AD7865四通道同步采样快速14位模数转换器

　　The AD7865 is a fast， low power， four-channel simultaneous sampling 14-bit A/D converter that operates from a single 5 V supply. The part contains a 2.4 µs successive approximation ADC， four track/hold amplifiers， 2.5 V reference， on-chip clock oscillator， signal conditioning circuitry and a high speed parallel interface. The input signals on four channels are sampled simultaneously thus preserving the relative phase information of the signals on the four analog inputs. The part accepts analog input ranges of ±10 V， ±5 V， ±2.5 V， 0 V to 2.5 V and 0 V to 5 V. The part allows any subset of the four channels to be converted in order to maximize the throughput rate on the selected sequence. The channels to be converted can be selected either via hardware （channel select input pins） or via software （programming the channel select register）。 A single conversion start signal （CONVST） simultaneously places all the track/holds into hold and initiates conversion sequence for the selected channels. The EOC signal indicates the end of each individual conversion in the selected conversion sequence. The BUSY signal indicates the end of the conversion sequence. Data is read from the part via a 14-bit parallel data bus using the standard CS and RD signals. Maximum throughput for a single channel is 350 kSPS. For all four channels the maximum throughput is 100 kSPS.The AD7865 is available in a small （0.3 sq. inch area） 44-lead PQFP.