Datasheet LTC2442 (Analog Devices)

LTC2442 24-Bit High Speed 4-Channel DS ADC with Integrated Amplifier
FEATURES DESCRIPTION
n
1ppm Linearity with No Missing Codes
The LTC®2442 is an ultra high precision, variable speed, n
Integrated Amplifier for Direct Sensor Digitization
24-bit DS™ ADC with integrated amplifier. The amplifier n
2 Differential or 4 Single-Ended Input Channels
can be configured as a buffer for easy input drive of high n
Up to 8kHz Output Rate (External fO)
impedance sensors. 1 part-per-million (ppm) linearity is n
Up to 4kHz Multiplexing Rate (External fO)
achievable when the amplifier is configured in unity gain. n
Selectable Speed/Resolution
External resistors can be used to set a gain for increased
2.1µVRMS Noise at 1.76kHz Output Rate
resolution of low level input signals. The positive and
220nVRMS Noise at 13.8Hz Output Rate with
negative amplifier supply pins may be tied directly to VCC
Simultaneous 50Hz/60Hz Rejection
(4.5V to 5.5V) and GND or biased above VCC and below n Guaranteed Modulator Stability and Lock-Up GND for rail-to-rail input signals. Immunity for any Input and Reference Conditions The proprietary DS architecture ensures stable DC ac- n <5µV Offset (4.5V < VCC < 5.5V, –40°C to 85°C) curacy through continuous transparent calibration. Ten n Differential Input and Differential Reference with GND speed/resolution combinations from 6.9Hz/220nVRMS to to VCC Common Mode Range 3.5kHz/25µVRMS can be selected with no latency or shift n No Latency Mode, Each Conversion is Accurate Even in DC accuracy. Additionally, a 2X speed mode can be After a New Channel is Selected selected enabling output rates up to 7kHz (8kHz with an n Internal Oscillator—No External Components external oscillator) with one cycle latency. n 36-Lead SSOP Package Any combination of single-ended (up to 4 inputs) or dif-
APPLICATIONS
ferential (up to 2 inputs) can be selected with a common mode input range from ground to VCC. While operating in n Auto Ranging 6-Digit DVMs the 1X speed mode the first conversion following a new n High Speed Multiplexing speed/resolution or channel selection is valid. n Weight Scales L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear n Direct Temperature Measurement Technology Corporation. No Latency DS and SoftSpan are trademarks of Linear Technology n High Speed Data Acquisition Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 6140950, 6169506, 6411242, 6639526.
TYPICAL APPLICATION High Precision Data Acquisition System LTC2442 Integral Non-Linearity
5 0.1µF V 4 INCM = 2.048V VREF = 4.096V 4.5V TO 15V 4.5V TO 5.5V 3 VCC = 5V V+ = 5V = EXTERNAL OSCILLATOR 2 V– = 0V V+ VREF+ VCC FO = INTERNAL OSCILLATOR (SIMULTANEOUS 50Hz/60Hz 1 CH0 REJECTION AT 6.9Hz OUTPUT RATE) – SDI 0 CH1 HIGH Z + SCK VARIABLE SPEED/ 4-WIRE 2-CHANNEL –1 RESOLUTION SDO SPI INTERFACE DIFFERENTIAL/ CH2 AUTO-CAL DIFFERENTIAL + CS INL ERROR (ppm) 4-CHANNEL –2 24-BIT ∆Σ ADC SINGLE ENDED CH3 – –3 COM –4 V– VREF– GND LTC2442 2442 TA01 –5 –2.048 –1.024 0 1.024 2.048 –15V TO 0V 0.1µF VIN DIFFERENTIAL (V) 2442 TA02 2442fb For more information www.linear.com/LTC2442 1