User Guide

RM-11

System Module CC Technical Documentation

External Accessory Regulator

An external LDO Regulator is needed for accessory power supply purposes. All ACI acces-

sories require this power supply. A regulator input is connected to the battery voltage

VBAT and output is connected to the Vout pin in the Tomahawk connector. The regulator

ON/OFF function is controlled via the UPP.

The pull-down resistor on the enable input of the regulator is needed because in the

switch-off mode of the phone, the output level of the Genio(0) is not defined. If the

Genio(0) is floating, the regulator may be enabled when it should not be.

Figure 18: Accessory power supply diagram

PWB Strategy

PWB Construction

The PWB consists of a 6-layer board made up of FR4. Via types are through hole, laser,

buried, and blind vias. The PWB build up is shown in Figure 19:

Figure 19: RM-11 PWB build up

PWB Immunity

The PWB has been designed to shield all lines susceptible for radiation. Sensitive PWB

tracks have been drawn with respect to shielding by having ground plane over tracks,

and ground close to the tracks at the same layer.

Tomahawk btm conn

Voltage

regulator

3985

UPP

GenIO(0)

VBAT

VOUT

Solder resist 20 µm ± 10 µm

Finished copper 30 µm ± 10 µm

Dielectric Aramid 100 µm ± 20 µm

Finished copper 17 µm +2/-5 µm

Dielectric 150 µm ± 25 µm

Finished copper 17 µm +2/-5 µm

Dielectric 150 µm ± 25 µm

Finished copper 17 µm +2/-5 µm

Dielectric 150 µm ± 25 µm

Finished copper 17 µm +2/-5 µm

Dielectric Aramid 100 µm ± 20 µm

Finished copper 30 µm ±10 µm

Solder resist 20 µm ± 10 µm

Electromechanical Thickness with surface finish 1100um ±

110

Maximum thickness with solder resist 1270um