13/26

STLC3075

Table 13. External Components @Gain Set = 1

(1) In case Zs=Zl, ZA and ZB can be replaced by two resistors of same value: RA=RB=|Zs|.

(2) In this case CTTX is just operating as a DC decoupling capacitor (fp=100Hz).

(3) Defining ZTTX as the impedance of RTTX in series with CTTX, RTTX and CTTX can also be calculated from the following formula:

ZTTX=50*(Zlttx+2Rp).

(4) CVpos should be defined depending on the power supply current capability and maximum allowable ripple.

(5) For low ripple application use 2x47

µ F in parallel.

(6) Can be saved if proper PCB layout avoid noise coupling on RD pin (high impedance input).

(7) RF1 sets the self generated battery voltage in RING and ACTIVE(Il=0) mode as follows:

VBATR should be defined considering the ring peak level required (Vringpeak=VBATR-6V typ.).

The above relation is valid provided that the Vpos power supply current capability and the RSENSE programming allow to source all the

current requested by the particular ringer load configuration.

(8) For high efficiency in HI-Z mode coil resistance @125kHz must be < 3

Ω

Name

Function

Formula

Typ. Value

CTTX (3) Pulse metering cancellation

capacitor

CTTX = 1/{50

⋅2π⋅fttx[-lm(Zlttx)]}

100nF 10% 10V (2)

@ Zlttx = 200

Ω real

RLV

Pulse metering level resistor

α = (|Zlttx + 2Rp|/|Zlttx|)

16.2k

CS

Pulse metering shaping capacitor CS =

τ/(2⋅RLV)

100nF 10% 10V

@

τ = 3.2ms, RLV = 16.2kΩ

CFL

Pulse metering filter capacitor

CFL = 2/(2

π⋅fttx⋅RLV)

1.5nF 10% 10V

@fttx = 12kHz RLV = 16.2k

Ω

Name

Function

Formula

Typ. Value

RS

Protection resistance image

RS = 25

⋅ (2Rp)

2.55k

Ω @ Rp = 50Ω

ZAC

Two wire AC impedance

ZAC = 25

⋅ (Zs - 2Rp)

12.5k

Ω 1% @ Zs = 600Ω

ZA (1)

SLIC impedance balancing

network

ZA = 25

⋅ Zs

15k

Ω 1% @ Zs = 600Ω

ZB (1)

Line impedance balancing

network

ZB = 25

⋅ Zl

15k

Ω 1% @ ZI = 600Ω

CCOMP

AC feedback loop compensation

fo = 250kHz

CCOMP = 2/(2

π⋅fo⋅100⋅(RP))

220pF 10% 10VL @ Rp = 50

Ω

CH

Trans-Hybrid Loss frequency

compensation

CH = CCOMP

220pF 10% 10V

RTTX (3)

Pulse metering cancellation

resistor

RTTX = 25Re (Zlttx+2Rp)

7.5k

Ω @Zlttx = 200Ω real

CTTX (3) Pulse metering cancellation

capacitor

CTTX = 1/25

⋅2π⋅fttx⋅[-lm(Zlttx)]

100nF 10% 10V (2)

@ Zlttx = 200

Ω real

RLV

Pulse metering level resistor

α = (|Zlttx + 2Rp|/|Zlttx|)

16.2k

CS

Pulse metering shaping capacitor CS =

τ/(2⋅RLV)

100nF 10% 10V

@

τ = 3.2ms, RLV = 16.2kΩ

CFL

Pulse metering filter capacitor

CFL = 2/(2

π⋅fttx⋅RLV)

1.5nF 10% 10V

@fttx = 12kHz RLV = 16.2k

Ω

267k

Ω

280k

Ω

294k

Ω

300k

Ω

-46V

-48V

-49V

-50V

-62V

-65V

-68V

-70V

Table 12. External Components @Gain Set = 0 (continued)