描述The ADS7881 is a 12-bit 4-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 12-bit parallel interface with an additional byte mode that provides easy interface with 8-bit processors. 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. With nap mode enabled, the device operates at lower power when used at lower conversion rates. The device is available in a 48-pin TQFP package.特性4 MHz Sample Rate, 12-Bit Resolution Zero Latency Unipolar, Pseudo Differential Input, Range: 0 V to 2.5 V High Speed Parallel Interface 71 dB SNR and –88.5 dB THD at 1 MHz I/P Power Dissipation 95 mW at 4 MSPS Nap Mode (10 mW Power Dissipation) Power Down (10 µW) 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 Ultra-Sound Detection