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14
BB-HCM547A
4.4.
Audio Block
The audio circuit is mounted on the IO board, and included the internal MIC terminal (MIC901) and the external MIC terminal
(CN504) as the audio input and included the SP terminal (CN505) as the audio output, and supports one channel respectively
for audio input of the microphone and audio output from the camera. The internal MIC (MIC901) audio signal is mounted on the
LED board, and is connected with the PCM codec (IC531) via CN901
→
CN505.
When the audio is output from the camera, the audio output become possible that external speaker is connected with the SP
terminal.
ALC Amplifier (IC532/533)
Power Supply: 3.3 V
Amplifier for Auto Level Control
PCM Codec (IC531)
Power Supply Voltage: 3.3 V
Clock Frequency: Contains a built-in PLL function and generates a clock from the BCLK (256 KHz).
That contains an amplifier, LPF, gain adjustment, AD/DA converter, host I/F, PCM serial I/F and speaker output function.
Flow of audio Signal
[Microphone audio]
1. Ordinarily microphone audio is selected internal MIC audio, the audio signal, after being amplified by the amplifier in the PCM
codec (IC531) and by the ALC (IC532), is applied to the PCM codec (IC531) again. When the input audio signal level exceeds
a certain level, the ALC (IC532) changes the gain to keep the output signal level constant and to constrain the distortion in the
voice.
On the other hand, when the external microphone connect with CN504, the audio signal, after being amplified by the amplifier
in the PCM codec (IC531) and by the ALC (IC533), is applied to the PCM codec (IC531) again. And the MIC changeover
detection signal send the CPU, is switched the audio signal from the internal MIC to the external MIC in CPU codec (IC531).
2. In the PCM Codec (IC531), by a register setting from the host, amplification, AD conversion and gain adjustment are per-
formed.
The sampling frequency of the A/D conversion is 8kHz and it is converted to the PCM in the format of 8bit and
µ
law. Then,
64kbps data are output to the IC101 on the Main board through the Serial I/F.
The data transfer of the Serial I/F is BCLK (256 kHz).
3. The data compression of 32 kbps is performed in the ADPCM Block inside of the IC101 and the data transferred as audio
data.
[Speaker audio]
1. The ADPCM audio data are sent from the PC and, after data decompression in the ADPCM block of the CPU (IC101), the
data are transferred as the audio data of 64 kbps to the PCM Codec (IC601) through the Serial I/F.
Summary of Contents for BB-HCM547A
Page 8: ...8 BB HCM547A 4 Technical Descriptions 4 1 CPU Peripheral Block ...
Page 21: ...21 BB HCM547A 6 Installation Instructions 6 1 Installation Guide ...
Page 22: ...22 BB HCM547A ...
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Page 24: ...24 BB HCM547A ...
Page 25: ...25 BB HCM547A ...
Page 26: ...26 BB HCM547A 6 2 Setup Guide ...
Page 27: ...27 BB HCM547A ...
Page 28: ...28 BB HCM547A 7 Troubleshooting Guide 7 1 Basic Operation ...
Page 29: ...29 BB HCM547A 7 2 Other Function Check ...
Page 30: ...30 BB HCM547A 7 3 Power Supply Block Check ...
Page 31: ...31 BB HCM547A 7 4 CPU Peripheral Block Check ...
Page 32: ...32 BB HCM547A 7 5 LVDS Block Check ...
Page 33: ...33 BB HCM547A 7 6 Image Block Check ...
Page 34: ...34 BB HCM547A 7 7 Audio Block Check ...
Page 35: ...35 BB HCM547A 7 8 LAN Block Check ...
Page 36: ...36 BB HCM547A 7 9 Motor Block Check ...
Page 37: ...37 BB HCM547A 7 10 Lens Block Check ...
Page 38: ...38 BB HCM547A ...
Page 39: ...39 BB HCM547A 7 11 I O Terminal Check ...
Page 40: ...40 BB HCM547A 7 12 SD Card Block Check ...
Page 41: ...41 BB HCM547A 7 13 RTC Circuit Check ...
Page 42: ...42 BB HCM547A 7 14 LED Circuit Check ...
Page 43: ...43 BB HCM547A 7 15 Diagnosis NG Check ...
Page 44: ...44 BB HCM547A 7 16 Version Upgrade Check ...
Page 50: ...50 BB HCM547A 8 1 2 How To Remove Tilt Board 1 Remove Dome Cover ...
Page 75: ...75 BB HCM547A F1 F2 H1 H2 H3 G E C1 C2 E1 E2 K I3 I2 I1 ...
Page 76: ...76 BB HCM547A N1 L3 L2 L1 K5 K4 M1 M2 K6 K2 K1 K3 N2 O S Q R P ...
Page 77: ...77 BB HCM547A U T V3 V2 V1 W3 W1 W2 W4 X1 X2 X4 X3 ...
Page 78: ...78 BB HCM547A Z5 Z6 Y1 Y2 Y3 Z4 Z1 ZA1 ZA3 ZA2 Z3 Z2 ...
Page 88: ...88 BB HCM547A ...
Page 90: ...90 BB HCM547A 13 2 Accessories and Packing Materials ...
Page 99: ...99 BB HCM547A A BBHCM547A ...