Milpitas, Calif.—Linear Technology's LTC2499, suited for high-impedance sensor applications, is a 16-channel, 24-bit delta-sigma analog-to-digital converter that also includes a temperature sensor whose output can be accurately measured to within 2°C.
The ADC, which provides 2-wire I2 C-compatible serial interfacing, includes the company's Easy Drive front-end design to zero the differential input current. As a result, the ADC can be driven directly from bridges, RTDs, thermocouples and high impedance sensors (i.e, without need for a buffer); rail-to-rail input signals can be directly digitized. DC accuracy is 2 ppm INL.
The LTC2499's input multiplexer can be configured for 16 single-ended channels, eight differential channels, or combinations of both. Signals are sampled at 7.5 or 15 Hz. The chip's internal oscillator can be configured to reject line frequencies of 50, 60 or simultaneous 50/60 Hz; noise is less than 600 nV RMS across the full input voltage range. Three address-select pins allow 27 unique address combinations, in addition to a separate global address for synchronizing multiple devices.
For lower resolution applications, the company also has the new LTC2497, a 16-bit ADC. The LTC2499 and LTC2497 are each available in QFN-38 (5-by-7 mm) packages as part of a pin-compatible and code-compatible family for performance/cost optimization.
Click here for the device datasheet. Both the LTC2499 and LTC2497 are available in commercial and industrial temperature ranges. Pricing begins at $3.45 each for the LTC2499 and $2.65 each for the LTC2497 in 1k-piece quantities.
Linear Technology , 1-800-4LINEAR, www.linear.com