MAX1497 Datasheet, PDF (1/33 Pages) Maxim Integrated Products – 3.5- and 4.5-Digit, Single-Chip ADCs with LED Drivers and μC Interface

19-3054; Rev 1a; 2/04
3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
General Description
The MAX1497/MAX1499 low-power, 3.5- and 4.5-digit,
analog-to-digital converters (ADCs) with integrated light-
emitting diode (LED) drivers operate from a single 2.7V
to 5.25V power supply. They include an internal refer-
ence, a high-accuracy on-chip oscillator, and a multi-
plexed LED display driver. An internal charge pump
generates the negative supply needed to power the
integrated input buffers for single-supply operation. The
ADC is configurable for either a ±2V or ±200mV input
range and it outputs its conversion results to an LED
and/or to a microcontroller (µC). Microcontroller
communication is possible through an SPI™-/QSPI™-
/MICROWIRE™-compatible serial interface. The
MAX1497 is a 3.5-digit (±1999 count) device and the
MAX1499 is a 4.5-digit (±19,999 count) device.
The MAX1497/MAX1499 do not require external preci-
sion integrating capacitors, autozero capacitors, crystal
oscillators, charge pumps, or other circuitry required
with dual-slope ADCs (commonly used in panel meter
circuits).
These devices also feature on-chip buffers for the dif-
ferential signal and reference inputs, allowing direct
interface with high-impedance signal sources. In addi-
tion, they use continuous internal offset-calibration and
offer >100dB rejection of 50Hz and 60Hz line noise.
Other features include data hold and peak detection,
overrange and underrange detection, and a user-pro-
grammable low-battery monitor.
The MAX1499 is available in a 32-pin, 7mm ✕ 7mm
TQFP package and the MAX1497 is available in 28-pin
SSOP and 28-pin PDIP packages. All devices in this
family operate over the -40°C to +85°C extended tem-
perature range.
Digital Panel Meters
Hand-Held Meters
Digital Voltmeters
Digital Multimeters
Applications
Features
♦ High Resolution
MAX1499: 4.5 Digits (±19,999 Count)
MAX1497: 3.5 Digits (±1999 Count)
♦ Sigma-Delta ADC Architecture
No Integrating Capacitors Required
No Autozeroing Capacitors Required
>100dB of Simultaneous 50Hz and 60Hz
Rejection
♦ Operate from a Single 2.7V or 5.25V Supply
♦ Selectable Input Range of ±200mV or ±2V
♦ Selectable Voltage Reference: Internal 2.048V or
External
♦ Internal High-Accuracy Oscillator Needs No
External Components
♦ Automatic Offset Calibration
♦ Low Power (Exclude LED Driver Current)
Maximum 664µA Operating Current
Maximum 268µA Shutdown Current
♦ Small 32-Pin, 7mm x 7mm TQFP Package (4.5
Digits), 28-Pin SSOP Package (3.5 Digits)
♦ Also Available in a PDIP Package (3.5 Digits)
♦ Multiplexed LED Drivers
Resistor-Programmable Segment Current
♦ SPI-/QSPI-/MICROWIRE-Compatible Serial
Interface
♦ Extended Temperature Range (-40°C to +85°C)
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
RESOLUTION
(DIGITS)
MAX1497EAI* -40°C to +85°C 28 SSOP
3.5
MAX1497EPI -40°C to +85°C 28 PDIP
3.5
MAX1499ECJ -40°C to +85°C 32 TQFP
4.5
*Future product—contact 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.
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