Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs

The MAX1108/MAX1109 low-power, 8-bit, dual-channel, analog-to-digital converters (ADCs) feature an internal track/hold (T/H) voltage reference, clock, and serial interface. The MAX1108 is specified from +2.7V to +3.6V and consumes only 105µA. The MAX1109 is specified from +4.5V to +5.5V and consumes only 130µA. The analog inputs are software configurable, allowing unipolar/bipolar and single-ended/differential operation; battery monitoring capability is also included.

The full-scale analog input range is determined by the internal reference of +2.048V (MAX1108) or +4.096V (MAX1109), or by an externally applied reference ranging from 1V to VDD. The MAX1108/MAX1109 also feature a software power-down mode that reduces power consumption to 0.5µA when the device is not in use. The 4-wire serial interface directly connects to SPI™, QSPI™, and MICROWIRE™ devices without external logic. Conversions up to 50ksps are performed using either the internal clock or an external serial-interface clock.

The MAX1108 and MAX1109 are available in a 10-pin µMAX package with a footprint that is just 20% of an 8-pin plastic DIP.

Applications

* 4mA- to 20mA-Powered Remote Systems * Handheld Measurement Devices * Medical Instruments * Portable Data Logging * Receive Signal Strength Indicators * Solar-Powered Remote Systems * System Diagnostics

* Single Supply:

* +2.7V to +3.6V (MAX1108)

* +4.5V to +5.5V (MAX1109)

* Low Power:

* 105µA at +3V and 50ksps

* 0.5µA in Power-Down Mode

* Software-Configurable Unipolar or Bipolar Inputs

* Input Voltage Range: 0 to VDD

* Internal Track/Hold

* Internal Reference:

* +2.048V (MAX1108)

* +4.096V (MAX1109)

* Reference Input Range: 1V to VDD

* SPI/QSPI/MICROWIRE-Compatible Serial Interface

* VDD Monitoring Mode

* Small 10-Pin µMAX Package