MAX1491/MAX1493/MAX1495 19-3053 Rev 2 5/04 3.5- and 4.5-Digit, Single-Chip ADCs with LCD Drivers General Description Features The MAX1491/MAX1493/MAX1495 low-power, 3.5- and High Resolution 4.5-digit, analog-to-digital converters (ADCs) with inte- MAX1495: 4.5 Digits (19,999 Count) grated liquid crystal display (LCD) drivers operate from a MAX1493: 4.5 Digits (19,999 Count) single 2.7V to 5.25V power supply. They include an inter- MAX1491: 3.5 Digits (1999 Count) nal reference, a high-accuracy on-chip oscillator, and a Sigma-Delta ADC Architecture triplexed LCD driver. An internal charge pump generates the negative supply needed to power the integrated input No Integrating Capacitors Required buffer for single supply operation. The ADC is config- No Autozeroing Capacitors Required urable for either a 2V or 200mV input range and it out- >100dB of Simultaneous 50Hz and 60Hz Rejection puts its conversion results to an LCD. The MAX1491 is a Operate from a Single 2.7V or 5.25V Supply 3.5-digit (1999 count) device, and the MAX1493/ MAX1495 are 4.5-digit (19,999 count) devices. Selectable Input Range of 200mV or 2V The MAX1491/MAX1493/MAX1495 do not require exter- Selectable Voltage Reference: Internal 2.048V or nal-precision integrating or auto-zero capacitors, crystal External oscillators, charge pumps, or other circuitry required with dual slope ADCs (commonly used in panel meter Internal High-Accuracy Oscillator Needs No circuits). These devices also feature on-chip buffers for External Components the differential signal and reference inputs, allowing Automatic Offset Calibration direct interface with high-impedance signal sources. In addition, the MAX1491/MAX1493/MAX1495 use continu- Low Power: Maximum 980A Operating Current ous internal offset calibration, and offer >100dB rejec- Small 32-Pin 7mm 7mm TQFP Package (4.5 tion of 50Hz and 60Hz line noise. The MAX1493/ Digits), 28-Pin SSOP Package (3.5 Digits), and 28- MAX1495 perform enhanced offset calibration at power- Pin DIP Package (3.5 Digits) up. The MAX1495 also performs enhanced calibration on demand. Other features include data hold and peak Triplexed LCD Driver hold, and a user programmable low-battery monitor. Evaluation Kit Available (Order MAX1494EVKIT) The MAX1493/MAX1495 come in a 32-pin 7mm 7mm TQFP package, and the MAX1491 comes in 28-pin SSOP and 28-pin DIP packages. All devices in this fam- Pin Configurations ily operate over the 0C to +70C commercial tempera- ture range. TOP VIEW 32 31 30 29 28 27 26 25 Applications AV 1 24 SEG13 Digital Panel Meters DD AIN+ 2 23 SEG12 Hand-Held Meters 22 SEG11 AIN- 3 Digital Voltmeters REF- 4 21 SEG10 Digital Multimeters MAX1493 REF+ 5 20 SEG9 MAX1495 LOWBATT 6 19 SEG8 Ordering Information RANGE 7 18 SEG7 TEMP PIN- RESOLUTION DPSET1 8 17 SEG6 PART RANGE PACKAGE (DIGITS) 9 10 11 12 13 14 15 16 MAX1491CAI 0C to +70C 28 SSOP 3.5 MAX1491CNI 0C to +70C 28 DIP 3.5 MAX1493CCJ 0C to +70C 32 TQFP 4.5 TQFP MAX1495CCJ 0C to +70C 32 TQFP 4.5 Pin Configurations continued at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLE GND DPSET2 PEAK DV DD HOLD INTREF SEG1 V NEG SEG2 DPON SEG3 BP1 SEG4 BP2 SEG5 BP33.5- and 4.5-Digit, Single-Chip ADCs with LCD Drivers ABSOLUTE MAXIMUM RATINGS AV to GND............................................................-0.3V to +6V Continuous Power Dissipation (T = +70C) DD A DV to GND ...........................................................-0.3V to +6V 32-Pin TQFP (derate 20.7mW/C above +70C).....1652.9mW DD AIN+, AIN- to GND...............................V to + (AV + 0.3V) 28-Pin SSOP (derate 9.5mW/C above +70C) ...........762mW NEG DD REF+, REF- to GND..............................V to + (AV + 0.3V) 28-Pin DIP (derate 14.3mW/C above +70C)........1142.9mW NEG DD LOWBATT to GND ...................................-0.3V to (AV + 0.3V) Operating Temperature Range...............................0C to +70C DD INTREF, RANGE, DPSET1, DPSET2, PEAK, Junction Temperature......................................................+150C HOLD to GND......................................-0.3V to (DV + 0.3V) Storage Temperature Range .............................-60C to +150C DD DPON to GND..........................................-0.3V to (DV + 0.3V) Lead Temperature (soldering, 10s) .................................+300C DD V to GND ...........................................-2.6V to (AV + 0.3V) NEG DD Maximum Current into Any Pin ...........................................50mA 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 (AV = DV = +2.7V to +5.25V, GND = 0, V - V = 2.048V (external reference), C = 0.1F. All specifications are T DD DD REF+ REF- NEG MIN to T , unless otherwise noted. Typical values are at +25C, unless otherwise noted.) MAX PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC ACCURACY MAX1493/MAX1495 -19,999 +19,999 Noise-Free Resolution Count MAX1491 -1999 +1999 2.000V range 1 Integral Nonlinearity (Note 1) INL Count 200mV range 1 (V - V = 0.100V) on 200mV range / AIN+ AIN- Range Change Accuracy 10:1 Ratio (V - V = 0.100V) on 2.0V range AIN+ AIN- V - V = full scale, AIN+ AIN- Rollover Error 1.0 Count V - V = full scale AIN- AIN+ Output Noise 10 V P-P Offset Error (Zero Input Reading) Offset V = 0 (Note 2) -0 +0 Reading IN Gain Error (Note 3) -0.5 +0.5 %FSR Offset Drift (Zero Reading Drift) V = 0 0.1 V/C IN Gain Drift 1 ppm/C INPUT CONVERSION RATE Conversion Rate 5Hz ANALOG INPUTS (AIN+, AIN-) (bypass to GND with 0.1F or greater capacitors) RANGE = GND -2.0 +2.0 Differential (Note 4) AIN Input Voltage Range RANGE = DV -0.2 +0.2 V DD Absolute GND referenced -2.2V +2.2V Normal Mode 50Hz and 60Hz 50Hz and 60Hz 2% 100 dB Rejection (Simultaneously) Common-Mode 50Hz and 60Hz For 50Hz 2% and 60Hz 2%, CMR 150 dB Rejection (Simultaneously) R < 10k SOURCE Common-Mode Rejection CMR At DC 100 dB Input Leakage Current T = +25C10nA A Input Capacitance 10 pF Dynamic Input Current (Note 5) -20 +20 nA 2 MAX1491/MAX1493/MAX1495