KL34018 IK Semicon Co., Ltd, KL34018 Datasheet - Page 3

• Manufacturer Part Number: KL34018
• Description: Linear Integrated Circuit Voice Switched Speaker Phone Circuit
• Manufacturer: IK Semicon Co., Ltd

PIN CONFIGURATIONS
PIN NAME
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
RR
RTX
TXI
TXO
TLI
TLO
RLI
RLO
MCI
MCO
CP1
CP2
XDI
SKG
SKO
V+
AGC
SKI
VCC
VB
GND
XDC
VLC
ACF
RXO
RXI
RRX
CS
A resistor to ground provides a reference current for the transmit and receive attenuators
A resistor to ground determines the nominal gain of the transmit attenuator ,the transmit channe
inversely proportional to RTX resistance.
Input to the transmit attenuator. Input resistance is nominally 5.0k ohms.
Output of the transmit attenuator. The TXO output signal drivers the input of transmit level detce
as the external circuit which drivers the telephone line.
Input of the transmit level detector. An external resistor ac coupled to The TLI pin sets the detec
Decreasing this resistor increases the sensitivity to transmit channel signals.
Output of the transmit level detector. The external resistor and capacitor set the time the compa
hold the system in the transmit mode after speech ceases.
Input of the receive level detector. An external resistor ac coupled to The RLI pin sets the detec
Decreasing this resistor increases the sensitivity to receive channel signals
Output of the receive level detector. The external resistor and capacitor set the time the compar
hold the system in the receive mode after speech ceases
Microphone amplifier input. Input impedance is nominally 10k ohms and the dc bias voltage is
approximately equal to VB
Microphone amplifier output. The MIC amp gain is internally set at 34dB(50V/V)
A parallel resistor and capacitor connected between this pin and VCC holds a voltage correspon
to the background noise level. The transmit detector compares the CP1 voltage with the speech s
CP2.
A capacitor at this pin peak detects the speech signals for comparison with the background noise
at CP1.
Input to the transmit detector system. The microphone amplifier output is ac coupled to the XD
High current ground pin for the speaker amplifier output stage. The SKG voltage should be wit
10mV of the ground voltage at pin 22
Speaker amplifier output. The SKO pin will source and sink up to 100mA when ac coupled to th
speaker. The speaker amplifier gain is internally set at 34dB(50V/V).
Input DC supply voltage. V+ can be powered from Tip and Ring if an ac decoupling inductor is
prevent loading ac line signals. The required V+ voltage is 6.0V to 11V(7.5V nominal ) at 7.0m
A capacitor from this pin to VB stabilizes the speaker amplifier gain control loop, and additional
controls the attack and decay time of this circuit. The gain control loop limits the speaker amplif
to prevent clipping at SKO. The internal resistance at AGC pin is nominally 110k ohms.
Digital chip select input. When at a logic "0" (<0.7V) the VCC regulator is enabled. When at a l
(>1.6V),the chip is in the standby mode drawing 0.5mA.An open
Impedance is nominally 140k ohms. The input voltage should not exceed 11V
Input to the speaker amplifier. Input impedance is nominally 20k ohms
A 5.4V regulated output which powers all circuits except the speaker amplifier output stage
An output voltage equal to approximately VCC/2 which series as an analog ground for the
speakerphone system. Up to 1.5mA of external load current may be sourced from VB. Output
impedance is 250 ohms. A filter capacitor is required
Ground pin for the IC(except the speaker amplifier)
Transmit detector output. A resistor and capacitor at his pin hold the system in the transmit mode
pauses between words or phrases. When the XDC pin voltage decays to ground, the attenuators
from the transmit mode to idle mode. The internal resistor at XDC is nominally 2.6k ohms(see
Volume control input>connecting this pin to the slider of a variable resistor provides receive mo
volume control. The VLC pin voltage should be less than or equal to VB
Attenuator control filter. A capacitor connected to this pin reduces noise transient as the attenua
control switches level of attenuation
Output of the receive attenuator. Normally this pin is ac coupled to the input of the speaker amp
Input of the receive attenuator. Input impedance is nominally is 5.0k ohms
A resistor to ground determines the nominal gain of the receive attenuator. The receive channel
directly proportional to the RRX resistance
through an external resistor
DESCRIPTION
CS
pin is a logic "0". Input
Rev. 00
KL34018