Motorola Astro Xts5000 Detailed 6881094c31 E Manual

November 16, 20066881094C31-E
3-12Theory of Operation: Transceiver Board
3.1.3.9.1  Power and Control
Since U104 is powered from switched B+, it makes its own regulated 4.5 Vdc to power the internal 
logic. The supply input is V5EXT at pin 17, and the output is V45 at pin 16. RX at pin 23 is the control 
signal to the antenna switch control circuit.
3.1.3.9.2  Voltage Multiplier
The PCIC contains an internal voltage multiplier. This multiplier produces signal V10 (pin 14), a 10-V 
supply for the PCIC D/A...

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Theory of Operation: Transceiver Board3-13
The power level is set by programming an internal DAC to a calibrated reference voltage. D/A 
settings for the power set points were determined during radio tuning and stored in EEPROM. An 
internal op-amp compares the D/A reference voltage to the detector voltage at pin 1(RFIN) (TP101) 
and produces an error signal output. This signal is buffered by another op-amp, configured as a low-
pass filter, or integrator, to produce the INT...

November 16, 20066881094C31-E
3-14Theory of Operation: Transceiver Board
700–800 MHz: Three VCOs generate the first LO and transmit-injection signals.
NOTE:Refer to Table 8-1, “List of Transceiver Schematics and Board Overlays,” on page 8-1 for a 
listing of FGU-related schematics that will aid in the following discussion.
3.1.4.1  Reference Oscillator Y200
The radios frequency stability and accuracy derive from the Voltage-Controlled Temperature-
Compensated Crystal Oscillator (VCTCXO), Y200. This 16.8...

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3.1.4.2.4  Voltage Multiplier and Superfilter
Pins 12 (VMULT3) and 11 (VMULT4) together with diode arrays D201 and D202 and their associated 
capacitors form the voltage multiplier. The voltage multiplier generates 11.5 Vdc to supply the phase 
detector and charge-pump output stage at pin 47 (VCP).
The superfilter is an active filter that provides a low-noise supply for the VCOs and VCOBIC. The 
input is regulated 5 Vdc from Vdd5 at...

November 16, 20066881094C31-E
3-16Theory of Operation: VOCON Board
Transistors Q307 and Q310 form a 3.3 Vdc-to-5 Vdc logic-level shifter for the signal from the FracN 
AUX3 pin to the VCOBIC.
3.2 VOCON Board
This section provides a detailed circuit description of the ASTRO XTS 5000 VOCON board.
The VOCON board (Figure 3-7 and Figure 3-8) is divided into the following sections:
• Controller and Memory
• Audio and Power
• Interface Support
3.2.1 Interconnections
The VOCON board interconnection diagram (see...

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Figure 3-8.  VOCON Board Interconnections (only for NNTN5567)
The functional blocks consist of the following:
•Controller and Memory: The Patriot (U401), the dual-core processor with the microcontroller 
unit (MCU) and a digital signal processor (DSP), the SRAM (U403) and Flash (U402) memory 
devices.
•Audio and Power: The GCAP II (U501), a 5 Vdc linear regulator (U505), a 1.55 Vdc linear 
regulator (NNTN4717 VOCON kit only), the audio...

November 16, 20066881094C31-E
3-18Theory of Operation: VOCON Board
3.2.1.2  Encryption Connector J701
This 40-pin connector provides the interface between the VOCON board and the encryption module. 
Two voltages are provided to the encryption board: UNSWB+ and SWB+. The SAP SSI lines, serial 
communication data lines, and general-purpose I/O lines from the Patriot IC are included in the 
interface to the encryption board. A number of jumpers are present on some of the lines so that the 
VOCON board...

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Theory of Operation: VOCON Board3-19
NOTE:Refer to Table 8-2, “List of VOCON Schematics and Board Overlays,” on page 8-1 for a listing 
of VOCON schematics that will aid in the following discussion.
3.2.2.1  Patriot IC U401
The Patriot IC U401 is a dual-core processor that contains both a 32-bit microcontroller unit (MCU) 
and a 16-bit digital signal processor (DSP) in one IC package. It comes in a 256-pin, ball-grid array 
(BGA) package with 1mm pitch solder balls. On the...

November 16, 20066881094C31-E
3-20Theory of Operation: VOCON Board
The devices on the SPI A bus include the PCIC and FracN IC on the SPICS4 (R131), the Abacus III 
IC on SPICS5 (R126), an analog-to-digital converter (ADC) on SPICS6 (R133), and the serial 
EEPROM on SPICS7 (R132). The two SPI B chip selects are for the GCAP II IC U501 on SPICS2 
(R539) and the Flipper IC U301 on SPICS3. On the NNTN4563, NNTN4819, and NNTN4717 
VOCON boards, two additional SPI chip select lines are used for the display:...

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Theory of Operation: VOCON Board3-21
Serial Audio CODEC Port (SAP)
The Serial Audio CODEC Port (SAP) module is the DSP’s serial synchronous interface (SSI) to the 
audio CODEC on the GCAP II IC. However, In NNTN5567, the audio CODEC is on the MAKO IC. 
The SAP also interfaces with the encryption module.
The SAP interface consists of four signals including the SAP clock line pin SCKA (component R405 
or R572 (for NNTN5567) ), the SAP frame sync line pin SC2A (component R406...