ES5106
3 1/2 DIGIT A/D CONVERTER W/LCD
The source current of COMMON is only 10μA, so it is easy to
pull COMMON voltage to a more negative voltage with respect to
the positive supply.
When the total supply voltage is large enough to cause the
zener to regulate(>7V), the COMMON voltage will have a low
temperature cofficient typically less than 60 ppm/℃. This voltage
can be used to generate the ES5106 reference voltage and an
external voltage reference will be unnecessary in most cases.
Reference Voltage
For a 1000 counts reading, the input signal must be equal to the
reference voltage. So for a 2000 counts full-scale reading, it requires
the input signal be twice the reference voltage. Thus, for the 200mV
and 2.000V full-scale, the reference voltage should equal 100.0mV
and 1.000V, In some applications the full-scale input voltage may be
other than 200mV or 2V, but 600mV, for example, The reference
voltage should be set to 300 mV and the input signal can be used
directly without being divided.
The differential reference can be used during the measurment
of resistor by the ratiometric method and when a digital reading of
zero is desired for VIN≠0. A compensating offset voltage can be
applied between COMMON and IN LO and the voltage of being
measured is connected between COMMON and IN HI.
03/05/14
10
CYRUSTEK [ Cyrustek corporation ]
