Pulse duration (seconds)
Pulse duration (seconds)
Ratio to
rated power (％)
Ratio to
rated power (％)
These high-power low resistance chip resistors are designed to dissipate heat efficiently
through the land patterns on circuit boards. The actual temperature of the surface of the
resistor is dependent upon the dimensions and the shape of the land patterns.
Increase of the surface
temperature⊿T（℃）
0
0
20
40
60
80
100
120
160
180
200
220
5 10 15 20 25
RL3720W（Power rating 1Ｗ）
W（mm）
1W applied
0.75W
applied
0.5W applied
W
Chip resistors
L
(27mm)
Land pattern
Land area（S）＝Ｗ・Ｌ
Increase of the surface
temperature⊿T（℃）
0
0
20
40
60
80
100
120
160
180
200
220
5 10 15 20 25
RL7520W（Power rating 2Ｗ）
W（mm）
2W applied
1W applied
0.5W applied
W
Chip resistors
Land pattern
Land area（S）＝Ｗ・Ｌ
L
(27mm)
Increase of the surface
temperature⊿T（℃）
0
0
50
100
150
200
250
300
10 20 30
RL3720W（Power rating 0.5Ｗ）
L（mm）
0.5W applied
0.25W applied
W
（4.15mm）
Chip resistors
L
Land pattern
0
0
50
100
150
200
250
300
10 20 30
RL7520W（Power rating 1Ｗ）
Increase of the surface
temperature⊿T（℃）
L（mm）
1W applied
0.75W applied
0.5W applied
0.25W applied
W
（7.9mm）
Chip resistors
L
Land pattern
0.1
0
1
2
3
4
5
6
1 10 100
ESL(nH)
Frequency/MHz
group1：Distance between the two electrodes6.4ｍｍ（RL-3264）
group2：Distance between the two electrodes3.2ｍｍ（RL1632）
group3：Distance between the two electrodes1.6 ∼ 2.0ｍｍ（RL3720W）
group4：Distance between the two electrodes1.25ｍｍ（KRL2012）
Short
side
terminal
type
Long
side
terminal
type
Voltage pulse is applied to the test samples mounted
on the test board.
After each pulse, resistance drift is measured. Pulse
vol tage is increased until the drift exceeds +/-0.5%.
The power at that voltage is defined as the maximum
pulse power.
Test procedure
Pulse duration（seconds）
Maximum pulse power limit（W）
200
150
50
100
0
0.001 0.01 0.1 1 10
RL7520W-R10
RL3264-R050
RL7520-R10
RL1632-R050
RL1220-R10
100
50
0
−55 0 70 125
RL3720W
100
50
0
−55 0 30 150125
RL7520W
◆
Resistance to power pulse
◆
ESL (Equivalent series inductance)
◆
Surface temperature data
○
◆
Derating Curve
The high power type land pattern and
surface temperature
60
PRL / RL series
Current sensing surface mount resistors
