STLC5048TR STMicroelectronics, STLC5048TR Datasheet - Page 15

• Manufacturer Part Number: STLC5048TR
• Description: IC CODEC/FILTER PROGR 4CH 64TQFP
• Manufacturer: STMicroelectronics
• Type: PCM Codec/Filterr

Specifications of STLC5048TR

• Data Interface: PCM Audio Interface
• Resolution (bits): 16 b
• Number Of Adcs / Dacs: 4 / 4
• Sigma Delta: Yes
• Voltage - Supply, Analog: 3.3 V ~ 5 V
• Voltage - Supply, Digital: 3.3 V ~ 5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 64-TQFP, 64-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

STLC5048
4.3
4.4
4.5
4.6
Ringing state
This state can be used during the ringing phase in order to transmit a low frequency ringing
signal (25-50 Hz). In order to obtain a 1 Vrms ringing signal at VFRO output a digital signal
DR equal to -0.78 dBm0 must be provided.
This state means B, Z, X, KD and KA blocks equal to open circuits and the R block
configured in order to obtain the maximum gain at the frequency of 25-50 Hz. During the
ringing state if the TX time slot is enabled the idle PCM code is forced to DX.
To switch to this state, a bit (FR0..3) in the COEFST register must be set for every channel.
The programmed values for the previous blocks become active only when the FR and FD
bits are reset.
If both FR and FD bits of a channel are set, the selected coefficient will be those of the
ringing state.
Impedance synthesis
The impedance synthesis is performed by fully digital filters (Z and KD) and by an analog
path (KA).
The Z, KD and KA filters report to the receive path the feedback signal coming from the
transmit path. The coefficients of the Z, KD and KA filters are programmed via the ZFC, KD
and AFE_CFF commands respectively.
Echo canceling
The trans-hybrid balance is performed by the digital programmable filter B.
The B filter reports to the transmit path the signal coming from the receive path. The
coefficient of the B filter are programmed via the BFC command.
Figure 4.
Transmit path
The transmit section input consist of the input amplifier, the A/D converter, the equalization
filter X, the gain block GX, the encoder and the channel filters (LPX and HPX).
The input amplifier is provided of a programmable gain with a typical input impedance of
1MΩ . The amplifier gain can be programmed with two different values (0 dB, +3.52dB) by
means of the TXG register.
VFXI
1MΩ
TXG
Transmit path
AGND
for TXG=0dB; GX=0dB (FF)
61mVms => 0dBm0
CONV.
ΣΔ
GXO
GX
Functional description
D00TL469
A/μ
DX
15/64