TEA7540 ST Microelectronics, Inc., TEA7540 Datasheet - Page 7

• Manufacturer Part Number: TEA7540
• Description: Handsfree Controller
• Manufacturer: ST Microelectronics, Inc.

ELECTRICAL CHARACTERISTICS (continued)
Figure 1: Basic Configuration
ATR-IDLE Mode: Noise RX, TX Comp.
ATR-active Mode: Active
ATRVOL
PEAK DETECTOR
NOISE MEMORIZAT ION
ATTENUATOR
ATTENUATION CONTROL SECTION
MICROPHONE PREAMPLIFIER
ATR-
V
V
R
R
Rina
I
I
G
G
TIME
TIMR
I
V1
TIME
TIMR
inp d
cr2
amp
2off
mic
Input impedance
Rise time current
Max voltage drop on PIN 19
Input impedance
Attenuation= 20lg(Voutr/Vatte)
Mode: Inactive RX, TX
Comp. Max Gain
Max Gain
Tx Mode Att.Voltage
TX Mode Att.Current
RX Mode Att.Voltage
RX Mode Att.Current
Volume Control
Imput impedance
V
Compressor Gain
Monitoring Mode
G2 = V
mic
= Voute-Vamp in
recout
/V
inr
PIN17
PIN25
Rpin24 = 11K
Rpin24 = 15K
Rpin24 = 11K
Rpin24 = 11K
PIN21
V
Rext between PINs 2 - 28
Rext = open
Rext = 40K
cs
open
Figure 2: Test Configuration
V
pin 7 is forced to transmit mode
pin 11 is forced to max gain
Input signal on pin 13 VINE = 1.5mVpp
output voltage VMICOUT measured on pin 12
+
= 3V
G1max = 20log (VMICOUT / VINE)
-325
190
7.5
7.5
16
33
40
40
29
35
19
0
-250
36.5
250
1.5
10
20
36
10
46
58
23
50
50
32
50
20
16
14.5
14.5
-190
325
24
45
70
70
35
70
21
3
K
mV
K
mV
mV
K
dB
dB
dB
dB
dB
dB
dB
dB
A
A
A
TEA7540
10
11
12
12
13
13
14
1
7
8
1
9
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