Features and Benefits
- Five Selectable Differential Reference Inputs
- Four Differential/Eight Single-Ended Inputs
- 4-Way MUX for Multiple Ratiometric Measurements
- Up to 8kHz Output Rate
- Up to 4kHz Multiplexing Rate
- Selectable Speed/Resolution:
- 2µVRMS Noise at 1.76kHz Output Rate
- 200nVRMS Noise at 13.8Hz Output Rate with
- Simultaneous 50/60Hz Rejection
- Guaranteed Modulator Stability and Lock-Up Immunity for any Input and Reference Conditions
- 0.0005% INL, No Missing Codes
- Autosleep Enables 20µA Operation at 6.9Hz
- <5µV Offset (4.5V < VCC < 5.5V, –40°C to 85°C)
- Differential Input and Differential Reference with GND to VCC Common Mode Range
- No Latency Mode, Each Conversion is Accurate Even After a New Channel is Selected
- Internal Oscillator—No External Components
- LTC2447 Includes MUXOUT/ADCIN for External Buffering or Gain
- Tiny QFN 5mm x 7mm Package
The LTC2446/LTC2447 4-terminal switching enables multiplexed ratiometric measurements. Four sets of selectable differential inputs coupled with four sets of differential reference inputs allow multiple RTDs, bridges and other sensors to be digitized by a single converter. A fifth differential reference input can be selected for any input channel not requiring ratiometric measurements (thermocouples, voltages, current sense, etc.). The flexible input multiplexer allows single-ended or differential inputs coupled with a slaved reference input or a universal reference input.
A proprietary delta-sigma architecture results in absolute accuracy (offset, full-scale, linearity) of 15ppm, noise as low as 200nVRMS and speeds as high as 8kHz. Through a simple 4-wire interface, ten speed/resolution combinations can be selected. The first conversion following a speed, resolution, channel change or reference change is valid since there is no settling time between conversions, enabling scan rates of up to 4kHz. Additionally, a 2x mode can be selected for any speed-enabling output rates up to 8kHz with one cycle of latency.
Protected by U.S. Patents, including 6140950, 6169506, 6208279, 6411242, 6639526
- Weight Scales
- Direct Temperature Measurement
- Gas Chromatography
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.