U4082B-DEV-BOARD Atmel, U4082B-DEV-BOARD Datasheet - Page 8

• Manufacturer Part Number: U4082B-DEV-BOARD
• Description: WiFi / 802.11 Modules & Development Tools Voice Switched Circuit
• Manufacturer: Atmel

3.8
3.9
8
Attenuator Control Block
Term Definitions
U4082B
The attenuator control block has seven inputs:
The single output of the control block controls the two attenuators. The effect of C1 to C4 is as
follows:
Table 3-1.
Note:
• The output of the comparator operated by RLO2 and TLO2 (microphone/speaker side) –
• The output of the comparator operated by RLO1 and TLO1 (Tip/Ring side) – designated C2
• The output of the transmit background noise monitor – designated C3
• The output of the receive background noise monitor – designated C4
• The volume control
• The dial tone detector
• The AGC circuit
• “Transmit” means the transmit attenuator is fully on (+6.0 dB), and the receive attenuator is at
• “Receive” means both attenuators are controlled by the volume control. At maximum volume,
• “Fast Idle” means both transmit and receive speech are present in approximately equal
• “Slow Idle” means speech has ceased in both transmit and receive paths. The attenuators
• Switching to full transmit or receive mode from any other mode is at the fast rate (
designated C1
maximum attenuation (–46 dB).
the receive attenuator is fully on (+6.0 dB), and the transmit attenuator is at maximum
attenuation (–46 dB).
levels. The attenuators are quickly switched (30 ms) to idle mode until one speech level
dominates the other.
are then slowly switched (1s) to idle mode.
C1
R
R
R
R
T
T
T
T
X = Do not care; Y = C3 and C4 are not both 0.
Mode Selection Table
C2
R
R
R
R
T
T
T
T
Inputs
C3
Y
Y
X
0
X
1
0
0
C4
X
Y
Y
X
1
0
0
0
Output Mode
Slow Idle
Slow Idle
Slow Idle
Slow Idle
Transmit
Fast Idle
Fast Idle
Receive
4743D–CORD–03/06
30 ms).