MAX132 19-0009 Rev 2 8/95 18-Bit ADC with Serial Interface General Description Features The MAX132 is a CMOS, 18-bit plus sign, serial-output, Low Supply Current: analog-to-digital converter (ADC). Multi-slope integra- 60A (Normal Operation) tion provides high-resolution conversions in less time 1A (Sleep-Mode Operation) than standard integrating ADCs, allowing operation up 0.006% FSR Accuracy at 16 Conv/sec to 100 conversions per second. Low conversion noise provides guaranteed operation with 512mV full-scale Low Noise: 15V RMS input range (2V/LSB). A simple 4-wire serial interface Serial I/O Interface with Programmed Output for connects easily to all common microprocessors, and twos-complement output coding simplifies bipolar mea- Mux and PGA surements. Typical supply current is only 60A and is Performs up to 100 Conv/sec reduced to 1A in sleep mode. Four serially pro- grammed digital outputs can be used to control an 2pA Input Current external multiplexer or programmable-gain amplifier. 50Hz/60Hz Rejection The MAX132 comes in 24-pin narrow DIP and wide SO packages, and is available in commercial and extend- ed temperature grades. Ordering Information High resolution, compact size, and low power make this PART TEMP. RANGE PIN-PACKAGE device ideal for data loggers, weigh scales, data-acqui- MAX132CNG 0C to +70C 24 Narrow Plastic DIP sition systems, and panel meters. MAX132CWG 0C to +70C 24 Wide SO Applications MAX132C/D 0C to +70C Dice* Remote Data Acquisition MAX132ENG -40C to +85C 24 Narrow Plastic DIP Battery-Powered Instruments MAX132EWG -40C to +85C 24 Wide SO MAX132MRG -55C to +125C 24 Narrow CERDIP** Industrial Process Control * Contact factory for dice specifications. Transducer-Signal Measurement ** Contact factory for availability and processing to MIL-STD-883. Pressure, Flow, Temperature, Voltage Current, Resistance, Weight Functional Diagram Pin Configuration TOP VIEW CREF- CREF+ CS V+ 1 V+ +5V 24 602k CS DIN BUF OUT 2 23 BUF OUT SCLK DOUT INT OUT INT OUT 3 22 4.7nF EOC SCLK INT IN INT IN 4 21 DIN REF+ OSC2 MAX132 CREF- 5 20 DOUT REF- OSC1 6 19 CREF+ AGND P0 MAX132 REF+ 7 18 IN LO P0 P1 17 REF- 8 512mV INPUT IN HI P1 P2 16 AGND 9 P2 V- -5V DGND P3 P3 10 15 IN LO OSC1 OSC2 EOC IN HI 11 14 DGND 13 V- 12 DIP/SO Maxim Integrated Products 1 Call toll free 1-800-998-8800 for free samples or literature. EVALUATION KIT MANUAL FOLLOWS DATA SHEET18-Bit ADC with Serial Interface ABSOLUTE MAXIMUM RATINGS Supply Voltage Wide SO (derate 11.76mW/C above +70C)..............647mW V+ to DGND ..............................................-0.3V < V+ < +6.0V Narrow CERDIP (derate 12.50mW/C above +70C) ..688mW V- to DGND ................................................+0.3V < V- < -9.0V Operating Temperature Ranges V+ to V-............................................................................+15V MAX132C .......................................................0C to +70C Analog Input Voltage (any input).....................................V+ to V- MAX132E ....................................................-40C to +85C Digital Input Voltage .....................(DGND - 0.3V) to (V+ + 0.3V) MAX132MRG .................................................-55C to +125C Continuous Power Dissipation Storage Temperature Range .............................-65C to +160C Lead Temperature (soldering, 10sec) .............................+300C Narrow Plastic DIP (derate 8.70mW/C above +70C)....478mW Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V+ = 5V, V- = -5V, DGND = AGND = IN LO = REF- = 0V, REF+ = 545mV, R = 602k, C = 0.0047F, C = 0.1F, INT INT REF f = 32,768Hz, 60Hz mode, T = T to T , unless otherwise noted.) CLK A MIN MAX PARAMETER CONDITIONS MIN TYP MAX UNITS ACCURACY Resolution (Note 1) 18 Bits T = +25C 0 0.0076 A Zero Error V HI = 0V % of FSR IN T = T to T 0.0168 A MIN MAX Integral Nonlinearity (Notes 2, 3) T = +25C 0.0015 0.006 % of FSR A T = +25C 0 0.010 A Rollover Error (Note 4) % of FSR T = T to T 0.032 A MIN MAX Conversion Time f = 32.768Hz 63 ms CLK Input Voltage Range IN HI to IN LO, for specified accuracy 512 mV T = +25C 2 10 A Leakage Current IN HI, IN LO pA T = T to T 12 250 A MIN MAX V = 500mV 0.009 0.032 CM Common-Mode Rejection Ratio IN HI = IN LO % of FSR V = 3.0V 0.25 0.50 CM Common-Mode Range IN HI = IN LO 3.0 V Read-Zero 50Hz/60Hz Range 3.1 % of FSR RMS Noise T = +25C 15 V A Zero-Reading Drift (Note 3) 0.15 1.5 ppm/C Scale Factor Temp. Coefficient (Note 3) 5 ppm/C POWER REQUIREMENTS Positive Supply Voltage 4.5 5.5 V Negative Supply Voltage -5.5 -4.5 V T = +25C 0.003 0.0061 V HI = 400mV, V- = -5.0V, A IN Positive Supply Rejection % of FSR 4.5V V+ 5.5V T = T to T 0.003 0.0168 A MIN MAX T = +25C 0.003 0.0061 V HI = 400mV, V- = 5.0V, A IN Negative Supply Rejection % of FSR -5.5V V- -4.5V T = T to T 0.003 0.0168 A MIN MAX Positive Supply Current Digital input = 0V or V+ 60 125 A Negative Supply Current Digital input = 0V or V+ -35 -65 A Digital Ground Supply Current Digital input = 0V or V+ -25 -60 A Positive Sleep-Mode Current Digital input = 0V or V+ 110 A Negative Sleep-Mode Current Digital input = 0V or V+ -1 -10 A Digital Ground Sleep-Mode Digital input = 0V or V+ 02 A Current 2 MAX132