Voltage Regulation; Emergency; Front And Rear Connectors - Motorola ASTRO XTL 5000 Basic Service Manual

3-4
NOTE: A control head is not necessary for the function of the radio (in special application
configurations), but the controller section is critical for the RF sections to function. This is an
important point since repairs and troubleshooting of the RF sections usually requires that the
controller section is operating correctly.
3.5.2

Voltage Regulation

The uniboard contains the following voltage regulators: 9 V, 5 V, 3 V, 2.85 V, 1.85 V, and 1.55 V.
The radio's A+ supply is regulated down to additional supplies for various blocks (frequency
generation unit (FGU), receiver, transmitter power amplifier, and controller). Specifically, A+ is used
to regulate three separate 9.3-volt supplies, one for the FGU and receiver circuitry, one for the
transmitter power amplifier circuitry, and one for the controller sections.
• The FGU and receiver circuitry use the 9.3-volt supply to further regulate a common 5-volt
supply and two separate 3-volt supplies, one for the FGU and one for the Abacus III IC.
• The transmitter power amplifier uses its 9.3-volt supply directly for its pre-amplifier and to a 3-
volt supply for most of the ALC (automatic level control).
• The controller uses the 9.3-volt supply to power the microphone, part of a RS232 translator,
and to provide voltage to the 5-volt regulator, which supplies the 2.85 V, 1.85 V, and 1.55 V
supplies.
- The 2.85-volt regulator supplies most of the digital logic circuitry on the controller, as well as
the I/O of the microprocessor.
- The 1.85-volt regulator supplies the FLASH and SRAM circuitry.
- The 1.55-volt regulator supplies the core of the microprocessor.
3.5.3

Emergency

Circuity exists to support emegency switch operation. While the radio is ON, emergency can be
activated to alert dispatch.
NOTE: This feature is either visual or can be set to covert, and is programmable through the CPS
(customer programming software). This functionality is dependent on CPS version and
customer demand for feature availability.
3.5.4

Front and Rear Connectors

The surrounding controller section contains the front and rear connections to allow interfacing with
existing and future accessories.
These custom connectors are optimized to meet voltage and current requirements for existing
accessories and for the compatible flexes that are used with the XTL 5000 radio.
NOTE: It is not recommended to insert non-Motorola parts or flexes into these connectors.
June 13, 2003
Basic Theory of Operation: Surrounding Controller Region
6881096C73-O