STLC3065Q STMicroelectronics, STLC3065Q Datasheet - Page 8

• 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
in series (see fig.2), where Rp is the external pro-
tection resistance.
It should be noted that in case of both ports in HI-
Z mode and both of them in off-hook condition the
power dissipated inside the chip could drive the
device in thermal protection. This can be pre-
vented via a proper software control that should
avoid to keep as a steady condition both lines in
off-hook and HI-Z mode. Typical operation is to
set the SLIC core in active mode as soon as off-
hook is detected.
Figure 2. DC characteristic in HI-Z mode.
AC CHARACTERISTICS
The AC impedance shown at the 2W ports
(TIP1/RING1 and TIP2/RING2) is the same as
the DC one. Depending on the P1, P2 bits the
TIP1/RING1 and TIP2/RING2 AC impedance will
be 2x(1500 + Rp) or high impedance.
Active
DC CHARACTERISTICS & SUPERVISION
When this mode is selected it is because one
connected telephone goes off-hook and the
STLC3065 is providing both DC feeding and AC
transmission.
The SLIC core is in ACTIVE mode and normally
only one of the two port should be connected to it:
8/27
D0
X
X
X
X
2x(R1+Rp)
Vbat
D1
1
1
1
1
D2
IL
X
X
X
X
P1
0
1
0
1
Slope: 2x(R1+Rp)
P2
0
1
1
0
line 1+2
disable disable disable
off/hk
off/hk
line 2
off/hk
line 1
DET
(R1=1500ohm)
Vbat (-50V)
disable disable
disable disable
disable disable
DET1
DET2
VL
P1,P2 = (1,0) or (0,1). (see Fig.1 and Table 2).
The unselected port is anyway DC biased being
TIP wire connected to BGND via a 1600W resis-
tor and the RING wire connected to a 300mA
(min.) current source connected to Vbat.
It should be noted that since Vbat is self gener-
ated by the STLC3065 and it is tracking the line
voltage depending on the loop resistance con-
nected to the selected port its voltage can range
typically from -12V to -50V. The unselected port
status (on/off hook) cannot be detected. For spe-
cial configurations it is also possible to set AC-
TIVE mode with both port selected (P1,P2=1,1) or
both unselected (P1,P2=0,0).
Considering now the selected port, this is con-
nected to the SLIC core. The STLC3065 feeds
the line with a constant current fixed by RLIM
(20mA to 40mA range). The on-hook voltage is
typically 40V allowing on-hook transmission; the
self generated Vbat is -52V typ.
If the loop resistance is very high and the line
current cannot reach the programmed constant
current feed value, the STLC3065 behaves like a
40V voltage source with a series impedance
equal to the protection resistors 2xRp(typ. 2x41 )
plus the line series switches (Sw1 or Sw2) on re-
sistance 2xRsw (typ. 2x9 ).
Fig.3 shows the typical DC characteristic in AC-
TIVE mode.
Figure 3. DC characteristic in ACTIVE mode
The line status (on/off hook) is monitored by the
SLIC core Supervision circuit. The off-hook
threshold can be programmed via the external
resistor RTH in the range from 5mA to 9mA.
When the line goes in off-hook condition the built
in DC/DC converter controller set properly the
Vbat supply in order to keep the loop current fixed
to the programmed value.
Independently on the programmed constant cur-
rent value, the TIP and RING buffers have a cur-
rent source capability limited to 70mA typ.
40mA)
(20 to
Ilim
IL
10V
2Rp+2Rsw
(100ohm typ.)
Vbat (-50V)
VL