07/03/01

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ES5129

4-1/2 digit with LCD

Function Description

1. Normal Operation

When ES5129 operates at the oscillation frequency of 120KHz, the conversion period

will be 500ms. And the less frequency it has, the longer time it takes to complete one

conversion. ES5129 takes input signal from pins IN_LO and IN_HI differentially, and

takes reference from pins REF_LO and REF_HI. The typical reference voltage is about

1V. A filter capacitor and a protective resistor are recommended at IN_HI and IN_LO

terminal as the test circuit of page7.

2. Range Change Function

ES5129 has 2 operation ranges such as 200.00mV and 2.0000V. When the pin RANGE

is pulled to DGND or keep floating, ES5129 operates at 200.00mV full-scale range.

When it is pulled to V+, ES5129 change the input full-scale range to 2.0000V. And the

output data still remain the maximum counting number ±20,000.

3. Data Hold Function

ES5129 support a data hold function to stop the LCD panel upgrading and hold the

final data. When the pin HOLD keeps floating, ES5129 operates in free run mode, and

the data upgrades automatically after every conversion. When it is pulled to V+,

ES5129 enters HOLD mode, the LCD panel stops upgrading the output data, And the

final data before the HOLD mode is activated is held.

4. Decimal Points Controlled

ES5129 can drive 4 decimal points on LCD panel. It provides four pins DP1, DP2, DP3

and DP4 to control the decimal points. Connect these pins DP1~DP4 to V+ will turn on

the relative decimal point. To turn it off, keep DP pin float or connect it to DGND.

5. Continuity

An internal comparator with a 200mV threshold is connected directly between IN_LO

and IN_HI pins. The continuity output will be pulled high whenever the voltage

between the analog inputs is less than 200mV. And the “Continuity” annunciator on

LCD panel will be turned on. To disable the continuity function, connect the pin

continuity to DGND.