FEATURES

1.25 MHz Sample Rate, 14-Bit Resolution

Zero Latency

Unipolar, Pseudo Differential Input, Range:

− 0 V to 2.5 V

SPI
Compatible Serial Interface

77.5 dB SNR and −95 dB THD at 0.5 MHz I/P

Power Dissipation 45 mW at 1.25 MSPS

Nap Mode (10 mW Power Dissipation)

Power Down (10
W)

Internal Reference

Internal Reference Buffer

48-Pin TQFP Package

APPLICATIONS

Optical Networking (DWDM, MEMS Based

Switching)

Spectrum Analyzers

High Speed Data Acquisition Systems

High Speed Close-Loop Systems

Telecommunication

DESCRIPTION

The ADS7890 is a 14-bit 1.25-MSPS A-to-D converter with 2.5-V internal reference. The device includes a

capacitor based SAR A/D converter with inherent sample and hold. The device offers a 14-bit serial SPI or DSP

compatible interface. The device has a pseudo-differential input stage.

The −IN swing of ±200 mV is useful to compensate for ground voltage mismatch between the ADC and sensor

and also to cancel common-mode noise. The device operates at lower power when used at lower conversion

rates because of the nap feature. The device is available in a 48-pin TQFP package.