Motorola ASTRO XTS 5000 Detailed Service Manual page 60

3-22
3.2.3 Audio and Power
The audio and power section contains the following components:
• GCAP II IC U501
• 5 V regulator U505
• Audio pre-amplifier U502
• Audio power amplifier U503
• EEPOT U509
• 1.55 V regulator (NNTN4717 VOCON board only)
The GCAP II IC contains a CODEC, amplification, filtering, and multiplexing capability for receive
and transmit audio, voltage regulators, an analog-to-digital converter (ADC), and a real-time clock
(RTC). The GCAP II IC is programmed by the Patriot IC.
The audio pre-amplifier and the audio power amplifier condition the received audio signal before
being routed to the speaker. The dual EEPOT sets the gain of the microphone signal. These devices
are programmed by the Patriot IC.
NOTE: Refer to
of audio and power-related schematics that will aid in the following discussion.
3.2.3.1 GCAP II IC U501
The GCAP II IC is a mixed-signal (analog and digital) IC that provides control, audio, and voltage
regulation functionality. It comes in a 100-pin, ball-grid array (BGA) package with 0.8 mm pitch solder
balls. The GCAP II IC is supplied with switched battery voltage GCAP_B+ (R581).
3.2.3.1.1 Voltage Regulation
The GCAP II IC contains several voltage regulators that are used in the design of the VOCON board:
VSW1, VSW2, and V2. The VSW1 regulator is a programmable switching regulator that uses the
switched battery voltage as its input on pin PSRC1. The output voltage of VSW1 (R502) is
programmable by the Patriot IC U401 through the SPI bus. The initial output of VSW1 is 3.2 volts,
which is then programmed to 3.8 volts. The VSW1 voltage is supplied to the RF Interface connector
P201 pin 15 and to the input pins of the VSW2 and V2 regulators.
The VSW2 regulator is a SPI programmable switching regulator that uses VSW1 as its input on pin
PSRC2. The initial output of VSW2 (R501) is 2.2 volts, which is then programmed to 1.875 volts
(referred to as 1.8 volts throughout this document). The VSW2 voltage is supplied to the Patriot IC
(core voltage and the EIM voltage), the SRAM U403, the Flash memory U402, and the display
module connector J301 (1.8 V display interface only for the NTN9564 VOCON kit).
The V2 regulator is a SPI programmable linear regulator that uses VSW1 as its input on pin VIN2.
The initial output of V2 (R560) is 2.775 volts, which is then programmed to 3 volts for the NTN9564,
NNTN4563, and NNTN4819 VOCON boards, and 2.9 volts for the NNTN4717 VOCON board. The
V2 voltage is supplied to the Patriot IC (I/O ring - SPI, BBP, SAP, UART, GPIO, etc.), the Flipper IC
U301, the EEPOT U509, the display module connector J301, and the many discrete components
that interface with the Patriot IC and the Flipper IC.
July 21, 2004
Table 8-2, "List of VOCON Schematics and Board Overlays," on page 8-1
Theory of Operation
: VOCON Board
6881094C31-D
for a listing