EMC Specification
The conducted EMI measurement was performed using a module
placed directly on the test benchꢀ
The fundamental switching frequency is 195 kHz for
PKB 4711 PINB @ VI = 53V, IO = (0ꢀ1ꢀꢀꢀ1ꢀ0) x IOmaxꢀ
Printed Circuit Board
Power Module
5µH 50Ω
50 ohm temination
+
out
in
LISN
rcvr
DC
Filter
(if used)
Power
Source
Conducted EMI Input terminal value (typ)
5µH 50Ω
LISN
-
out
in
1 m Twisted Pair
rcvr
Resistive
Load
Optional Connection
to Earth Ground
50 ohm input
EMC
Reciver
Computer
Test set-up.
Layout Recommendation
The radiated EMI performance of the DC/DC converter will be opti-
mised by including a ground plane in the PCB area under the DC/DC
converterꢀ This approach will return switching noise to ground as
directly as possible, with improvements to both emissions and sus-
ceptibilityꢀ It is also important to consider the stand-off of the PKB
4000 series DC/DC converterꢀ If one ground trace is used, it should
be connected to the input returnꢀ Alternatively, two ground traces
may be used, with the trace under the input side of the DC/DC con-
verter connected to the input return and the trace under the output
side of the DC/DC converter connected to the output returnꢀ Make
sure to use appropriate safety isolation spacing between these two
return tracesꢀ The use of two traces as described will provide the
capability of routing the input noise and output noise back to their
respective returnsꢀ
EMI without filter
External filter (class B)
Required external input filter in order to meet class B in
EN 55022, CISPR 22 and FCC part 15Jꢀ
$ꢆ
-ꢂ
-ꢃ
ꢀ*O
ꢁ*O
ꢀ
ꢁ
$ꢅ
$ꢂ
$ꢃ
$ꢈ
$ꢄ
1,#
3
$ꢇ
Output ripple and noise
The circuit below has been used for the ripple and noise measure-
ments on the PKB 4000 Series DC/DC convertersꢀ
$ꢂꢉꢊꢃꢉꢊꢄꢋꢊꢌꢍꢆꢎꢊ¬'
$ꢈꢉꢊꢅꢋꢊꢆꢎꢊ¬'
$ꢆꢉꢊꢇꢋꢊꢃꢍꢃꢊO'
-ꢂꢋꢊꢇꢆꢎꢊ¬)
-ꢃꢋꢊꢅꢍꢆꢊ¬)
ꢊ
Ceramic
Capacitor
Tantalum
Capacitor
+Vout
+Sense
+
Trim
0.1uF
10uF
Load
-Sense
-Vout
BNC
Connector
to Scope
* Conductor from Vout to capacitors = 50mm [1.97in]
Output ripple and noise test setup
EMI with filter
EN/LZT 146 033 R9A ©Ericsson Power Modules, March 2007
37
PKB 4000 Datasheet
ERICSSON [ ERICSSON ]
