Series Operation - TDK-Lambda PFH500 Series Instruction Manual

6.15 Series Operation

To increase the output voltage of a PFH Series module, it is possible to connect two or more PFH500 Series modules in
series. For two modules connected in series configuration, the connection diagrams are shown in Figure 6-10a and Figure 6-
10b. The output voltage from each module can be set (or trimmed) to different levels to form various combination of the total
output voltages. The RS(+) pin needs to be connected at local sense mode, i.e. to Vo(+) pin(s). Care must be taken when
using the ON-OFF feature in this configuration. Optocouplers or other isolated devices are needed. Contact TDK-Lambda
Customer Support for assistance.
Vout _ tot
RS (+)
Vo(+)
PFH500F
Vo(+)
Unit #1
Vo(-)
Vo(-)
RS (+)
Vo(+)
PFH500F
Vo(+)
Unit #2
Vo(-)
Vo(-)
Fig. 6-11a Series Operation #1 (Higher Output Voltage).
REV 2.8 (March 30, 2020)
 
Vout 1 Vout 2
+
Vout_1
Load
Vout_tot
Vout_2
-
(Formula 5-6)
RS (+)
Vo(+)
PFH500F
Vo(+)
Unit #1
Vo(-)
Vo(-)
RS (+)
Vo(+)
PFH500F
Vo(+)
Unit #2
Vo(-)
Vo(-)
Fig. 6-11b Series Connection #2 (Different Load with
Different Output Voltage).
TDK-Lambda
PFH500-SERIES
INSTRUCTION MANUAL
+
Vout_1 Load #1
-
+
Vout_2 Load #2
-
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