Q48SG12034NRFA Datasheet, PDF (8/26 Pages) Delta Electronics, Inc. – Delphi Series Q48SG Quarter Brick Family Full Digital Control DC/DC Power Modules:

DESIGN CONSIDERATIONS
Input Source Impedance
The impedance of the input source connecting to the
DC/DC power modules will interact with the modules and
affect the stability. A low ac-impedance input source is
recommended. If the source inductance is more than a
few μH, we advise adding a 100 to 200 μF electrolytic
capacitor (ESR < 0.7 Ω at 100 kHz) mounted close to the
input of the module to improve the stability.
Layout and EMC Considerations
Delta’s DC/DC power modules are designed to operate
in a wide variety of systems and applications. For design
assistance with EMC compliance and related PWB
layout issues, please contact Delta’s technical support
team. An external input filter module is available for
easier EMC compliance design. Below is the reference
design for an input filter tested with Q48SG120XXXXXX
to meet class B in CISSPR 22.
Schematic and Components List
For Single Module Application
Cin is 100uF low ESR Aluminum cap;
CX1 is 2.2uF ceramic cap×2pcs in parallel;
CX2 is 2.2uF ceramic cap;
CY1 and CY2 are 47nF ceramic cap;
CY is 3.3nF ceramic cap;
L1 and L2 are common-mode inductors, L1=L2=0.47mH;
Test Result: Vin=48V, Io=34A
dBμV
80.0
70.0
60.0
50.0
40.0
30.0
20.0
10.0
0.0
150 kHz
1 MHz
Limits
55022MQP
55022MAV
T ransducer
8130
T races
PK+
AV
10 MHz
30 MHz
For parallel application
Cin is 100uF low ESR Aluminum cap x 2pcs in parallel;
CX1 is 2.2uF ceramic cap×2pcs in parallel;
CX2 is 2.2uF ceramic cap;
CY1 is 47nF ceramic cap x 2pcs in parallel;
CY2 is 47nF ceramic cap x 2pcs in parallel;
CY is 3.3nF ceramic cap;
L1 is Pulse P0469NL (0.63mH/11.6A) x 2pcs in parallel;
L2 is Pulse P0469NL (0.63mH/11.6A) x 2pcs in parallel;
Test Result: Vin=48V, Io=68A
dBμV
80.0
70.0
60.0
Limits
55022MQP
55022MAV
50.0
40.0
30.0
20.0
T ransducer
8130
T races
PK+
AV
10.0
0.0
150 kHz
1 MHz
10 MHz
30 MHz
The blue line is quasi peak mode and the green one is
average mode.
8
DS_Q48SG12034_06272013