STLC3065Q STMicroelectronics, STLC3065Q Datasheet - Page 10

• Manufacturer Part Number: STLC3065Q
• Manufacturer: STMicroelectronics

Specifications of STLC3065Q

• Number Of Channels: 1
• On-hook Transmission: Yes
• Polarity Reversal: Yes
• On-chip Ring Relay Driver: Yes
• Operating Temp Range: -40C to 85C
• Package Type: TQFP
• Operating Temperature Classification: Industrial
• Pin Count: 44
• Mounting: Surface Mount
• Operating Supply Voltage (min): 5.5V
• Lead Free Status / RoHS Status: Not Compliant

STLC3065
Figure 5. Metering pulse generation circuit.
As already mentioned the metering pulse echo
cancellation is obtained by means of two external
components (RTTX and CTTX) that should match
the line impedance at the TTX frequency. This
simple network has a double effect:
Ringing
When this mode is selected STLC3065 self gen-
erate an higher negative battery (-70V typ.) in or-
der to allow a balanced ringing signal of typically
62Vpeak.
The SLIC core is set in ring mode via the control
inputs D0 and D1 set respectively to 0 and 1.
In this condition both the DC and AC feedback
loop are disabled and the SLIC core line drivers
operate as voltage buffers.
The ring waveform is obtained toggling the D2 con-
trol bit at the desired ring frequency. This bit in fact
controls the line polarity (0=direct; 1=reverse).
As in the ACTIVE mode the line voltage transition
is performed with a ramp transition, obtaining in
10/27
D0
1
1
1
TIP/RING pins at the TTX frequency.
ferred from the line to the TX output.
Synthesise a low output impedance at the
Cut the eventual TTX echo that will be trans-
D1
0
0
0
@fr
@fr
@fr
0/1
0/1
0/1
D2
CKTTX
D0
Square wave pulse metering
P1
1
0
1
GENERATOR
SHAPING
BURST
P2
1
1
0
line 1+2
RTrip
RTrip
line 2
RTrip
line 1
DET
CS
CTTX2
CTTX1
disable disable
disable disable
disable disable
DET1
RLV
RLV
SQTTX
DET2
Low Pass Filter
Figure 6. TIP/RING typical ringing waveform
this way a trapezoidal balanced ring waveform
(see fig.6).
The shaping is defined by the CREV external
capacitor.
Selecting the proper capacitor value it is possible
to get different crest fattor values. The following
table shows the crest factor values obtained with
a 20Hz and 25Hz ring frequency and with 1REN.
This value are valid either with European or USA
specification:
(*)Distorsion already less than 10%.
CREV
CFL
R1
22nF
27nF
33nF
GND
VBAT
TIP
Required external components vs. filter order.
RING
Order CFL
1
2
3
dV/dT set
by CREV
R2
FTTX
X
X
2.5V typ.
2.5V typ.
C2
C1
R1
-
+
FACTOR
X
X
OP1
CREST
@20Hz
Sinusoidal wave
pulse metering
1.25
1.33
1.2
C!
X
X
RTTX
R2
X
X
Not significant (*)
FACTOR
CREST
@25Hz
C2
X
X
1.26
1.32
65V
typ.
THD
13%
6%
3%