Motorola Professional GP640 Informacje o usłudze - Strona 8

Przeglądaj online lub pobierz pdf Informacje o usłudze dla Radio Motorola Professional GP640. Motorola Professional GP640 30 stron. Professional radio, power distribution and controller
Również dla Motorola Professional GP640: Podręcznik użytkownika (32 strony), Arkusz specyfikacji (2 strony), Informacje o usłudze (28 strony), Informacje o usłudze (32 strony), Informacje o usłudze (30 strony), Informacje o usłudze (26 strony), Informacje o usłudze (43 strony)

1-4

A MOSFET Q416 switches in the LiO supply when Vdd is removed. Q416 also provides isolation

from BOOT_CTRL function in the event of radio program flashing. The 3.3V regulator charges the

Lithium battery.

3.4

ModB/Vstby Supply

The supply to the ModB/Vstby pin varies depending on the conditions listed in Table 1-2.

Radio On

Radio Off

Primary battery removed

Flash Mode

3.5

Audio/Signalling Architecture

( Refer to Figure 1-2 and the ASFIC/ON_OFF and Audio Power Amplifier schematic diagrams )

The audio/signalling/filter/companding IC (ASFIC_CMP) and the audio power amplifier, shown in

Figure 1-2, form the main components of the audio/signalling architecture section of the controller

board. Inputs include a 16.8 MHz clock from the synthesizer, recovered audio and squelch, MCU

control signals, and external or internal microphones. Outputs include a microprocessor clock (uP),

modulator output to the synthesizer, and amplified audio signals to an internal or external speaker.

Table 1-2 ModB/Vstby Supply Modes

Condition

Circuit Operation

Vdd supply voltage via CR411

• Vdd turned off

• Q416 gate pulled low by R462

• Q416 switched on

• U410 supplies 3.2V to ModB/Vstby

• Vdd turned off

• Q416 gate pulled low by R462

• Q416 switched on

• Lithium battery provides 3.2V to ModB/Vstby

• Boot_Ctrl line pulled low

• ModA & ModB go low

• Processor in boot-strap mode

THEORY OF OPERATION