ES51931
22,000 Counts Auto DMM
1.1.2 CE selection
ES51931 has a CE selection feature archived by configuring a CESEL pin. If pin CESEL is connected to
V-, ES51931 will have a 610.0V overflow level in DCV and ACV ranges. If pin CESEL is connected to
DGND, the overflow level will be set to 1010V. When it is floating, the overflow level is set to 1500V in
DCV mode and 1010V in ACV mode. The meter will show OL when the measuring signal reaches the
overflow level. The configuration of CESEL is listed below.
CESEL
V-
DGND
Floating
1.1.3 HCF signal detection
DCV
610.0
1010.0V
1500.0V
ACV
610.0V
1010.0V
1010.0V
ES51931 provides detection of high-crest-factor (HCF) signal in ACV mode. When this
function is enabled, ES51931 senses the signal and determines it as HCF if the Vpp is
large enough. Once the signal is determined as HCF, ES51931 will jump up one
measuring range regardless of current measurement value. It takes 60ms to jump one
range up. The jumping up process will continue until the maximum range is reached.
With HCF detection, a more accurate result could be obtained. For example, when a
input signal with Vpeak=240V, Vrms=40V(CF=6) was applied, traditional DMMs
might stay at 22.000V range but shows counts with the amount of error up to 10% or
even bigger. The error rises from limited input/output swing at internal ADC. With HCF
detection, DMM will stay at 220.00V and exhibits more accurate results.
In addition to accuracy improvement, HCF will speed up the measuring process for
high voltage signals. For example, a 500Vrms is applied, ES51931 will take about
180ms (3 HCF jumps) to enter 1000.0 V range. And it takes 1 or 2 measuring processes
to obtain the stable result. Thus a stable LCD reading could be obtained within 1 sec.
Ver. 1.2
7
10/05/27
CYRUSTEK [ Cyrustek corporation ]
