- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄368632 > TEA1118M (NXP SEMICONDUCTORS) Versatile cordless transmisssion circuit PDF資料下載
參數(shù)資料
| 型號： | TEA1118M |
| 廠商： | NXP SEMICONDUCTORS |
| 元件分類： | 無繩電話/電話 |
| 英文描述： | Versatile cordless transmisssion circuit |
| 中文描述： | TELECOM, CORDLESS, BASEBAND CIRCUIT, PDSO16 |
| 封裝： | SSOP-16 |
| 文件頁數(shù)： | 7/24頁 |
| 文件大?。?/td> | 188K |
| 代理商： | TEA1118M |
1997 Jul 14
7
Philips Semiconductors
Product specification
Versatile cordless transmisssion circuit
TEA1118; TEA1118A
FUNCTIONAL DESCRIPTION
All data given in this chapter are typical values, except
when otherwise specified.
Supplies (pins LN, SLPE, V
CC
and REG)
The supply for the TEA1118 and TEA1118A and their
peripherals is obtained from the telephone line.
The ICs generate a stabilized reference voltage (V
ref
)
between pins LN and SLPE. This reference voltage is
equal to 3.35 V, is temperature compensated and can be
adjusted by means of an external resistor (R
VA
). It can be
increased by connecting the R
VA
resistor between
pins REG and SLPE (see Fig.11), or decreased by
connecting the R
VA
resistor between pins REG and LN.
The voltage at pin REG is used by the internal regulator to
generate the stabilized reference voltage and is decoupled
by a capacitor (C
REG
) which is connected to V
EE
.
This capacitor, converted into an equivalent inductance
(see Section “Set impedance”), realizes the set impedance
conversion from its DC value (R
SLPE
) to its AC value
(R
CC
in the audio-frequency range). The voltage at pin
SLPE is proportional to the line current. Figure 7 illustrates
the supply configuration.
The ICs regulate the line voltage at pin LN, and it can be
calculated as follows:
V
LN
= V
ref
+ R
SLPE
×
I
SLPE
I
SLPE
= I
line
I
CC
I
P
I* = I
sh
where:
I
line
: line current
I
CC
: current consumption of the IC
I
P
: supply current for peripheral circuits
I*: current consumed between LN and V
EE
I
sh
: the excess line current shunted to SLPE (and V
EE
)
via LN.
The preferred value for R
SLPE
is 20
. Changing R
SLPE
will
affect more than the DC characteristics; it also influences
the transmit gain and the DTMF gain (TEA1118A only), the
gain control characteristics, the sidetone level and the
maximum output swing on the line.
The internal circuitry of the TEA1118 and TEA1118A is
supplied from pin V
CC
. This voltage supply is derived from
the line voltage by means of a resistor (R
CC
) and must be
decoupled by a capacitor C
VCC
. It may also be used to
supply peripheral circuits such as dialling or control
circuits. The V
CC
voltage depends on the current
consumed by the IC and the peripheral circuits as shown
by the formula (see also Figs 8 and 9). R
CCint
is the
internal equivalent resistance of the voltage supply point,
and I
rec
is the current consumed by the output stage of the
earpiece amplifier.
V
CC
= V
CC0
R
CCint
×
(I
P
I
rec
)
V
CC0
= V
LN
R
CC
×
I
CC
The DC line current flowing into the set is determined by
the exchange supply voltage (V
exch
), the feeding bridge
resistance (R
exch
), the DC resistance of the telephone line
(R
line
) and the reference voltage (V
ref
). With line currents
below 7.5 mA, the internal reference voltage (generating
V
ref
) is automatically adjusted to a lower value.
This means that more sets can operate in parallel with DC
line voltages (excluding the polarity guard) down to an
absolute minimum voltage of 1.6 V. At currents below
7.5 mA, the circuit has limited transmit and receive levels.
This is called the low voltage area.
Set impedance
In the audio frequency range, the dynamic impedance is
mainly determined by the R
CC
resistor. The equivalent
impedance of the circuits is illustrated in Fig.10.
Transmit amplifier (pins TX+, TX
and GAT)
The TEA1118 and TEA1118A have symmetrical transmit
inputs. The input impedance between pins TX+ and TX
is
equal to 62.5 k
; the input impedance between pins
TX+/TX
and V
EE
is equal 36.5 k
.
The voltage gain from
pins TX+/TX
to pin LN is set at 11.3 dB.
Automatic gain control is provided on this amplifier for line
loss compensation.
The gain of the TEA1118 can be decreased by connecting
an external resistor R
GAT
between pins GAT and REG.
The adjustment range is equal to 6 dB. A capacitor C
GAT
connected between pins GAT and REG can be used to
provide a first-order low-pass filter. The cut-off frequency
corresponds to the time constant C
GAT
× (
R
GATint
// R
GAT
).
R
GATint
is the internal resistor which sets the gain with a
typical value of 27 k
.
Transmit mute (pin TMUTE; TEA1118A only)
The transmit amplifier can be disabled by activating the
transmit mute function. When TMUTE is LOW, the normal
speech mode is entered, depending on the level on MUTE.
When TMUTE is HIGH, the transmit amplifier inputs are
disabled while the DTMF input is enabled (no confidence
tone is provided). The voltage gain between LN and
TX+/TX
is attenuated; the gain reduction is 80 dB.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| TEA1118T | Versatile cordless transmisssion circuit |
| TEA1204T | High efficiency DC/DC converter(高效率DC/DC變換器) |
| TEA1204 | High efficiency DC/DC converter |
| TEA5551 | 1-chip AM radio |
| TEA5551T | 1-chip AM radio |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| TEA1118T | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Versatile cordless transmisssion circuit |
| TEA1118TD-T | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Cordless Phone Circuit |
| TEA1124 | 制造商:TEMIC 制造商全稱:TEMIC Semiconductors 功能描述:Zero Voltage Switch with Fixed Ramp |
| TEA1200TS | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:0.95 V starting DC-to-DC converter with low battery indicator |
| TEA1201TS | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:0.95 V starting basic power unit |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。