austriamicrosystems AG is now ams AG The technical content of this austriamicrosystems datasheet is still valid. Contact information: Headquarters: ams AG Tobelbaderstrasse 30 8141 Unterpremstaetten, Austria Tel: +43 (0) 3136 500 0 e-Mail: ams sales ams.com Please visit our website at www.ams.com Dat a Sh eet AS1538/AS1540 8/4-Channel, 12-Bit IC Analog-to-Digital Converter 1 General Description 2 Key Features Single Supply: 2.7 to 5.25V The AS1538/AS1540 are single-supply, low-power, 12- bit data acquisition devices featuring a serial IC inter- face and an 8-channel (AS1538) or 4-channel (AS1540) 8-Channel Multiplexer (AS1538) multiplexer. 4-Channel Multiplexer (AS1540) The analog-to-digital (A/D) converters features a sam- ple-and-hold amplifier an internal asynchronous clock and an internal reference. Sampling Rate: 50kSPS 2 The combination of an I C serial, 2-wire interface and No Missing Codes micropower consumption makes the AS1538 and AS1540 ideal for applications requiring the A/D con- Internal Reference: 2.5V verter to be close to the input source in remote locations and for applications requiring isolation. 2 High Speed I C Interface at 3.4MHz The device is available in a TSSOP-16 or TQFN 4x4 16- pin package. <1.5A Full Shutdown Current TSSOP-16 or TQFN 4x4 16-pin Package 3 Applications The device is ideal for voltage-supply monitoring, iso- lated data acquisition, transducer interfaces, battery- operated systems, remote data acquisition or any other analog-to-digital conversion application. Figure 1. Block Diagram CH0 SDA Successive Approximation Register CH1 Serial SCL Interface CH2 AS1538/AS1540 A0 CH3 8-Channel MUX A1 CH4 Sample/ Comparator CDAC Hold Amp CH5 CH6 CH7 COM Internal Buffer 2.5V REFIN/OUT GND Reference www.austriamicrosystems.com Revision 1.03 1 - 20 ams AG Technical content still valid AS1538 only