数转换器（ADC）。亚德诺半导体技术有限公司制造生产的AD7643模数转换器（ADC）模数转换器（ADC、A/D 或 A 转 D）对模拟信号进行采样，例如由麦克风采集的声音或传感器的输出，然后将其转换为数字信号。一般来说，数字输出是二进制补码二进制数，与输入成比例。输入类型可能是差分、伪差分或单端输入。模数转换器可按照位数、采样率、输入数、接口、转换器数和架构（例如自适应增量、双斜率、折叠、流水线、SAR、三角积分、两步式）进行选择。