 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
TEA1067T Datasheet(PDF) 5 Page - NXP Semiconductors |
|
||||||||||||||||||||||||||||||
TEA1067T Datasheet(HTML) 5 Page - NXP Semiconductors |
|
|
5 / 28 page  June 1990 5 Philips Semiconductors Product specification Low voltage versatile telephone transmission circuit with dialler interface TEA1067 FUNCTIONAL DESCRIPTION Supply: VCC, LN, SLPE, REG and STAB Power for the TEA1067 and its peripheral circuits is usually obtained from the telephone line. The IC develops its own supply at VCC and regulates its voltage drop. The supply voltage VCC may also be used to supply external circuits e.g. dialling and control circuits. Decoupling of the supply voltage is performed by a capacitor between VCC and VEE while the internal voltage regulator is decoupled by a capacitor between REG and VEE. The DC current drawn by the device will vary in accordance with varying values of the exchange voltage (Vexch), the feeding bridge resistance (Rexch), and the DC resistance of the telephone line (Rline). The TEA1067 has an internal current stabilizer working at a level determined by a 3.6 k Ω resistor connected between STAB and VEE (see Fig.7). When the line current (Iline) is more than 0.5 mA greater than the sum of the IC supply current (ICC) and the current drawn by the peripheral circuitry connected to VCC (Ip) the excess current is shunted to VEE via LN. The regulated voltage on the line terminal (VLN) can be calculated as: VLN =Vref + ISLPE × R9; or VLN = Vref + [(Iline − ICC − 0.5 × 10−3 A) − Ip] × R9 Where Vref is an internally generated temperature compensated reference voltage of 3.6 V and R9 is an external resistor connected between SLPE and VEE. In normal use the value of R9 would be 20 Ω. Changing the value of R9 will also affect microphone gain, DTMF gain, gain control characteristics, side-tone level and maximum output swing on LN, and the DC characteristics (especially at the lower voltages). Under normal conditions, when ISLPE >> ICC + 0.5 mA + Ip, the static behaviour of the circuit is that of a 3.6 V regulator diode with an internal resistance equal to that of R9. In the audio frequency range the dynamic impedance is largely determined by R1. Fig.4 shows the equivalent impedance of the circuit. At line currents below 9 mA the internal reference voltage is automatically adjusted to a lower value (typically 1.6 V at 1 mA). This means that the operation of more sets in parallel is possible with DC line voltages (excluding the polarity guard) down to an absolute minimum voltage of 1.6 V. With line currents below 9 mA the circuit has limited sending and receiving levels. The internal reference voltage can be adjusted by means of an external resistor (RVA). This resistor connected between LN and REG will decrease the internal reference voltage, connected between REG and SLPE it will increase the internal reference voltage. Current (Ip) available from VCC for peripheral circuits depends on the external components used. Fig.10 shows this current for VCC > 2.2 V. If MUTE is LOW when the receiving amplifier is driven the available current is further reduced. Current availability can be increased by connecting the supply IC (TEA1081) in parallel with R1, as shown in Fig.17 (c), or by increasing the DC line voltage by means of an external resistor (RVA) connected between REG and SLPE. |
Similar Part No. - TEA1067T |
|
Similar Description - TEA1067T |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
