STLC3055N Ver la hoja de datos (PDF) - STMicroelectronics

Número de pieza

componentes Descripción

fabricante

STLC3055N

WLL and ISDN-TA subscriber line interface circuit

STMicroelectronics 

STLC3055N

Application information

Table 11. External components @gain set = 0 (continued)

Name

Function

Formula

Typ. value

ZB(1)

Line impedance balancing

network

ZB = 50 ⋅ Zl

30 kΩ 1% @ Zl = 600 Ω

fo = 250 kHz

CCOMP AC feedback loop compensation

CCOMP = 1/(2π⋅fo⋅100⋅(RP))

120 pF 10% 10 V @ Rp = 50 Ω

CH

Trans-Hybrid Loss frequency

compensation

CH = CCOMP

120 pF 10% 10 V

RTTX(2)

Pulse metering cancellation

resistor

CTTX(2)

Pulse metering cancellation

capacitor

RLV Pulse metering level resistor

RTTX = 50Re (Zlttx+2Rp)

CTTX = 1/{50⋅2π⋅fttx[-

lm(Zlttx)]}

RLV = 63.3·103··α·VLOTTX

α = (|Zlttx + 2Rp|/|Zlttx|)

15 kΩ @Zlttx = 200 Ω real

100nF 10% 10V(3)

@ Zlttx = 200Ω real

16.2 kΩ @ VLOTTX = 170mVrms

CS

Pulse metering shaping

capacitor

CS = τ/(2⋅RLV)

100 nF 10% 10V

@ τ = 3.2 ms, RLV = 16.2 kΩ

CFL Pulse metering filter capacitor CFL = 2/(2π⋅fttx⋅RLV)

1.5 nF 10% 10 V

@fttx = 12 kHz RLV = 16.2 kΩ

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

2. 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).

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

Table 12. External components @gain set = 1

Name

Function

Formula

Typ. value

RS Protection resistance image

RS = 25 ⋅ (2Rp)

ZAC Two wire AC impedance

ZAC = 25 ⋅ (Zs - 2Rp)

ZA(1)

SLIC impedance balancing

network

ZA = 25 ⋅ Zs

ZB(1)

Line impedance balancing

network

ZB = 25 ⋅ Zl

fo = 250kHz

CCOMP AC feedback loop compensation

CCOMP = 2/(2π⋅fo⋅100⋅(RP))

CH

Trans-Hybrid Loss frequency

compensation

CH = CCOMP

RTTX(2)

Pulse metering cancellation

resistor

RTTX = 25Re (Zlttx+2Rp)

CTTX(2)

Pulse metering cancellation

capacitor

RLV Pulse metering level resistor

CTTX = 1/25⋅2π⋅fttx⋅[-lm(Zlttx)]

RLV = 31.7·103··α·VLOTTX

α = (|Zlttx + 2Rp|/|Zlttx|)

2.55 kΩ @ Rp = 50 Ω

12.5 kΩ 1% @ Zs = 600 Ω

15 kΩ 1% @ Zs = 600 Ω

15 kΩ 1% @ ZI = 600 Ω

220 pF 10% 10VL @ Rp = 50 Ω

220 pF 10% 10 V

7.5 kΩ @Zlttx = 200 Ω real

100 nF 10% 10 V(3)

@ Zlttx = 200 Ω real

16.2 kΩ @ VLOTTX = 340 mVrms

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