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 f ) impedance sensors. 1 part-per-million (ppm) linearity is O n Up to 4kHz Multiplexing Rate (External f ) achievable when the amplifier is configured in unity gain. O n Selectable Speed/Resolution External resistors can be used to set a gain for increased 2.1V Noise at 1.76kHz Output Rate resolution of low level input signals. The positive and RMS 220nV Noise at 13.8Hz Output Rate with negative amplifier supply pins may be tied directly to V RMS CC Simultaneous 50Hz/60Hz Rejection (4.5V to 5.5V) and GND or biased above V and below CC 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 <5V Offset (4.5V < V < 5.5V, 40C to 85C) CC curacy through continuous transparent calibration. Ten n Differential Input and Differential Reference with GND speed/resolution combinations from 6.9Hz/220nV to RMS to V Common Mode Range CC 3.5kHz/25V can be selected with no latency or shift RMS 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 OscillatorNo 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 V . While operating in CC 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 and SoftSpan are trademarks of Linear TDS echnology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. n High Speed Data Acquisition Patents including 6140950, 6169506, 6411242, 6639526. TYPICAL APPLICATION LTC2442 Integral Non-Linearity High Precision Data Acquisition System 5 V = 2.048V 0.1F INCM 4 V = 4.096V REF V = 5V 4.5V TO 15V 4.5V TO 5.5V CC 3 + V = 5V = EXTERNAL OSCILLATOR V = 0V 2 + + = INTERNAL OSCILLATOR V V V F REF CC O (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 CH2 AUTO-CAL DIFFERENTIAL/ DIFFERENTIAL CS + 4-CHANNEL 2 24-BIT ADC SINGLE ENDED CH3 3 COM 4 V V REF GND LTC2442 2442 TA01 5 2.048 1.024 0 1.024 2.048 15V TO 0V 0.1F V DIFFERENTIAL (V) IN 2442 TA02 2442fb 1 For more information www.linear.com/LTC2442 INL ERROR (ppm)LTC2442 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Notes 1, 2) TOP VIEW Supply Voltage (V ) to GND ....................... 0.3V to 6V CC 1 36 SDO SCK Analog Input Pins Voltage 2 35 CS BUSY to GND ......................................0.3V to (V + 0.3V) CC 3 34 F EXT O Reference Input Pins Voltage 4 33 SDI DGND to GND ......................................0.3V to (V + 0.3V) CC 5 32 GND AGND Digital Input Voltage to GND .........0.3V to (V + 0.3V) CC 6 31 REF CH0 Digital Output Voltage to GND .......0.3V to (V + 0.3V) + CC 7 30 REF CH1 Operating Temperature Range 8 29 V CH2 CC LTC2442CG .................................................. 0C to 70C 9 28 COM CH3 LTC2442IG ...............................................40C to 85C 10 27 MUXOUTA ADCINB Storage Temperature Range .................. 65C to 150C 11 26 MUXOUTB ADCINA 12 25 +INA Lead Temperature (Soldering, 10 sec) ...................300C OUTA + 13 24 V INA Amplifier Supply Voltage (V to V ) ..........................36V 14 23 NC NC 15 22 NC NC 16 21 V+ NC 17 20 NC OUTB 18 19 +INB INB G PACKAGE 36-LEAD PLASTIC SSOP T = 125C, = 160C/W JMAX JA