12-Bit, 10mW, 100ksps ADCs with 1µA Shutdown

The LTC1274/LTC1277 are 8µs sampling 12-bit A/D converters which draw only 2mA (typ) from single 5V or ±5V supplies. These easy-to-use devices come complete with a 2µs sample-and-hold, a precision reference and an internally trimmed clock. Unipolar and bipolar conversion modes add to the flexibility of the ADCs.

Two power-down modes are available in the LTC1277. In Napmode, the LTC1277 draws only 180µA and the instant wake-up from Nap mode allows the LTC1277 to be powered down even during brief inactive periods. In Sleep mode only 1µA will be drawn. A REFRDY signal is used to show the ADC is ready to sample after waking up from Sleep mode. The LTC1274 also provides the Sleep mode and REFRDY signal.

The A/D converters convert 0V to 4.096V unipolar inputs from a single 5V supply or ±2.048V bipolar inputs from ±5V supplies.

The LTC1274 has a single-ended input and a 12-bit parallel data format. The LTC1277 offers a differential input and a 2-byte read format. The bipolar mode is formatted as 2’s complement for the LTC1274 and offset binary for the LTC1277.

Applications

* Battery-Powered Portable Systems

* High Speed Data Acquisition for PCs

* Digital Signal Processing

* Multiplexed Data Acquisition Systems

* Audio and Telecom Processing

* Spectrum Analysis

* Low Power Dissipation: 10mW

* Sample Rate: 100ksps

* Samples Inputs Beyond Nyquist, 72dB S/(N + D) and 82dB THD at fIN = 100kHz

* Single Supply 5V or ±5V Operation

* Power Shutdown to 1µA in Sleep Mode

* 180µA Nap Mode (LTC1277) with Instant Wake-Up

* Internal Reference Can Be Overdriven

* Internal Synchronized Clock

* 0V to 4.096V or ±2.048V Input Ranges (1mV/LSB)

* 24-Lead SOL Package