1.1.4 The true RMS-to-DC conversion with ES636
If ES636 is used for true RMS-to-DC measurement, the test circuit is shown in Figure 1.
Make ADO and ADI pin short, and TEST5 pin keeps float. Connect OVSG pin to
AGND through a switch in ACV measurement mode.
ACV
AGND
+Vs -Vs
7
2
99.5
1K
10K
101K
1.111M
4.7u
+
1
2
3
4
5
6
7
14
13
12
11
10
9
8
+Vs
4
5
OVSG
OR1
VR5
VR4
VR3
VR2
TEST5
ACVL
ES51916
TL061
N1
1
100K
6
AGND
30K
3
N2
-Vs
4.7u
10
AGND
1.5K
-Vs
10K
AGND +Vs
0.1u
1M
ACVH
PWD
OP-
OP+
ADO
ADI
AGND
Note: The filter capacitors for +Vs and -Vs
are recommended to near to the power
terminals of ES636 and external OPAMP.
Figure 1. The true RMS-to-DC conversion with ES636
ES636
1K +Vs
500K
-Vs
AGND
5k 27k
10K
AGND
100K
3.3u
+
OPO
ADOHZ
AGND
v1.2
8
11/09/06
CYRUSTEK [ Cyrustek corporation ]
