SBAS280E − JUNE 2003 − REVISED MAY 2007

18Bit, 1.25MSPS

AnalogtoDigital Converter

ADS1625

ADS1626

FEATURES

+5V

Digital

+3V

Digital I/O +2.7V to +5.25V

APPLICATIONS

DESCRIPTION

The ADS1625 and ADS1626 are high-speed, high-precision,

delta-sigma analog-to-digital converters (ADCs) with 18-bit

resolution. The data rate is 1.25 mega samples per second

(MSPS), the bandwidth (−3dB) is 615kHz, and passband

ripple is less than

the same outstanding performance at these speeds with a

signal-to-noise ratio up to 93dB, total harmonic distortion

down to −101dB, and a spurious-free dynamic range up to

103dB. The ADS1626 includes an adjustable first-in, first-out

buffer (FIFO) for the output data.

The input signal is measured against a voltage reference that

can be generated on-chip or supplied externally. The digital

output data are provided over a simple parallel interface that

easily connects to digital signal processors (DSPs). An

out-of-range monitor reports when the input range has been

exceeded. The ADS1625/6 operate from a +5V analog

supply (AVDD) and +3V digital supply (DVDD). The digital

I/O supply (IOVDD) operates from +2.7 to +5.25V, enabling

the digital interface to support a range of logic families. The

analog power dissipation is set by an external resistor and

can be reduced when operating at slower speeds. A

power-down mode, activated by a digital I/O pin, shuts down

all circuitry. The ADS1625/6 are offered in a TQFP-64

package using TI PowerPAD

 technology.

The ADS1625 and ADS1626, along with their 16-bit,

5MSPS counterparts, the ADS1605 and ADS1606, are

well-suited for the demanding measurement requirements

of scientific instrumentation, automated test equipment,

data acquisition, and medical imaging.

REFEN

Reference and Bias Circuits

I/O

Interface

Digital

Filter

∆Σ

Modulator

VREFP VREFN

RBIAS

VMID

VCAP

AVDD DVDD IOVDD

DGND

AGND

AINP

AINN

PD

CLK

CS

RESET

RD

DRDY

DOUT[17:0]

FIFO_LEV[2:0]

OTR

ADS1626 Only

FIFO

ADS1625

ADS1626

PowerPAD is a trademark of Texas Instruments. All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date. Products

conform to specifications per the terms of Texas Instruments standard warranty.

Production processing does not necessarily include testing of all parameters.

www.ti.com

Copyright

 2003−2007, Texas Instruments Incorporated

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments

semiconductor products and disclaimers thereto appears at the end of this data sheet.