|
|
|
부품번호 | TEA1118AT 기능 |
|
|
기능 | Versatile cordless transmisssion circuit | ||
제조업체 | NXP Semiconductors | ||
로고 | |||
전체 24 페이지수
INTEGRATED CIRCUITS
DATA SHEET
TEA1118; TEA1118A
Versatile cordless transmisssion
circuit
Product specification
Supersedes data of 1996 Nov 26
File under Integrated Circuits, IC03
1997 Jul 14
Philips Semiconductors
Versatile cordless transmisssion circuit
Product specification
TEA1118; TEA1118A
handbook, full pagewidth
IR
V−>I
DTMF
TX+
TX−
V−>I
ATTENUATOR
V−>I
V−>I
GAR
QR MUTE
CURRENT
REFERENCE
VCC
LN
REG
TMUTE
TRANSMIT
MUTE
AGC
CIRCUIT
VEE
AGC
LOW VOLTAGE
CIRCUIT
TEA1118AM
TEA1118AT
MBH272
SLPE
Fig.2 Block diagram (TEA1118A).
1997 Jul 14
4
4페이지 Philips Semiconductors
Versatile cordless transmisssion circuit
Product specification
TEA1118; TEA1118A
FUNCTIONAL DESCRIPTION
All data given in this chapter are typical values, except
when otherwise specified.
Supplies (pins LN, SLPE, VCC 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 (Vref)
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 (RVA). It can be
increased by connecting the RVA resistor between
pins REG and SLPE (see Fig.11), or decreased by
connecting the RVA 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 (CREG) which is connected to VEE.
This capacitor, converted into an equivalent inductance
(see Section “Set impedance”), realizes the set impedance
conversion from its DC value (RSLPE) to its AC value
(RCC 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:
VLN = Vref + RSLPE × ISLPE
ISLPE = Iline − ICC − IP − I* = Ish
where:
Iline: line current
ICC: current consumption of the IC
IP: supply current for peripheral circuits
I*: current consumed between LN and VEE
Ish: the excess line current shunted to SLPE (and VEE)
via LN.
The preferred value for RSLPE is 20 Ω. Changing RSLPE 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 VCC. This voltage supply is derived from
the line voltage by means of a resistor (RCC) and must be
decoupled by a capacitor CVCC. It may also be used to
supply peripheral circuits such as dialling or control
circuits. The VCC voltage depends on the current
consumed by the IC and the peripheral circuits as shown
by the formula (see also Figs 8 and 9). RCCint is the
internal equivalent resistance of the voltage supply point,
and Irec is the current consumed by the output stage of the
earpiece amplifier.
VCC = VCC0 − RCCint × (IP − Irec)
VCC0 = VLN − RCC × ICC
The DC line current flowing into the set is determined by
the exchange supply voltage (Vexch), the feeding bridge
resistance (Rexch), the DC resistance of the telephone line
(Rline) and the reference voltage (Vref). With line currents
below 7.5 mA, the internal reference voltage (generating
Vref) 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 RCC 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 kΩ; the input impedance between pins
TX+/TX− and VEE is equal 36.5 kΩ. 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 RGAT between pins GAT and REG.
The adjustment range is equal to 6 dB. A capacitor CGAT
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 CGAT × (RGATint // RGAT).
RGATint is the internal resistor which sets the gain with a
typical value of 27 kΩ.
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.
1997 Jul 14
7
7페이지 | |||
구 성 | 총 24 페이지수 | ||
다운로드 | [ TEA1118AT.PDF 데이터시트 ] |
당사 플랫폼은 키워드, 제품 이름 또는 부품 번호를 사용하여 검색할 수 있는 |
구매 문의 | 일반 IC 문의 : 샘플 및 소량 구매 ----------------------------------------------------------------------- IGBT, TR 모듈, SCR 및 다이오드 모듈을 포함한 광범위한 전력 반도체를 판매합니다. 전력 반도체 전문업체 상호 : 아이지 인터내셔날 사이트 방문 : [ 홈페이지 ] [ 블로그 1 ] [ 블로그 2 ] |
부품번호 | 상세설명 및 기능 | 제조사 |
TEA1118A | Versatile cordless transmisssion circuit | NXP Semiconductors |
TEA1118AM | Versatile cordless transmisssion circuit | NXP Semiconductors |
DataSheet.kr | 2020 | 연락처 | 링크모음 | 검색 | 사이트맵 |