LTC2448 - 24-Bit High Speed 8-/16-Channel Delta Sigma ADCs with Selectable Speed/Resolution

The LTC2444/LTC2445/LTC2448/LTC2449 are 8-/16- channel (4-/8-differential) high speed 24-bit No Latency Delta Sigma ADCs. They use a proprietary delta-sigma architecture enabling variable speed/resolution. Through a simple 4-wire serial interface, ten speed/resolution combinations 6.9Hz/280nVRMS to 3.5kHz/25µVRMS (4kHz with external oscillator) can be selected with no latency between conversion results or shift in DC accuracy (offset, full-scale, linearity, drift). Additionally, a 2X speed mode can be selected enabling output rates up to 7kHz (8kHz if an external oscillator is used) with one cycle latency.

Any combination of single-ended or differential inputs can be selected with a common mode input range from ground to VCC, independent of VREF. While operating in the 1X speed mode the first conversion following a new speed, resolution, or channel selection is valid. Since there is no settling time between conversions, all 8 differential channels can be scanned at a rate of 500Hz. At the conclusion of each conversion, the converter is internally reset eliminating any memory effects between successive conversions and assuring stability of the high order delta-sigma modulator.

  • Up to 8 Differential or 16 Single-Ended Input Channels
  • 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
  • LTC2445/LTC2449 Include MUXOUT/ADCIN for External Buffering or Gain
  • Tiny QFN 5mm x 7mm Package
Typical Application

  • High Speed Multiplexing
  • Weight Scales
  • Auto Ranging 6-Digit DVMs
  • Direct Temperature Measurement
  • High Speed Data Acquisition

Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC2448CUHF#PBF5x7 QFN-38C$8.75$7.15
LTC2448CUHF#TRPBF5x7 QFN-38C$7.25
LTC2448IUHF#PBF5x7 QFN-38I$10.15$8.25
LTC2448IUHF#TRPBF5x7 QFN-38I$8.35
Demo Boards
Part NumberDescriptionPrice
DC845ALTC2448UHF | 24-Bit High Speed 8-/16-Channel Delta Sigma ADC (req DC590)$50.00
Companion Boards
Part NumberDescriptionPrice
DC590BIsolated USB Serial Controller for Linear Technology QuikEval-Compatible Demo Boards$50.00
Reliability Data
Product Selector Card
Related Product
LTC2444/LTC2445/ LTC2448/LTC2449- 24-Bit High Speed 8-/16-Channel Delta Sigma ADCs with Selectable Speed/Resolution
LTC2449 Package Drawing LTC2449
LTC2449 Package Drawing LTC2449
LTC2449 Package Drawing LTC2449
R461 Reliability Data
LTC2440: 24-Bit High Speed Differential ΔΣ ADC
No Latency Delta-Sigma™ ADCs
LTC2448 Footprints and Symbols
LTC2449 - DC742A Linduino .INO File
LTC2449 Linduino .CPP File
LTC2449 Linduino Header File