L6726

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

2 of 13

www.unisonic.com.tw

QW-R108-015, C

PIN CONFIGURATION

PIN DESCRIPTIONS

Pin

No.

Pin

Name

Description

1

+L

Output of the DC-regulator and transmit amplifier. This pin is connected to the line through a polarity

guard and diode bridge.

2

TO

Output of the transmit amplifier. This pin is connected through a resistor of 47 to 100Ω to -L, which

sets the DC-resistance of the circuit. The output has a low AC output impedance and the signal is

used to drive a side tone balancing network.

3

TI

Input of transmit amplifier. Input impedance 17kΩ±20%

4

+C

The positive power supply terminal for most of the circuitry inside the UTC L6726 (about 1mA current

consumption).The +C-PIN shall be connected to a decoupling capacitor of 47μF to 150μF

5

Mute

When low, speech circuit is muted and the DTMF input is enabled. Maximum voltage (at mute) is

0.3V,current sink requirement of external driver is 50μA

6

GR

Control input for the gain regulation circuitry.

7

DCS

The sense input to the DC-supply.

8

DCO The output from the DC-supply.

9

DCC The control output from the DC-supply

10

DI

The input for the DTMF-signal. Input impedance is 25kΩ±20%

11

MO

Output of the microphone amplifier or DTMF-amplifier

12

MI 1

Input to the microphone amplifier. Input impedance 1.7kΩ±20%

13

MI 2

14

-L

The negative power terminal, connected to the line though a polarity guard diode bridge

15

RI

Input of receiver amplifier. Input impedance is approximately 38kΩ±20%

16

DR

The control input for the receiver amplifier driving capability.

17

RE 1

Receiver amplifier outputs. Output impedance is approximately 3Ω.

18

RE 2