pth12050 Astec Powe, pth12050 Datasheet - Page 9

• Manufacturer Part Number: pth12050
• Description: Pth05020 5vin Single
• Manufacturer: Astec Powe

7.5 Remote Sense
The PTHxx010W, PTHxx020W, and PTHxx030W products
incorporate an output voltage sense pin, V
pin should be connected to V
standard application). A remote sense improves the load regulation
performance of the module by allowing it to compensate for any ‘IR’
voltage drop between itself and the load. An IR drop is caused by
the high output current flowing through the small amount of pin and
trace resistance. Use of the remote sense is optional. If not used, the
Vout Sense pin can be left opencircuit. An internal low-value resistor
(15Ω or less) is connected between the V
that the output voltage remains in regulation.
With the sense pin connected, the difference between the voltage
measured directly between the V
measured from V
compensated by the regulator. This should be limited to a maximum
of 0.3V.
Note: The remote sense feature is not designed to compensate for
the forward drop of non-linear or frequency dependent components
that may be placed in series with the converter output. Examples
include OR-ing diodes, filter inductors, ferrite beads, and fuses.
When these components are enclosed by the remote sense
connection they are effectively placed inside the regulation control
loop, which can adversely affect the stability of the regulator.
Figure 11 - Margin Up/Down Application Schematic
GND
MargUp
V
MargDown
in
C
in
+
out sense
Q
R
1
D
Q
R
to GND, is the amount of IR drop being
2
u
1
2
out
File Name: an_pth05020.pdf Rev (05): 21 Dec 2005
at the load circuit (see datasheet
out
and GND pins, and that
PTH05020
(Top View)
10
3
9
4
o
8
5
R
o
Sense and V
SET
Sense. The V
0.1W, 1%
7
6
out
C
+V
0V
out
o
, ensures
o
Sense
+
GND
+V
out
L
O
A
D
Application Note 156
8. Thermal Information
8.1 Thermal Reference Points
The electrical operating conditions namely:
• Input voltage, V
• Output voltage, V
• Output current, I
determine how much power is dissipated within the converter. The
following parameters further influence the thermal stresses
experienced by the converter:
• Ambient temperature
• Air velocity
• Thermal efficiency of the end system application
• Parts mounted on system PCB that may block airflow
• Real airflow characteristics at the converter location
8.2 Safe Operating Area Curves
Thermal characterisation data is presented in the datasheet in a safe
operating area curve format which is repeated here in Figure 12.
This SOA curve shows the load current versus the ambient air
temperature and velocity.
www.artesyn.com
90
80
70
60
50
40
30
20
0 2
Figure 12 - Safe Operating Curve
4
OUTPUT CURRENT (A)
in
o
o
6
PTH05020W V out = 3.3V
8 10 12
14
16 18 20 22
Nat conv
100 LFM
200 LFM
400 LFM
9