U4082B Datasheet, PDF (3/30 Pages) ATMEL Corporation – Low-voltage Voice-switched IC for Hands-free Operation

2. Pin Configuration
Figure 2-1. Pinning SO28
FO
1
FI
2
CD
3
VS
4
HTO+ ⁵
HTO- ⁶
HTI
7
TO
8
TI
9
MICO ¹⁰
MIC ¹¹
MUTE ¹²
VCI
13
CT
14
28 GND
27 CPR
26 _RLI1
25 _RLO1
24 _TLO1
23 _TLI1
22 RECO
21 RI
20 _RLI2
19 _RLO2
18 _TLO2
17 _TLI2
16 _CPT
15 _VB
U4082B
Table 2-1.
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Pin Description
Symbol Function
FO
Filter output. Output impedance is less than 50Ω
FI
Filter input. Input impedance is greater than 1 MΩ
CD
Chip disable. A logic low (< 0.8V) sets normal operation. A logic high (> 2V) disables the IC to conserve
power. Input impedance is nominally 90 kΩ
VS
Supply voltage 2.8V to 6.5V, approximately 5 mA. AGC circuit reduces the receive attenuator gain at
25 dB, receive mode at 2.8V
HTO+
Output of the second hybrid amplifier (Hybrid output). Gain is internally set at –1 to provide a differential
output, (in conjunction with HTO–) to the hybrid transformer
HTO– Output of the first hybrid amplifier. Hybrid output. Gain is set by external resistors
HTI
Input and summing node for the first hybrid amplifier. DC level is approximately V_B
TO
Transmit attenuator output. DC level is approximately V_B
TI
Transmit attenuator input. Maximum signal level is 350 mVrms. Input impedance is approximately 10 kΩ
MICO Microphone amplifier output. Gain is set by external resistors
MIC
MUTE
Microphone amplifier input. Bias voltage is approximately V_B
Mute input. A logic low (< 0.8V) sets normal operation. A logic high (> 2V) mutes the microphone
amplifier without affecting the rest of the circuit. Input impedance is nominally 90 kΩ
VCI
Volume control input. When VCI = V_B, the receive attenuator is at maximum gain when in receive mode.
When VCI = 0.3 V_B, the receive gain is down 35 dB. It does not affect the transmit mode
CT
Response time. An RC at this pin sets the response time for the circuit to switch modes
3
4743D–CORD–03/06