
Chapter 3.4 700/800 MHz Radio Power
3.4.1 Introduction
This chapter of the manual provides a detailed circuit description of the power distribution for an
ASTRO XTS 2500/XTS 2500
I
digital portable radio. This manual is to be used in conjunction with the
ASTRO XTS 2500/XTS 2500
I
Digital Portable Radios Basic Service Manual (Motorola part number
6816984H01), which uses the pass/fail service approach to radio problems.
3.4.2 Radio Power Up or Down
Radio power up begins when the radio ON/OFF/Volume control knob is turned to the on position,
placing 7.5 volts on the MECH_SW line. This signal activates the pass element (Q700, Q701 and
Q703), enabling SW_B+ and .
When the MAKO IC (U701) detects a low to high voltage transition on the MECH_SW pin, it grounds
the FET_ENX pin (or VPP_EN) driving the gate of an external P-MOSFET (Q700 and Q703) low.
This turns ON the transistors Q700 and Q703 and applies SW_B+ to MAKO IC and VoCon and
to the RF section of the board. After application of the power to SW_B+, the regulators
VSW1, VSW2, V1.875, V1.55, V2.9 and VCC5 are sequenced on. After the regulators are stable, the
RESETX pin is asserted low for an additional 16ms and then de-asserted allowing the dual-core
processor to start.
The radio power down sequence begins by opening the radio ON/OFF switch, causing the
MECH_SW pin to transition high. This causes the MAKO IC to start an internal 125ms watchdog
timer and drive the INT_X pin (or MAKO_INT) interrupt output pin low. The dual-core processor then
determines (through communication on the SPI bus) that it must initiate the power-down sequence.
At this point, the watchdog timer can be kept alive by the dual-core processor (via the SPI bus)
allowing for software cleanup. Upon expiration of the watchdog timer, the MAKO IC asserts the
RESETX pin and turns off all DC regulators including SW_B+ and (Q700 and Q703 turn
off when the MAKO IC drives the FET_ENX pin high).
3.4.3 General
In the XTS 2500/XTS 2500
I
radio, power (B+) is distributed to one board that contains both the
transceiver and controller sections. There is an additional backup battery (Motorola part number
6003710K08) mounted directly on the board; see the basic service manual for details.
Power for the radio is provided through a battery supplying a nominal 7.5Vdc directly to the
transceiver. The battery is available in the following forms:
• NTN9815_ Nickel-Cadmium, Hi Capacity
• NTN9816_ Nickel-Cadmium, Hi Capacity, FM Approved
• NNTN9857_ Jedray NiMH Impres Standard Battery
• NNTN9858_ Jedray NiMH Impres FM Battery
• NNTN6263_ Jedray NiMH Impres FM Immersible Battery
B+ from the battery is electrically switched to most of the radio, rather than routed through the ON/
OFF/Volume control knob, S501. The electrical switching of B+ supports a “keep-alive” mode. Under
software control, even when the ON/OFF/Volume control knob has been turned to the “off” position,
power remains on until the MCU completes its power-down, at which time the radio is physically
powered-down.
Содержание ASTRO MT 1500
Страница 4: ...iv Table of Contents August 16 2007 6816985H01 B Notes ...
Страница 30: ...August 16 2007 6816985H01 B 2 1 4 VHF Overall Characteristics Vocoder Circuitry Overview Notes ...
Страница 34: ...August 16 2007 6816985H01 B 2 2 4 UHF1 Overall Characteristics Vocoder Circuitry Overview Notes ...
Страница 38: ...August 16 2007 6816985H01 B 2 3 4 UHF2 Overall Characteristics Vocoder Circuitry Overview Notes ...
Страница 42: ...August 16 2007 6816985H01 B 2 4 4 700 800 MHz Overall Characteristics Vocoder Circuitry Overview Notes ...
Страница 46: ...August 16 2007 6816985H01 B 2 5 4 900MHz Overall Characteristics Vocoder Circuitry Overview Notes ...
Страница 140: ...August 16 2007 6816985H01 B 4 4 20 700 800 MHz Detailed Theories of Operation VOCON Functional Blocks Notes ...
Страница 164: ...August 16 2007 6816985H01 B 5 6 Troubleshooting Procedures Operational Error Codes Notes ...
Страница 188: ...August 16 2007 6816985H01 B 6 1 24 VHF Troubleshooting Charts Secure Hardware Failure Notes ...
Страница 212: ...August 16 2007 6816985H01 B 6 2 24 UHF1 Troubleshooting Charts Secure Hardware Failure Notes ...
Страница 236: ...August 16 2007 6816985H01 B 6 3 24 UHF2 Troubleshooting Charts Secure Hardware Failure Notes ...
