Datasheet AD7894 (Analog Devices)

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5 V, 14-Bit Serial, 5
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s ADC in SO-8 Package AD7894 FEATURES FUNCTIONAL BLOCK DIAGRAM Fast 14-Bit ADC with 5
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s Conversion Time 8-Lead SOIC Package REF IN VDD Single 5 V Supply Operation High Speed, Easy-to-Use, Serial Interface AD7894 On-Chip Track/Hold Amplifier Selection of Input Ranges TRACK/ SIGNAL HOLD
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10 V for AD7894-10 VIN SCALING* 14-BIT
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2.5 V for AD7894-3 ADC 0 V to +2.5 V for AD7894-2 High Input Impedance Low Power: 20 mW Typ OUTPUT CONVST REGISTER Pin Compatible Upgrade of 12-Bit AD7895 GND BUSY SCLK SDATA *AD7894-10, AD7894-3 GENERAL DESCRIPTION
The AD7894 is a fast, 14-bit ADC that operates from a single +5 V supply and is housed in a small 8-lead SOIC. The part
PRODUCT HIGHLIGHTS
contains a 5 µs successive approximation A/D converter, an on- 1. Fast, 14-Bit ADC in 8-Lead Package chip track/hold amplifier, an on-chip clock and a high speed The AD7894 contains a 5␣ µs ADC, a track/hold amplifier, serial interface. control logic and a high speed serial interface, all in an 8-lead package. This offers considerable space saving over alterna- Output data from the AD7894 is provided via a high speed, tive solutions. serial interface port. This two-wire serial interface has a serial clock input and a serial data output with the external serial clock 2. Low Power, Single Supply Operation accessing the serial data from the part. The AD7894 operates from a single +5 V supply and con- sumes only 20 mW. The automatic power-down mode, In addition to the traditional dc accuracy specifications such as where the part goes into power-down once conversion is linearity, full-scale and offset errors, the AD7894 is also speci- complete and “wakes up” before the next conversion cycle, fied for dynamic performance parameters including harmonic makes the AD7894 ideal for battery powered or portable distortion and signal-to-noise ratio. applications. The part accepts an analog input range of ± 10 V (AD7894-10), 3. High Speed Serial Interface ±2.5 V (AD7894-3), 0 V to +2.5 V (AD7894-2), and operates The part provides high speed serial data and serial clock lines from a single +5 V supply consuming only 20 mW typical. allowing for an easy, two-wire serial interface arrangement. The AD7894 features a high sampling rate mode and, for low power applications, a proprietary automatic power-down mode where the part automatically goes into power-down once conver- sion is complete and “wakes up” before the next conversion cycle. The part is available in a small outline IC (SOIC). REV. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties
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