Picor Corporation • picorpower.com
PI2161-EVAL1 User Guide Rev. 1.0 Page
4 of 8
Test Procedure:
Initial Test Set Up
PI2161-EVAL1 is configured for 48V ±10% input bus. The
current limit is set by the sense resistor R1. The sense
resistor is selected (120mΩ) for minimum worst case trip
current of 11.5A at 125°C.
Baseline Test Procedure – PI2161
(Refer to Figure 4)
1.
Recommended Material
1.1.
Material Needed-Picor supplied
1.1.1.
PI2161-EVAL1
1.1.2.
PI2161 Product Datasheet
1.2.
Recommended Users Supplied Equipment
1.2.1.
One DC power supply: 0-60V; 15A.
1.2.2.
One low power logic voltage power supply
1.2.3.
Load: electronic Load, Power resistors or
actual load.
1.2.4.
Multimeter.
1.2.5.
Oscilloscope.
1.2.6.
Appropriately sized interconnect cables.
1.2.7.
Safety glasses.
Before initial power-up follow these steps to configure
the evaluation board for specific end application
requirement:
2.
Sense resistor (Rs) selection
2.1.
In a typical load switch application the sense
resistor (Rs), R1 in the PI2161-EVAL1, is selected
based on a minimum trip current to allow
maximum
normal
load
current
without
interruption. The sense resistor value can be
determined from Overcurrent trip vs. sense
resistor chart in Figure 3:
Please refer to PI2161 Datasheet for more details on
how to calculate the sense resistor value verses trip
current.
Note:
Make sure that output capacitor inrush current is
less than two times the minimum set trip current.
Output capacitor inrush current is function of the
output capacitor value and output voltage rise time.
Figure 3:
PI2161 Overcurrent trip vs. sense resistor chart
40
50
60
70
80
90 100 110 120 130 140 150 160 170 180 190 200
8
10
12
14
16
18
20
22
24
26
28
30
32
Sense Resistor [mΩ]
Fo
rw
ar
d
O
ve
rc
u
rr
e
n
t
Tr
ip
[
A
]
Minimum Current trip [V
OC-THL
= 63mV; θ
J-A
= 125°C]
[V
OC-THL
= 63mV; θ
J-A
= 25°C]
Typical Current trip [V
OC-THL
= 70mV; θ
J-A
= 25°C]
Maximum Current trip [V
OC-THL
= 77mV; θ
J-A
= 25°C]