
Analog Devices
GENERAL DESCRIPTION
The AD7899 is a fast, low-power, 14-bit A/D converter that operates from a single 5 V supply. The part contains a 2.2 µs successive-approximation ADC, a track/hold amplifier, 2.5 V reference, on-chip clock oscillator, signal conditioning circuitry, and a high-speed parallel interface. 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. Overvoltage protection on the analog input for the part allows the input voltage to be exceeded without damaging the parts.
Speed of conversion can be controlled either by an internally trimmed clock oscillator or by an external clock.
PRODUCT HIGHLIGHTS
1. The AD7899 features a fast (2.2 µs) ADC allowing through put rates of up to 400 kSPS.
2. The AD7899 operates from a single 5 V supply and consumes only 80 mW typ making it ideal for low power and portable applications.
3. The part offers a high-speed parallel interface. The interface can operate in 3 V and 5 V mode allowing for easy connec tion to 3 V or 5 V microprocessors, microcontrollers, and digital signal processors.
4. The part is offered in three versions with different analog input ranges. The AD7899-1 offers the standard industrial ranges of ±10 V and ±5 V; the AD7899-2 offers a unipolar range of 0 V to 2.5 or 0 V to 5 V, and the AD7899-3 has an input range of ±2.5 V.
FEATURES
Fast (2.2 μs) 14-Bit ADC
400 kSPS Throughput Rate
0.3 μs Track/Hold Acquisition Time
Single Supply Operation
Selection of Input Ranges: ±10 V, ±5 V and ±2.5 V 0 V to 2.5 V and 0 V to 5 V
High-Speed Parallel Interface which Also Allows Interfacing to 3 V Processors
Low Power, 80 mW Typ
Power-Saving Mode, 20 μW Typ
Overvoltage Protection on Analog Inputs
Power-Down Mode via STBY Pin