TDK-Lambda CHVM3 Series Instruction Manual page 9

■ Vref pin (standard voltage output)
When controlling the output voltage with an adjustable resistor, this pin is used. Vref has a standard output
voltage of 4V. In this case, the external adjustable resistor is 5KΩ. Since the resistance value from the external
adjustable resistor will decide the output voltage with the effect of the specified value, use a resistance value
with an accuracy of 5KΩ±5%. The type of resistor does not matter, as long as it is 5KΩ, however one with
a good temp coefficient is recommended.
■ Temperature derating
When using the product where the ambient temp is higher than 50°C, follow the derating graph below,
increasing the load resistance as the temp increases. The minimum load resistance value is specified for each
series.
■ Preventing reverse connections
The converter may break if the polarities are reversed. If there is a possibility in which the connections maybe
reversed, connect a diode and fuse like below.
■ Recommended solder conditions
Soldering conditions for each part are as follows:
(1) Soldering iron
(2) Dip solder bath
Standard voltage
generation circuit
CHVM
Vcont
Vref 4
External adjustable resistor (5.0K
Though the system may start , reliability is not guranteed.
100
80
60
40
(%)
20
0
-20 -10 0 +10 +20 +30 +40 +50 +60
Ambient temp (℃)
F1
+
12V
D1
340 ­ 360°C 5 seconds
230 ­ 260°C 10 seconds
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series
Vout (Com)
5
3
)
Ω
+Vin
CHVM
-Vin
TDK­Lambda
CHVM3 Series
INSTRUCTION MANUAL