STLC3055N

Pin description

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17

RS

Protection resistors image (the image resistor is connected from this node to ZAC).

18

ZB

Balance network for 2 to 4 wire conversion (the balance impedance ZB is connected

from this node to AGND. ZA impedance is connected from this node to ZAC1).

19

CAC

AC feedback input, AC/DC split capacitor (CAC).

20

TX

4 wire output port (TX output). The signal is referred to AGND. If connected to single

supply CODEC input it must be DC decoupled with proper capacitor.

21

VF

Feedback input for DC/DC converter controller.

22

CLK

Power switch controller clock (typ. 125 kHz). This pin can also be connected to CVCC

or AGND. When the CLK pin is connected to CVCC an auto-oscillation is internally

generated and it is used instead of the external clock. When the CLK pin is connected

to AGND, the GATE output is disabled.

23

GATE

Driver for external Power MOS transistor (P-channel).

24

RSENSE

Voltage input for current sensing. RSENSE should be connected close to this pin and

VPOS pin. The PCB layout should minimize the extra resistance introduced by the

copper tracks.

25

VPOS

Positive supply

26

CVCC

Internal positive voltage supply filter.

27

AGND

Analog ground, must be shorted with BGND.

28

RLIM

Constant current feed programming pin (via RLIM). RLIM should be connected close to

this pin and AGND pin to avoid noise injection.

29

IREF

Internal bias current setting pin. RREF should be connected close to this pin and

AGND pin to avoid noise injection.

30

RTH

Off-hook threshold programming pin (via RTH). RTH should be connected close to this

pin and AGND pin to avoid noise injection.

31

RD

DC feedback and ring trip input. RD should be connected close to this pin and AGND

pin to avoid noise injection.

32

ILTF

Transversal line current image output.

33

CSVR

Battery supply filter capacitor.

34

BGND

Battery ground, must be shorted with AGND.

35

VBAT

Regulated battery voltage self generated by the device via DC/DC converter. Must be

shorted to VBAT1.

37

RING

2 wire port; RING wire (Ib is the current sunk into this pin).

41

TIP

2 wire port; TIP wire (Ia is the current sourced from this pin).

43

CREV

Reverse polarity transition time control. One proper capacitor connected between this

pin and AGND is setting the reverse polarity transition time. This is the same transition

time used to shape the "trapezoidal ringing" during ringing injection.

44

VBAT1

Frame connection. Must be shorted to VBAT.

Table 2.

Pin description (continued)

N°

Pin

Function