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.