High Current Jumper Chip

LRZ Series

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Issue B · 02.05

Application Notes

Conventional thick film “zero-Ohm” jumper chips typically

have up to 50mΩ resistance values and 1 to 2A current

ratings. LRZ jumper chips offer a solution for currents over an

order of magnitude greater by combining lower resistance

values with better thermal conductivity.

Care should be taken when designing the associated printed

circuit board tracks to ensure that they can carry the required

current without excessive heating, for example by using

multiple layers thermally linked with many vias. Any

temperature rise caused by power dissipated in the PCB tracks

themselves should be allowed for when calculating the

ambient temperature in order to determine whether power

de-rating should be applied. The minimum recommended pad

and trace areas close to the resistor stated under Electrical

Data should be provided at each terminal. For multi-layer

PCB’s, this minimum area requirement should be met by

surface layers rather than buried layers. The actual solder pad

area follows the normal design rules for chip resistors.

LRZ jumper chips themselves can operate at a maximum

temperature of 150˚C (see performance above). For

conventionally soldered jumper chips, the joint temperature

should not exceed 110˚C. This condition is met when the

stated current levels at 70˚C are used.

100%

80%

120%

60%

40%

20%

0%

0

50

100

150

Derating Characteristic

Ambient Temperature (˚C)

1000

10

0.1

1

10

100

1000

Pulse Duration (ms)

100

Continuous Pulse Performance

LRZ1206

LRZ2010

LRZ2512

Temperature Derating

Pulse Performance

Welwyn Components

Welwyn Components

LRZ_B.qxd

2/16/05

3:49 PM

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