AD7887

The AD7887 is a high speed, low power, 12-bit ADC that oper-ates from a single +2.7 V to +5.25 V power supply. The AD7887 is capable of 125 kSPS throughput rate. The input track-and- hold acquires a signal in 500 ns and features a single-ended sampling scheme. The output coding for the AD7887 is straight binary and the part is capable of converting full power signals up to 2.5 MHz.

The AD7887 can be configured for either dual or single chan-nel operation, via the on-chip Control Register. There is a default single-channel mode that allows the AD7887 to be operated as a read-only ADC. In single-channel operation, there is one analog input (AIN0) with the V _REF/AIN1 pin as-suming its V_REFfunction. This V_REFpin allows the user access to the part's internal +2.5 V reference, or the V_REFpin can be overdriven by an external reference to provide the reference voltage for the part. This external reference voltage has a range of +2.5 V to V_DD. The analog input range on AIN0 is 0 to +V_REF.

In dual-channel operation, the V_REF/AIN1 pin assumes its AIN1 function, providing a second analog input channel. In this case, the reference voltage for the part is provided via the V_DD pin. As a result, the input voltage range on both the AIN0 and AIN1 inputs is 0 to V_DD.