Страница 260: ...August 16 2007 6816985H01 B 6 4 24 700 800 MHz Troubleshooting Charts Secure Hardware Failure Notes ...
Страница 284: ...August 16 2007 6816985H01 B 6 5 24 900 MHz Troubleshooting Charts Secure Hardware Failure Notes ...
Страница 296: ...August 16 2007 6816985H01 B 7 1 12 VHF Troubleshooting Waveforms PP7 TX LO 7 1 11PP7 TX LO Probe point TP299 ...
Страница 301: ...6816985H01 B August 16 2007 VHF Troubleshooting Waveforms TP13 Mod In 7 1 17 7 1 16TP13 Mod In Test point TP36 ...
Страница 324: ...August 16 2007 6816985H01 B 7 1 40 VHF Troubleshooting Waveforms PP33 SPI Data 7 1 39PP33 SPI Data Probe Point R802 ...
Страница 325: ...6816985H01 B August 16 2007 VHF Troubleshooting Waveforms PP34 SPI CLK 7 1 41 7 1 40PP34 SPI CLK Probe Point R803 ...
Страница 342: ...August 16 2007 6816985H01 B 7 2 12 UHF1 Troubleshooting Waveforms PP7 TX LO 7 2 11PP7 TX LO Probe point TP299 ...
Страница 347: ...6816985H01 B August 16 2007 UHF1 Troubleshooting Waveforms TP13 Mod In 7 2 17 7 2 16TP13 Mod In Test point TP36 ...
Страница 371: ...6816985H01 B August 16 2007 UHF1 Troubleshooting Waveforms PP33 SPI Data 7 2 41 7 2 39PP33 SPI Data Probe Point R802 ...
Страница 372: ...August 16 2007 6816985H01 B 7 2 42 UHF1 Troubleshooting Waveforms PP34 SPI CLK 7 2 40PP34 SPI CLK Probe Point R803 ...
Страница 378: ...August 16 2007 6816985H01 B 7 2 48 UHF1 Troubleshooting Waveforms TP39 RX SSI Frame Sync Notes ...
Страница 390: ...August 16 2007 6816985H01 B 7 3 12 UHF2 Troubleshooting Waveforms PP7 TX LO 7 3 11PP7 TX LO Probe point TP299 ...
Страница 395: ...6816985H01 B August 16 2007 UHF2 Troubleshooting Waveforms TP13 Mod In 7 3 17 7 3 16TP13 Mod In Test point TP36 ...
Страница 418: ...August 16 2007 6816985H01 B 7 3 40 UHF2 Troubleshooting Waveforms PP33 SPI Data 7 3 39PP33 SPI Data Probe Point R802 ...
Страница 419: ...6816985H01 B August 16 2007 UHF2 Troubleshooting Waveforms PP34 SPI CLK 7 3 41 7 3 40PP34 SPI CLK Probe Point R803 ...
Страница 486: ...August 16 2007 6816985H01 B 7 5 12 Troubleshooting Waveforms PP7 TX LO 7 5 11PP7 TX LO Probe point Shield Tx_INJ ...
Страница 492: ...August 16 2007 6816985H01 B 7 5 18 Troubleshooting Waveforms TP13 Mod In 7 5 17TP13 Mod In Test point TP203 ...
Страница 501: ...6816985H01 B August 16 2007 Troubleshooting Waveforms PP22 Analog 5V 7 5 27 7 5 26PP22 Analog 5V Probe point U500 pin 5 ...
Страница 517: ...6816985H01 B August 16 2007 Troubleshooting Waveforms PP33 SPI Data 7 5 43 7 5 42PP33 SPI Data Probe Point R802 ...
Страница 518: ...August 16 2007 6816985H01 B 7 5 44 Troubleshooting Waveforms PP34 SPI CLK 7 5 43PP34 SPI CLK Probe Point R803 ...
Страница 521: ...6816985H01 B August 16 2007 Troubleshooting Waveforms TP37 RX SSI Data 7 5 47 7 5 46TP37 RX SSI Data Test Point TP403 ...
Страница 522: ...August 16 2007 6816985H01 B 7 5 48 Troubleshooting Waveforms TP38 RX SSI Clock 7 5 47TP38 RX SSI Clock Test Point TP404 ...
Страница 710: ...9 2 40 UHF1 Schematics Board Overlays and Parts Lists August 16 2007 6816985H01 B Notes ...
Страница 806: ...9 5 32 900MHz Schematics Board Overlays and Parts Lists August 16 2007 6816985H01 B Notes ...
Страница 816: ...Index 4 August 16 2007 6816985H01 B Notes ...
Страница 817: ......