November 16, 2006
6881094C31-E
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3.2.5.3 Receive Audio Path
Refer to
. The receive audio data comes from the Abacus III IC U500 through the RF
interface connector P201 pin 12 (RX_DATA) to the Patriot IC SRDB pin. The DSP decodes the data
and sends it out through the CODEC_RX line to the GCAP II IC RX pin. The CODEC filters and
converts the digital data into an analog audio signal, which, in turn, is sent to a programmable gain
amplifier. The Patriot IC programs a multiplexer to route the audio signal to the A4 amplifier, which
has a fixed gain of 3.5 dB. The output of the A4 amplifier is pin EXTOUT.
From the EXTOUT pin, the audio signal goes through the pre-amplifier U502 and then to the audio
power amplifier U503, which together provide approximately 30 dB of gain. The Patriot IC selects
whether the amplified audio is routed to the internal speaker or the external speaker.
Figure 3-15. VOCON Receive Audio Path
3.2.5.4 Receive Audio Path (for NNTN5567A)
Refer to Figure 3-13a. The receive audio data comes from the Abacus III IC U500 through the RF
interface connector P201 pin 12 (RX_DATA) to the Patriot IC SRDB pin. The DSP decodes the data
and sends it out through the CODEC_RX line to the Mako IC VC_RX3V pin. The CODEC filters,
adds digital programmable gain G1, then converts the digital data into an analog audio signal, which
in turn is sent to programmable attenuator G3. The signal is then sent through an internal
programmable differential preamplifier (G4) to add gain and outputs the signal on pins VC_OUT_P
and VC_OUT_M of the Mako IC.
This output from the preamp is then filtered through circuitry R597, R598, C590, C565, C564, and
then sent back to 2 independent internal BTL differential power amplifiers, G5 & G6, of the Mako IC.
The power amplifiers are programmed to a fixed gain of 26 dB through the dual-core processor SPI
lines and PA control registers.
GCAP II IC U501
LP FILTER
cutoff = 3.5KHZ
HP FILTER
cutoff = 200HZ
GCAP CODEC
13-bit D/A
PGA
-35 to 0dB
in 5dB steps
Default 0dB
GCAP A4
Gain = 1.5
(3.5dB)
Audio_PA_Enable
0
0
1
1
Audio_Mode_Sel
0
1
0
1
Audio PA Status
Audio Off
Mute
Audio On
Audio On
Mode (V)
1.5V <V_mode<6V
<0.5V
>7V
PA Status
Mute
Audio On
Audio Off
Select (V)
B+ (7.5V)
<0.5V
Internal Speaker
Internal Speaker
External Speaker
ABACUS III
U500
(On RF Board)
RX_SSI_FSYNC
RX_SSI_CLK
RX_SSI_DATA
Audio PA Enable
Control circuits
1/2 Q505
Audio PA Mute
Control
Q506,R564,R559
Int/Ext SPKR SEL
Control circuits
1/2 Q505, R558
Flipper
U301
CODEC_FSYNC
PATRIOT
SAP/BBP
CODEC_RX
PATRIOT
SPI B
PATRIOT
GPIO
EXT PRE-AMP
U502
Gain set by
R537 and R551
AUDIO PA U503
Gain set by R550,
R554, R549, and
R553
MODE SELECT
External
Speaker
28 Ohm
Internal
Speaker
4
GCAP_CE, SCKB
SPI_MOSIB
SPI_MISOB
CODEC_DCLK
EXTOUT
TP212
TP2123
AUDIO_PA_ENABLE
AUDIO_MODE_SEL
EXT_SPKR_SEL
3
MAEPF-27417-A
Summary of Contents for ASTRO XTS-5000
Page 7: ...vi Table of Contents November 16 2006 6881094C31 E Notes ...
Page 11: ...x List of Figures November 16 2006 6881094C31 E Notes ...
Page 17: ...November 16 2006 6881094C31 E xvi CommercialWarranty Notes ...
Page 31: ...November 16 2006 6881094C31 E xxx Portable Radio Model Numbering System Notes ...
Page 83: ...November 16 2006 6881094C31 E 3 44 Theory of Operation Encryption Module ...
Page 135: ...November 16 2006 6881094C31 E 5 44 Troubleshooting Charts Secure Hardware Failure Notes ...
Page 175: ...November 16 2006 6881094C31 E 7 32 Troubleshooting Tables List of Board and IC Signals Notes ...
Page 367: ...November 16 2006 6881094C31 E Glossary 10 Notes ...
Page 373: ...Index 6 November 16 2006 6881094C31 E Notes ...