1. >
  2. >

What are resistors?

Damage to thick-film resistors due to surges

Damage to thick-film resistors due to surges

Surges are large voltages (currents) instantaneously applied to circuits. Well-known examples include lightning and static electricity.
Surge voltage (current) applied to a resistor may affect the resistance characteristics due to excessive electrical stress or result in damage (worst-case scenario).

Schematic:Surge - Resistive material is damaged by load concentration, possibly resulting in resistance change.

Increasing surge resistance

One method for improving surge resistance is explained below.

  • Utilize materials with strong surge resistance
  • Increase the distance between electrodes, minimizing chip damage due to a smoother potential gradient.

Increasing the chip size will lengthen the distance between electrodes and provide greater surge resistance, but requires a larger mounting area.

For sets with insufficient board space requiring further miniaturization but need to protect against surges

Anti-surge chip resistors provide superior surge resistance in a compact size.

ESD Test (EIAJ Compliant) Human Body Model
Type Size Guaranteed Surge Resistance Value
ESR01 1005mm
(0402inch)
2kV
ESR03 1608mm
(0603inch)
3kV
ESR10 2012mm
(0805inch)
3kV
ESR18 3216mm
(1206inch)
3kV
ESR25 3225mm
(1210inch)
5kV
LTR10 2012mm
(0805inch)
3kV
LTR18 3216
(1206inch)
3kV
LTR50 5025mm
(2010inch)
3kV
LTR100 6432mm
(2512inch)
3kV

ROHM anti-surge chip resistors:

  1. Utilize materials that provide superior surge resistance
  2. Adopt a proprietary resistive element design that minimizes damage to the chip by providing a smooth potential gradient
Schematic:Differences Between Conventional and Anti-Surge Resistors - ROHM's anti-surge resistors feature a longer conduction path between electrodes, minimizing chip damage by smoothing out the potential gradient.
graph - Surge Resistance Characteristics Comparison ESD Test (EIAJ Compliant) Human Body Model

ROHM's anti-surge chip resistors feature improved the power handling characteristics and a revised element shape to achieve higher rated power than conventional types.

Size ESR Series MCR Series
1005 0.2W 0.063W
1608 0.25W 0.1W
2012 0.4W 0.125W
3216 0.33W 0.25W
3225 0.5W 0.25W
5025 - 0.5W

ROHM's ESR and LTR series provide improved surge-resistance characteristics and higher rated power while maintaining size.

Lineup

Part No. Size Rated Power
(70℃)
Maximum
Element
Voltage(V)
Resistance
Tolerance
Temperature Coefficient
of Resistance (ppm/℃)
Resistance Range Operating Temp. Range(℃) Automotive Qualified
(AEC-Q200)
SDRSeries
NewSDR03 1608 1/4W
(0.25W)
150 J(±5%) ±200 1~10MΩ(E24Series) -55~
+155
Yes
F(±1%) ±200
±100
1~9.76Ω(E24,96Series)
10~10MΩ(E24,96Series)
D(±0.5%) ±100 10~1MΩ(E24,96Series)
ESRSeries
ESR01 1005 1/5W
(0.2W)
50 J(±5%) +500/-250
±200
1Ω~9.1Ω(E24Series)
10Ω~10MΩ(E24Series)
-55~
+155
Yes
F(±1%) ±100 10Ω~976kΩ(E24,96Series)
1MΩ~2.2MΩ(E24Series)
ESR03 1608 1/4W
(0.25W)
150 J(±5%) ±200 1Ω~10MΩ(E24Series) Yes
F(±1%) ±200
±100
1Ω~9.76Ω(E24,96Series)
10Ω~10MΩ(E24,96Series)
D(±0.5%) ±100 10Ω~1MΩ(E24,96Series)
ESR10 2012 2/5W
(0.4W)
150 J(±5%) ±200 1Ω~30MΩ(E24Series) Yes
F(±1%) ±100 1Ω~10MΩ(E24,96Series)
D(±0.5%) ±100 10Ω~1MΩ(E24,96Series)
ESR18 3216 1/3W*1
(0.33W)
200 J(±5%) ±200 1Ω~15MΩ(E24Series) Yes
F(±1%) ±100 1Ω~10MΩ(E24,96Series)
D(±0.5%) ±100 10Ω~1MΩ(E24,96Series)
ESR25 3225 1/2W*1
(0.5W)
200 J(±5%) ±200 1Ω~10MΩ(E24Series) Yes
F(±1%) ±100 1Ω~10MΩ(E24,96Series)
D(±0.5%) ±100 10Ω~1MΩ(E24,96Series)
LTRSeries
LTR10 2012 1/4W
(0.25W)
150 J(±5%) ±200 1Ω~1MΩ (E24Series) -55~
+155
Yes
F(±1%) ±100 1Ω~1MΩ(E24,96Series)
D(±0.5%) ±100 10Ω~1MΩ(E24,96Series)
LTR18 3216 3/4W
(0.75W)
200 J(±5%) ±200 1Ω~1MΩ(E24Series) Yes
F(±1%) ±100 1Ω~1MΩ(E24,96Series)
D(±0.5%) ±100 10Ω~1MΩ(E24,96Series)
LTR50 5025 1W 200 J(±5%) ±200 1Ω~1MΩ(E24Series) Yes
F(±1%) ±100 1Ω~1MΩ (E24,96Series)
D(±0.5%) ±100 10Ω~1MΩ(E24,96Series)
LTR100 6432 2W 200 J(±5%) ±200 1Ω~1MΩ(E24Series) Yes
F(±1%) ±100 1Ω~1MΩ (E24,96Series)
D(±0.5%) ±100 10Ω~1MΩ(E24,96Series)

※E24:Standard Products/ E96:Custom Order Products

※Please contact a ROHM representative regarding commercial-grade products

Click here for inquiries concerning our products

Electronics
Fundamentals