ES636
True RMS-to-DC Converters
High-Accuracy Adjustments
The accuracy of the ES636 can be further improved by the external trimming scheme as
shown in Figure 4. The input should be grounded and R4 adjusted to give zero output
from pin 6. R1 and R2 are trimmed to give the correct value for a calibrated signal.
-
Cav
+
Vin
200
Ω
R1
1
V
IN
ABSOLUTE
VALUE
+Vs
14
+Vs
2
Enable
13
-Vs
3
-Vs
CAV
SQUARE
DIVIDER
12
4
11
5
dB
CURRENT
MIRROR
COMMON
10
R2
154
Ω
9
RL
+Vs
Vout
6
BUF out
+
BUF
-
7
BUF in
Iout
8
470
Ω
R3
R4
500K
Ω
-Vs
Figure 3. External Gain and Offset Trimming Circuit.
Power-Down Function
The ES636 provides a chip-enable pin (Pin 2). To enable the device, this pin must be
connected to –Vs. If it is connected to V+, the device will enter power-down mode. The
9
09/02/16
CYRUSTEK [ Cyrustek corporation ]
