MAX1497/MAX1499 19-3054 Rev 1a 2/04 3.5- and 4.5-Digit, Single-Chip ADCs with LED Drivers and C Interface General Description Features The MAX1497/MAX1499 low-power, 3.5- and 4.5-digit, High Resolution analog-to-digital converters (ADCs) with integrated light- MAX1499: 4.5 Digits (19,999 Count) emitting diode (LED) drivers operate from a single 2.7V MAX1497: 3.5 Digits (1999 Count) to 5.25V power supply. They include an internal refer- Sigma-Delta ADC Architecture ence, a high-accuracy on-chip oscillator, and a multi- No Integrating Capacitors Required plexed LED display driver. An internal charge pump No Autozeroing Capacitors Required generates the negative supply needed to power the >100dB of Simultaneous 50Hz and 60Hz integrated input buffers for single-supply operation. The Rejection ADC is configurable for either a 2V or 200mV input Operate from a Single 2.7V or 5.25V Supply range and it outputs its conversion results to an LED and/or to a microcontroller (C). Microcontroller Selectable Input Range of 200mV or 2V communication is possible through an SPI-/QSPI- Selectable Voltage Reference: Internal 2.048V or /MICROWIRE-compatible serial interface. The External MAX1497 is a 3.5-digit (1999 count) device and the Internal High-Accuracy Oscillator Needs No MAX1499 is a 4.5-digit (19,999 count) device. External Components The MAX1497/MAX1499 do not require external preci- Automatic Offset Calibration sion integrating capacitors, autozero capacitors, crystal oscillators, charge pumps, or other circuitry required Low Power (Exclude LED Driver Current) with dual-slope ADCs (commonly used in panel meter Maximum 664A Operating Current circuits). Maximum 268A Shutdown Current These devices also feature on-chip buffers for the dif- Small 32-Pin, 7mm x 7mm TQFP Package (4.5 ferential signal and reference inputs, allowing direct Digits), 28-Pin SSOP Package (3.5 Digits) interface with high-impedance signal sources. In addi- Also Available in a PDIP Package (3.5 Digits) tion, they use continuous internal offset-calibration and Multiplexed LED Drivers offer >100dB rejection of 50Hz and 60Hz line noise. Resistor-Programmable Segment Current Other features include data hold and peak detection, overrange and underrange detection, and a user-pro- SPI-/QSPI-/MICROWIRE-Compatible Serial grammable low-battery monitor. Interface The MAX1499 is available in a 32-pin, 7mm 7mm Extended Temperature Range (-40C to +85C) TQFP package and the MAX1497 is available in 28-pin SSOP and 28-pin PDIP packages. All devices in this family operate over the -40C to +85C extended tem- perature range. Applications Ordering Information Digital Panel Meters PIN- RESOLUTION PART TEMP RANGE PACKAGE (DIGITS) Hand-Held Meters MAX1497EAI* -40C to +85C 28 SSOP 3.5 Digital Voltmeters MAX1497EPI -40C to +85C 28 PDIP 3.5 Digital Multimeters MAX1499ECJ -40C to +85C 32 TQFP 4.5 *Future productcontact factory for availability. Pin Configurations appear at end of data sheet. SPI/QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp. 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.3.5- and 4.5-Digit, Single-Chip ADCs with LED Drivers and C Interface ABSOLUTE MAXIMUM RATINGS AV to GND (MAX1499).........................................-0.3V to +6V VLED to GLED..........................................................-0.3V to +6V DD DV to GND (MAX1499) ........................................-0.3V to +6V GLED to GND........................................................-0.3V to +0.3V DD AIN+, AIN- to GND (MAX1499) ...........VNEG to (AV to +0.3V) SEG to GLED..........................................-0.3V to (VLED + 0.3V) DD REF+, REF- to GND (MAX1499)......... VNEG to (AV to +0.3V) DIG to GLED ..........................................-0.3V to (VLED + 0.3V) DD LOWBATT to GND (MAX1499) ................-0.3V to (AV + 0.3V) DIG Sink Current .............................................................300mA DD CLK, EOC, CS, DIN, SCLK, DIG Source Current...........................................................50mA DOUT to GND (MAX1499).......................-0.3V to (DV + 0.3V) SEG Sink Current ..............................................................50mA DD VNEG to GND (MAX1499) .......................-2.6V to (AV + 0.3V) SEG Source Current..........................................................50mA DD LED EN to GND (MAX1499)....................-0.3V to (DV + 0.3V) Maximum Current Input into Any Other Pin ........................50mA DD ISET to GND (MAX1499)..........................-0.3V to (AV + 0.3V) Continuous Power Dissipation (T = +70C) DD A V to GND (MAX1497)...........................................-0.3V to +6V 32-Pin TQFP (derate 20.7mW/C above +70C).....1652.9mW DD AIN+, AIN- to GND (MAX1497)..............VNEG to (V to +0.3V) 28-Pin SSOP (derate 9.5mW/C above +70C) ...........762mW DD REF+, REF- to GND (MAX1497) ........... VNEG to (V to +0.3V) 28-Pin PDIP (derate 14.3mW/C above +70C)......1142.9mW DD CLK, EOC, CS, DIN, SCLK, Operating Temperature Range ...........................-40C to +85C DOUT to GND (MAX1497)..........................-0.3V to (V + 0.3V) Junction Temperature......................................................+150C DD VNEG to GND (MAX1497)..........................-2.6V to (V + 0.3V) Storage Temperature Range .............................-60C to +150C DD ISET to GND (MAX1497) ............................-0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C DD 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 = V = +2.7V to +5.25V, GND = 0, GLED = 0, V = +2.7V to +5.25V, V - V = 2.048V (external reference) DD DD DD LED REF+ REF- C = C = 0.1F, C = 0.1F. Internal clock mode, unless otherwise noted. All specifications are at T = T to T . REF+ REF- VNEG A MIN MAX Typical values are at T = +25C, unless otherwise noted.) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC ACCURACY MAX1499 -19,999 +19,999 Noise-Free Resolution Count MAX1497 -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 Ratio 10:1 Ratio (V - V = 0.100V) on 2.0V range AIN+ AIN- V - V = full scale AIN+ AIN- Rollover Error 1 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 (Note 4) 0.1 V/C IN Gain Drift 1 ppm/C INPUT CONVERSION RATE External-Clock Frequency 4.9152 MHz External-Clock Duty Cycle 40 60 % Internal clock 5 Conversion Rate Hz External clock, f = 4.9152MHz 5 CLK 2 MAX1497/MAX1499