tea1065t NXP Semiconductors, tea1065t Datasheet - Page 5

• Manufacturer Part Number: tea1065t
• Description: Versatile Telephone Transmission Circuit With Dialler Interface
• Manufacturer: NXP Semiconductors

Philips Semiconductors
FUNCTIONAL DESCRIPTION
Supply: V
The circuit and its peripherals are usually supplied from the
telephone line. The circuit develops its own supply voltage
at V
and SLPE (pins 1 and 24). The internal supply requires a
decoupling capacitor between V
internal voltage regulator has to be decoupled by a
capacitor from REG (pin 22) to V
stabilizer is set by a 3.6 k resistor connected between
STAB (pin 9) and V
The TEA1065 can be set either in a DC voltage regulator
mode or in a DC current regulator mode. The DC mask can
be selected by connecting the appropriate external
components to the dedicated pins (VSI, REFI, DOC,
VBG).
When the DC current regulator mode is not required it can
be cancelled by connecting pin VSI to V
VBG and DOC are left open-circuit.
Voltage regulator mode
The voltage regulator mode is achieved when the line
current is less than the current I
With R13 = R14 = 30 k , the current I
(I
March 1994
handbook, full pagewidth
p
Versatile telephone transmission circuit with
dialler interface
= 0 mA).
CC
(pin 21) and regulates its voltage drop between LN
CC
, LN, SLPE, REG and STAB
EE
.
current
I knee
line
knee
CC
EE
0
and V
. The internal current
0
as illustrated in Fig.3.
regulator
voltage
mode
knee
Fig.3 Voltage and current regulator mode.
EE
EE
; pins REFI,
= 30 mA
(pin 16); the
regulator
current
mode
5
This line current value will be reached when the voltage on
pin VSI (almost equal to the voltage on pin SLPE) exceeds
the voltage on pin REFI (equal to the voltage on pin VBG
divided by the resistor tap R13, R14). For other values of
R13 and R14, the I
formula:
I
I
(typ. 1.14 mA). I
circuits connected between V
output current from pin VSI (typ. 2.5 A).
The DC slope of the V
determined by R9 (R9 = R9a
r
r
Current regulator mode
The current regulator mode is achieved when the line
current is greater than I
V
R16 = 1 M , R13 = R14 = 30 k . For other values of
these resistances, the slope value can be approximated by
the following formula:
R9
knee
CC
ds
ds
line
of the external line current control transistor (see Fig.4;
= V
is the current required by the circuit itself
/I
= I
line
{1
CC
GS
curve is approximately 1300
R16
/ I
I
(R15/R9)
D
P
at V
P
(1/R13
(VBG/R9)
is the current required by the peripheral
GS
knee
= V
voltage
line
set
current is given by the following
knee
MBA567
I
O
/I
DS
1/R14)}
(VSI)
line
. In this mode, the slope of the
).
{R14/(R14
CC
curve is, in this mode,
R9b) in series with the
and V
Product specification
EE
with R9 = 20 ,
. I
TEA1065
R13)}
O(VSI)
is the