STLC3075_09 Datasheet, PDF (7/36 Pages) STMicroelectronics – Integrated POTS interface for home access gateway and WLL

STLC3075
Pin description
Table 2.
N°
16
17
18
19
20
21
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
41
43
44
Pin description (continued)
Pin
Function
RS
ZB
CAC
TX
CZ
VF
CLK
GATE
R_SENSE
V_POS
CVCC
AGND
RLIM
IREF
RTH
RD
ILTF
CSVR
BGND
VBAT
RING
TIP
CREV
VBAT1
Protection resistors image (the image resistor is connected from this node to ZAC)
Balance network for 2 to 4 wire conversion (the balance impedance ZB is connected
from this node to AGND. ZA impedance is connected from this node to ZAC1).
AC feedback input, AC/DC split capacitor (CAC)
4 wire output port (TX output). The signal is referred to AGND. If connected to single
supply CODEC input it must be DC decoupled with proper capacitor.
Flyback compensation
Feedback input for DC/DC converter controller
Power switch controller clock (typ. 125 kHz). This pin can also be connected to CVCC
or AGND. When the CLK pin is connected to CVCC an internal auto-oscillation is
internally generated and it is used instead of the external clock. When the CLK pin is
connected to AGND, the GATE output is disabled.
Driver for external power MOS transistor (P-channel in buckboost configuration, N-
channel in flyback configuration).
Voltage input for current sensing. R_SENSE resistor should be connected close to this
pin and V_POS pin (Buckboost) or GND (Flyback). The PCB layout should minimize the
extra resistance introduced by the copper tracks.
Positive supply input
Internal positive voltage supply filter
Analog ground. Must be shorted with BGND.
Constant current feed programming pin (via RLIM). RLIM should be connected close
to this pin and AGND pin to avoid noise injection.
Internal bias current setting pin. RREF should be connected close to this pin and
AGND pin to avoid noise injection.
Off-hook threshold programming pin (via RTH). RTH should be connected close to this
pin and AGND pin to avoid noise injection.
DC feedback and ring trip input. RD should be connected close to this pin and AGND
pin to avoid noise injection.
Transversal line current image output
Battery supply filter capacitor
Battery ground, must be shorted with AGND
Regulated battery voltage self generated by the device via DC/DC converter. Must be
shorted to VBAT1.
2 wire ports; RING wire (Ib is the current sunk into this pin)
2 wire ports; TIP wire (Ia is the current sourced from this pin)
Reverse polarity transition time control. A proper capacitor connected between this pin
and AGND is setting the reverse polarity transition time. This is the same transition
time used to shape the ’trapezoidal ringing’ during ringing injection.
Frame connection. Must be shorted to VBAT
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