PAF600F280-28 TDK Corporation, PAF600F280-28 Datasheet - Page 29

• Manufacturer Part Number: PAF600F280-28
• Description: 28V@21.5A
• Manufacturer: TDK Corporation

・All specifications are subject to change without notice.
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4 Maximum Line Regulation
Maximum value of output voltage change when input volt-
age is gradually varied (steady state) within specified input
voltage range.
5 Maximum Load Regulation
Maximum value of output voltage change when output cur-
rent is gradually varied (steady state) within specified out-
put current range.
When using at dynamic load mode, audible noise could be
heard from the power module and output voltage fluctua-
tion might increase. A thorough pre-evaluation must be
performed before using this power module.
6 Over Current Protection (OCP)
This power module has built-in OCP function.
Output will recover when short circuit or overload condi-
tions are released. OCP setting value is fixed and there-
fore, cannot be externally adjusted.
Also, take note that power module might be damaged con-
tinuing output short circuit or over load conditions depend-
ing on thermal conditions.
7 Over Voltage Protection (OVP; OVP terminal)
This power module has built-in OVP function.
OVP set point is relative to the rated output voltage value.
When OVP is triggered, output can be recovered by turn-
ing input line off and then turning it on again after lowering
the input voltage below the voltage value indicated below,
or by manual reset of the control ON/OFF terminal. Reset
time for ON/OFF terminal is 100ms or longer.
When verifying OVP function by applying external voltage
at the output terminals, applied voltage value should not
exceed specified OVP maximum value. Refer to specifica-
tion table for OVP maximum value. Avoid applying external
voltage that exceeds OVP maximum value because this
will cause power module damage.
For 3.3V, 5V models, OVP setting value could be adjusted
as described below by external resistor connections. OVP
setting value for 12V, 28V models is fixed and cannot be
adjusted externally.
OVP setting adjustment method (for 3.3V, 5V models only)
For 3.3V, 5V models, when output voltage is set lower
than the typical output voltage rating, OVP setting value
can be adjusted by connecting external resistor (R3) be-
tween OVP terminal and –V terminal. When connecting
external resistor (R3) to the –V terminal, wiring should be
made such that the effect of voltage drop due to load cur-
rent is eliminated.
When there is no need to change OVP setting value, be
sure to leave the OVP terminal open.
OVP setting adjustment range is shown below.
OVP release input voltage value: 24VDC and below
500F48, 600F48, 700F48
Formula for determining OVP setting value (Vovp: TYP
value) by external resistor (R3) connection is shown below.
Vovp ： OVP Setting Value
Vref ： Internal Reference Voltage (TYP 1.225V)
r1, r2 ： Internal Output Voltage Detecting resistor
Also, formula for determining external resistor (R3) value
(TYP value) to set OVP voltage value (Vovp) arbitrarily
within the above range is shown below.
Graph representation of the above formulae is shown in fig.
7-2.
Resistor value calculated from this formula is a typical
value. When using this function verify that OVP functions
properly triggers at setting value by raising output voltage
using TRIM terminal, or by applying external voltage.
When using the remote sensing function, output voltage
at the output terminals of the power module generally be-
comes higher than the voltage at the load input terminals.
7
6
5
4
3
2
10
Fig.7-1 Example Connection of External Resistor
Vovp＝Vref・
R3＝
Fig.7-2 OVP Setting Voltage - R3 Resistor Value
r1
r2
2
(Refer to below table)
OVP
−V
−S
TRM
＋S
＋V
Table7-1 r1, r2 Resistor Value (TYP Value)
5V: 3.50V - 6.75V (70% - 135% )
3.3V: 2.60V - 4.785V (78.8% - 145% )
Vref・100・ （r1＋r2） −Vovp・r2・1100
OVP Setting Adjustment Range
10
R3
Vovp・r2− （r1＋r2） ・Vref
3
R3＋1100 r2
R3＋100
3.3V
8.2k
2.7k
(TYP Value)
R3 ( Ω )
10
・
4
r1＋r2
3.3V
Load
10
＋
−
6.8k
1.5k
5
5V
Unit： ［Ω］
5V
10
B-121
6
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