Datasheet AD7823 (Analog Devices)

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2.7 V to 5.5 V, 5
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s, 8-Bit ADC in 8-Lead microSOIC/DIP AD7823 FEATURES FUNCTIONAL BLOCK DIAGRAM 8-Bit ADC with 4
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s Conversion Time V Small Footprint 8-Lead microSOIC Package DD AGND VREF Specified Over a –40
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C to +125
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C Temperature Range Inherent Track-and-Hold Functionality AD7823 CHARGE DOUT SERIAL REDISTRIBUTION Operating Supply Range: 2.7 V to 5.5 V PORT DAC SCLK Specifications at 2.7 V to 5.5 V and 5 V
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10% CLOCK Microcontroller Compatible Serial Interface OSC Optional Automatic Power-Down VIN+ Low Power Operation: CONTROL 570
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W at 10 kSPS Throughput Rate V COMP IN– LOGIC VDD/3 2.9 mW at 50 kSPS Throughput Rate Analog Input Range: 0 V to VREF Reference Input Range: 0 V to VDD CONVST “Drop In” Upgrade to 10 Bits Available (AD7810) APPLICATIONS Low Power, Hand-Held Portable Applications Requiring Analog-to-Digital Conversion with 8-Bit Accuracy, e.g., Battery-Powered Test Equipment Battery-Powered Communications Systems GENERAL DESCRIPTION PRODUCT HIGHLIGHTS
The AD7823 is a high speed, low power, 8-bit A/D converter 1. Complete, 8-Bit ADC in 8-Lead Package that operates from a single 2.7 V to 5.5 V supply. The part con- The AD7823 is an 8-bit 4 µs typ ADC with inherent track- tains a 4 µs typ successive approximation A/D converter, inherent and-hold functionality and a high speed serial interface—all track-and-hold functionality (with a pseudo differential input) in an 8-lead microSOIC package. VREF may be connected to and a high speed serial interface that interfaces to most microcon- VDD to eliminate the need for an external reference. The result trollers. The AD7823 is fully specified over a temperature range is a high speed, low power, space saving ADC solution. of –40°C to +125°C. 2. Low Power, Single Supply Operation By using a technique that samples the state of the CONVST The AD7823 operates from a single 2.7 V to 5.5 V supply and (convert start) signal at the end of a conversion, the AD7823 typically consumes only 9 mW of power. The power dissipa- may be used in an automatic power-down mode. When used in tion can be significantly reduced at lower throughput rates by this mode, the AD7823 powers down automatically at the end using the automatic power-down mode, e.g., at a throughput of a conversion and “wakes up” at the start of a new conversion. rate of 10 kSPS the power consumption is only 570 µW. This feature significantly reduces the power consumption of the 3. Automatic Power-Down part at lower throughput rates. The AD7823 can also operate in The automatic power-down mode, whereby the AD7823 a high speed mode where the part is not powered down between “powers down” at the end of a conversion and “wakes up” conversions. In this high speed mode of operation, the conver- before the next conversion, means the AD7823 is ideal for sion time of the AD7823 is 4 µs typ. The maximum throughput battery powered applications. See Power vs. Throughput rate is dependent on the speed of the serial interface of the Rate section. microcontroller. 4. Serial Interface The part is available in a small, 8-lead 0.3" wide, plastic dual-in- An easy to use, fast serial interface allows connection to most line package (mini-DIP); in an 8-lead, small outline IC (SOIC); popular microprocessors with no external circuitry. and in an 8-lead microSOIC package. REV. C 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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