LTC2448 Series

24-Bit High Speed 8-/16-Channel ∆∑ ADCs with Selectable Speed/Resolution

Catalog

24-Bit High Speed 8-/16-Channel ∆∑ ADCs with Selectable Speed/Resolution

Part	Number of A/D Converters	Mounting Type	Configuration	Operating Temperature [Max]	Operating Temperature [Min]	Number of Inputs	Input Type	Voltage - Supply, Digital	Reference Type	Number of Bits	Voltage - Supply, Analog	Data Interface	Architecture	Package / Case	Sampling Rate (Per Second)
Analog Devices LTC2448CUHF#PBF	1	Surface Mount	MUX-ADC	70 °C	0 °C	16 8	Differential Single Ended	5 V	External	24	5 V	SPI	Sigma-Delta	38-WFQFN Exposed Pad	8 kPer Second

Catalog

24-Bit High Speed 8-/16-Channel ∆∑ ADCs with Selectable Speed/Resolution

Key Features

• Up to 8 Differential or 16 Single-Ended Input Channels

• Up to 8kHz Output Rate

• Up to 4kHz Multiplexing Rate

• Selectable Speed/Resolution

• 2µVRMSNoise at 1.76kHz Output Rate

• 200nVRMSNoise 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 VCCCommon 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

Description

The LTC2444/LTC2445/LTC2448/LTC2449 are 8-/16- channel (4-/8-differential) high speed 24-bit No Latency ∆∑ 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/280nVRMSto 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.ApplicationsHigh Speed MultiplexingWeight ScalesAuto Ranging 6-Digit DVMsDirect Temperature MeasurementHigh Speed Data Acquisition