SI3019-F-FM View Datasheet(PDF) - Silicon Laboratories

Part Name

Description

Manufacturer

SI3019-F-FM

PROGRAMMABLE VOICE DAA SOLUTIONS

Silicon Laboratories 

Si3050 + Si3011/18/19

5.27. Gain Control

The Si3050 supports multiple levels of gain and

attenuation for the transmit and receive paths.

The TXG2 and RXG2 bits (Registers 38–39) enable

gain or attenuation in 1 dB increments for the transmit

and receive paths (up to 12 dB gain and 15 dB

attenuation). The TGA2 and RGA2 bits select either

gain or attenuation. The TXG3 and RXG3 bits

(Registers 40–41) enable gain or attenuation in 0.1 dB

increments up to 1.5 dB for the transmit and receive

paths. The TGA3 and RGA3 bits select either gain or

attenuation. The transmit and receive paths can be

individually muted with the TXM and RXM bits

(Register 15). The signal flow through the Si3050 and

the Si3011/18/19 is shown in Figures 27–28.

DAC

ACT

TX

To

Si3050

Link

Analog

Hybrid

CO

ADC

0.6 Hz

HPF

Figure 27. Si3011/18/19 Signal Flow Diagram

DRX

TXG2

1 dB

Gain

Steps

TXG3

TXA3

0.1 dB

Gain/ATT

Steps

IIRE

Digital

Filter

1 dB

Attenuation

Steps

DTX

RXA2

IIRE

Digital

Filter

0.1 dB

Gain/ATT

Steps

RXG3

RXA3

1 dB

Gain

Steps

RXG2

TXA2

1 dB

Attenuation

Steps

Digital

Hybrid

Selectable

200 Hz

HPF

Link

To

Si3011/18/19

Figure 28. Si3050 Signal Flow Diagram

5.28. Transhybrid Balance

The Si3050 contains an on-chip analog hybrid that

performs the 2- to 4-wire conversion and near-end echo

cancellation. This hybrid circuit is adjusted for each ac

termination setting selected to achieve a minimum

transhybrid balance of 20 dB when the line impedance

matches the impedance set by ACIM.

The Si3050 also offers a digital hybrid stage for

additional near-end echo cancellation. For each ac

termination setting, the eight programmable hybrid

registers (Registers 45–52) can be programmed with

coefficients to increase cancellation of real-world line

impedances. This digital filter can produce 10 dB or

greater of near-end echo cancellation in addition to the

trans-hybrid loss from the analog hybrid circuitry.

Coefficients are 2s complement, where unity is

represented as binary 0100 0000b, the maximum value

as binary 0111 1111b, and the minimum value as binary

1000 000b. See AN84 for a more detailed description of

the digital hybrid and how to use it.

38

Rev. 1.5

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