UBA1707 NXP Semiconductors, UBA1707 Datasheet - Page 10

• Manufacturer Part Number: UBA1707
• Description: Cordless Telephone, Answering Machine Line Interface
• Manufacturer: NXP Semiconductors

Philips Semiconductors
The UBA1707 offers the possibility to choose two kinds of
regulations for the DC characteristic between the line
terminals LN+ and LN (see Fig.7):
The regulation mode is selected by the bit CRC via the
serial interface.
The DC mask regulation is realised by adjusting the DC
voltage V
LN as a function of the line current.
Voltage regulation mode
In voltage regulation mode (bit CRC at logic 0),
V
constant current I
1999 Feb 17
handbook, halfpage
CE
V line
Voltage regulation mode
Current regulation mode.
Cordless telephone, answering machine
line interface
(1) Low voltage area.
(2) Small slope (determined by R
(3) Small slope (dashed line; determined by R
(4) Current limitation.
Fig.7
(TN
regulation mode.
High slope (full line; determined by R
current regulation mode.
SW
CE
(1)
) voltage is fixed by means of a 200 nA DC
General form of the DC mask as a function
of regulation mode.
(TN
I low
SW
LVIV
) between pin GND and line terminal
flowing through R
(2)
I knee
SLPE
).
SLPE
, R
(3)
SLPE
LVI
LVI
) in voltage
.
and R
I prot
RGL
MGK710
) in
(4)
I line
10
Therefore V
application (see Fig.18).
The slope V
R
Current regulation mode
In current regulation mode (bit CRC at logic 1), when the
line current is lower than I
Z
DC constant current I
line current is higher than 35 mA, an additional current
(proportional to the line current) flows through R
result, TN
the line current. V
Where:
The slope V
determined by the ratio of resistors connected at
pins SLPE, LVI and RGL, and can be calculated as
follows:
typical application (see Fig.18).
Current limitation
Whatever the selected mode is, the line current is limited
to approximately 145 mA. This current is sensed on SLPE,
for this purpose the external zener diode must be
connected between pins LN and SLPE. The speech
function no longer operates in this condition.
E
The electronic hook switch input (EHI) controls the state of
TP
LOW, TP
pulled up to supply voltage (V
transistors are also turned off by means of a pull-down
resistor (R
HIGH, TP
amplifier at pin LCC and the regulation mode selected is
operating. An internal 165 k pull-up resistor is connected
between pins LCC and V
V
SET
LECTRONIC HOOK SWITCH CONTROL
REGV
CE
I
R
line
DARL
RGL
= 619 ), V
TN
= line current
= resistor connected at pin RGL.
transistor. When the voltage applied at pin EHI is
R
SW
R
DARL
SW
DARL
REGC
PLD
SLPE.
CE
works as a DC voltage source increasing with
line
line
). When the voltage applied at pin EHI is
transistor is turned off. Voltage at pin LCC is
(TN
transistor is driven by the operational
R
/ I
/ I
CE
LVI
R
CE
SW
line
line
SLPE
(TN
(TN
LVIV
)
of the V
of the V
R
--------------- -
SW
R
+
SW
R
SLPE
CC
RGL
flowing through R
knee
R
LVI
) is fixed by means of a 200 nA
) can be calculated as follows:
.
LVI
CC
line
line
= 35 mA (with
I
LVIV
). TN
, I
, I
R
--------------- -
I
R
line
line
line
SLPE
RGL
(
= 200 mV in typical
PIN
Product specification
–
SW
characteristic is
characteristic is
I
knee
=
EHI)
and TN
UBA1707
1400
LVI
+
. When the
I
LVIV
LVI
ON-HOOK
in
. As a