User's Manual

APPLICANT: MOTOROLA, INC. FCC ID: IHDT6AC1

Exhibit 8

5. Design Consideration

5.1 Power supply considerations. Current requirements in each

mode.

5.2 Audio considerations.to refer to EV board chepter in

appendix.Car Kit connectionsl.

5.3 Data port considerations & Levels.

5.4 SIM card considarations.

5.5 ESD considerations.

5.6 Antenna

5.7 Software

5.8 Mechanical

5.1 Power supply consideration.

5.1.1 Power Supply losses.

The D15 is specified to operate from 3.0V to 6.0V. In order to

be able to work in the lowest battery values it is important

to verify the losses in the power supplies lines, Flat cable

and in the user PCB.

The D15 is a GSM phone that transmits in pulses of about 0.5mS

any 4mS. The Peak current is about 1.5A.

The VCC line will drop down in the TX periods:

In order to minimize the ∆ it is recommended to use a short

Flat cable as possible and to put a 1000uF capacitor (or

maximum possible) in the D15 VCC input.

5.1.2 Current consumption in D15:

In order to design the power supply correctly you need to take

in account the current consumption of the D15 in the different

Transmit

Periods

VCC