Datasheet

cui.com
date 11/07/2014 │ page 19 of 30CUI Inc │ SERIES: NQB-N │ DESCRIPTION: FULLY REGULATED ADVANCED BUS CONVERTERS
Layout recommendations
The radiated EMI performance of the product will
depend on the PWB layout and ground layer design.
It is also important to consider the stand-off of
the product. If a ground layer is used, it should
be connected to the output of the product and the
equipment ground or chassis.
A ground layer will increase the stray capacitance
in the PWB and improve the high frequency EMC
performance.
Output ripple and noise
Output ripple and noise measured according to gure
below.
Operating information
Power Management Overview
This product includes protection features that
continuously safeguard the load from damage due to
unexpected system faults.
Input Voltage
The NQB consists of two different product families
designed for two different input voltage ranges, 36 to
75 Vdc and 40 to 60 Vdc, see ordering information.
The input voltage range 36 to 75 Vdc meets the
requirements of the European Telecom Standard ETS
300 132-2 for normal input voltage range in –48 and
EMC Specification
Conducted EMI measured according to EN55022, CISPR
22 and FCC part 15J (see test set-up). The fundamental
switching frequency is 140 kHz for NQB at V
I
= 53 V, max
I
O
.
Conducted EMI Input terminal value (typ)
Optional external lter for class B
Suggested external input lter in order to meet class B in
EN 55022, CISPR 22 and FCC part 15J.
EMI without filter
L1
C1 C2 C3
C4
C5
R
-
+
Module
+
-
0
0
L2
Filter components:
C1 = 1 μF
C2 = 1 μF+220 μF
C3 = 1 μF+220 μF
C4,C5 = 2.2 nF
L1 = 810 μH
L2 = 810 μH
EMI with filter
Test set-up
Output ripple and noise test setup
For more information, please visit the product page.