MAX1491, MAX1493, MAX1495 3.5- and 4.5-Digit, Single-Chip ADCs with LCD Drivers

3.5- and 4.5-Digit ADC, LED Display Drivers Reduce Time and Save Board Space

Status

Active: In Production.

Description

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The MAX1491/MAX1493/MAX1495 low-power, 3.5- and 4.5-digit, analog-to-digital converters (ADCs) with integrated liquid crystal display (LCD) drivers operate from a single 2.7V to 5.25V power supply. They include an internal reference, a high-accuracy on-chip oscillator, and a triplexed LCD driver. An internal charge pump generates the negative supply needed to power the integrated input buffer for single supply operation. The ADC is configurable for either a ��2V or ��200mV input range and it outputs its conversion results to an LCD. The MAX1491 is a 3.5-digit (��1999 count) device, and the MAX1493/MAX1495 are 4.5-digit (��19,999 count) devices.

The MAX1491/MAX1493/MAX1495 do not require external-precision integrating or auto-zero 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 differential signal and reference inputs, allowing direct interface with high-impedance signal sources. In addition, the MAX1491/MAX1493/MAX1495 use continuous internal offset calibration, and offer >100dB rejection of 50Hz and 60Hz line noise. The MAX1493/MAX1495 perform enhanced offset calibration at power-up. The MAX1495 also performs enhanced calibration on demand. Other features include data hold and peak hold, and a user programmable low-battery monitor.

The MAX1493/MAX1495 come in a 32-pin 7mm x 7mm TQFP package, and the MAX1491 comes in 28-pin SSOP and 28-pin DIP packages. All devices in this family operate over the 0��C to +70��C commercial temperature range.

An evaluation kit is available: MAX1493EVKIT

Key Features		Applications/Uses
High Resolution MAX1495: 4.5 Digits (��19,999 Count) MAX1493: 4.5 Digits (��19,999 Count) MAX1491: 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: Maximum 980µA Operating Current Small 32-Pin 7mm x 7mm TQFP Package (4.5 Digits), 28-Pin SSOP Package (3.5 Digits), and 28-Pin DIP Package (3.5 Digits) Triplexed LCD Driver Evaluation Kit Available (Order MAX1494EVKIT)		Digital Multimeters Digital Panel Meters Digital Voltmeters Handheld meters

Key Specifications: Dual-Slope & Display-Oriented ADCs

Part Number

Resolution
(��Counts)

Output Type

I_CC
(mA)

Ref.
(V)

V_SUPPLY
(V)

Oper. Temp.
(��C)

Package/Pins

Smallest Available Pckg.
(mm²)

Price

typ

max w/pins

See Notes

MAX1491

20000

LCD

Triplexed LCD

Int./Ext.

2.7 to 5.25

0 to +70

PDIP(N)/28

SSOP/28

289.5

$3.96 @1k

MAX1493

LQFP/32

82.8

$5.62 @1k

MAX1495

LQFP/32

82.8

$5.27 @5k

See All Dual-Slope & Display-Oriented ADCs (31)

Diagram

Typical Operating Circuit

source��ShenZhen henlito electronic co.,ltd.

web:www.henlito.com