User Guide

LM960 HW Design Guide

1VV0301485 Rev. 15 Page 37 of 88 2020-08-13

In LTE/WCDMA/HSPA mode, the LM960 emits RF signals continuously during

transmission. Therefore, special attention must be paid on how to dissipate the heat

generated.

While designing the application board, special care must be taken by placing the LM960

module on a large ground area of the application board for effective heat dissipation.

Information – The LM960 must be connected to the ground and metal

chassis of the host board for best RF performance and thermal

dissipation.

 The two holes at the top of the module and the main ground

of the host board must be fastened together.

 The module shield and the host device main board or metal

chassis should be connected by means of conductive

materials.

4.3.3. Power Supply PCB layout Guidelines

As described in the electrical design guidelines, the power supply must have a low ESR

capacitor on the output to cut current peaks and a protection diode on the input to protect

the supply from spikes and polarity inversion. Placement of these components is crucial

for the correct operation of the circuitry: a misplaced component can be useless or can

even decrease the power supply performances.

 The bypass low ESR capacitor must be placed close to the LM960 power input

pins or - if the power supply is of a switching type - it can be placed close to the

inductor to reduce ripple, as long as the PCB trace from the capacitor to LM960 is

wide enough to ensure a drop-less connection even during the 2A current peaks.

 The protection diode must be placed close to the input connector where the power

source is drained.

 The PCB traces from the input connector to the power regulator IC must be wide

enough to ensure that no voltage drops occur during the 2A current peaks.

 The PCB traces to LM960 and the bypass capacitor must be wide enough to

ensure that no significant voltage drops occur when the 2A current peaks are

absorbed. This is needed for the same above-mentioned reasons. These traces

should be kept as short as possible.