U4078B TEMIC | Alldatasheet
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Features
/C0068Suitable for the specification: FTZ, 1TR2 and ETR2 /C0068Rectifier bridge /C0068Z-diode /C0068Amplitude detection /C0068Detection of ringing signal i.e., sine-, triangle-, or rectangular (tone ringing) signal /C0068High-voltage bipolar technology /C0068Compact surface mount package (SO8) Benefits /C0068High efficient power transfer Hysteresis and power supply Pulse shaping38 kHz 1.5 k/C0087 180 k/C0087 output /C0109C supply 1 /C0109F 47 pF 22 /C0109F 463 GND TH OSC MS ST V B a b a/C0512 b/C0512 /C0024 92 7460 e Figure 1. Block diagram with external circuit
TELEFUNKEN SemiconductorsU4078B Pin Description Pin Symbol Function 1, 8 a/C0512, b/C0512 AC ringing signal input
2 V B Output to charging capacitor
(for supply)
3 TH Comparator threshold adjustment
4 MS Mode selection: inductive or
5 ST Switching transistor connection
6 OSC RC circuit for internal oscillator
7 GND Ground
The ringing ac signal, supplied by the exchange via lines a, b, is identified by a comparator circuit. An integrated oscillator, generates a 38 kHz clock signal, f clock, via a coupled 2:1 divider. With the help of the external RC circuit, oscillation frequency is set at Pin 6. A PNP-transistor connected at Pin 5 enables the power transmission (transfer) in inductive or opto-coupler mode, which is selected at Pin 4. For inductive mode, Pin 4 is open, whereas for opto-coupler mode, Pin 4 is connected to GND (Pin 7). Pin 1,8: Power Supply – a/C0512, b/C0512 Pins 1 and 8 connect the circuit with the ac ringing signal supplied by the exchange via lines a and b. A 1µF decoupling capacitor of 1 µF value together with a series resistance (1.5 kΩ) protect the circuit from overload across Pins 1 and 8. The circuit features the following overload protection across the a/C0512, b/C0512 terminals: 1) It can withstand a voltage of 110 V @ 50 Hz for maximum time of 15 seconds. 2) Testing of the circuit according to figure 2 does not destroy the circuit under following conditions: Charging voltage of surge capacitance: V CS = 2 kV Pulse shape: 10/700 µs Pulse sequence: 30 s No. of surges: 10 Polarity change after 5 surges Pin 2: Charging Capacitor (power supply filtering) After the rectification of the ringing ac signal across the bridge circuit, the smoothing of the power supply is provided by the external capacitance at Pin 2 (22 nF). Pin 3: Comparator Threshold /C0042 TH Comparator threshold/C0042as regards the ringing voltage/C0042 is set at ca. 12.5 V . Switching threshold can be increased or decreased by connecting a resistance at Pin 3 w.r.t. GND. Pin 4: Mode Selection /C0042 MS The ringing ac signal transfer (transmission) without potential loss occurs either via an inductive or opto-coupler mode. Pin 4 is set to a high state by an internal power source of 4 µA (approximately). This switches the output (Pin 5) to an operating state for the inductive mode. In case of opto-coupler mode, Pin 4 is connected to the ground (Pin 7). Pin 5: Switching Transistor Connection An external PNP transistor, whose emitter is at VS (Pin 2) potential, serves to control the inductive or opto-coupler mode by connecting the base of the transistor with Pin 5. In case of inductive mode, the signal, f clock is interrupted for the duration of tpulse = 32/fclock, with every transition (rise or fall) of the ringing ac signal, fring. During the interruption, the setting at Pin 5 is such that the coil is critically damped (attenuated), whereas a current of 10 µA flows when the transistor at Pin 5 is switched on during the following t pulse up to the next edge of the pulse. In case of opto-coupler mode, the external transistor is switched on for a period of tpulse = 32/fclock with every flank of the pulse of fring. Pin 5 is at high resistance upto the next edge (flank) of the transition pulse of the ringing ac signal.
TELEFUNKEN SemiconductorsU4078B Time Sequence Internal clock frequency without RC tolerance tclock During this time, a clock signal is given at Pin 5 (ST).Pin 4 is open or ST is high ohmic. (MS=GND) t pulse By every polarity change of the call signal and MS open, the clock signal is interrupted for a time duration t pulse = 32/f clock. During interruption, the signal at ST (Pin5) is of such a value that the coil is critically attenuated (damped). I S (PNP) = IST /C0091 10 µA A current of IST /C0120 150 µA is drawn from Pin 5 (ST) by every polarity change whereby MS is grounded. ÉÉ ÉÉ É É É É É É ÉÉ ÉÉ ÉÉ ÉÉ ÉÉ ÉÉ É É É É É É É É ÉÉ ÉÉ ÉÉ ÉÉ Call signal ST MS = open ST MS = 0 tcycle tpuls e t92 7461 e 92 7471 e t 2. Phase1. Phase ST fcycle Current sequence at Pin 5 with an external PNP transistor connected as shown in figure 1. (fclock = 38 kHz)
Ordering Information
TELEFUNKEN Semiconductors U4078B Ozone Depleting Substances Policy Statement It is the policy of TEMIC TELEFUNKEN microelectronic GmbH to 1. Meet all present and future national and international statutory requirements. 2. Regularly and continuously improve the performance of our products, processes, distribution and operating systems with respect to their impact on the health and safety of our employees and the public, as well as their impact on the environment. It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as ozone depleting substances (ODSs). The Montreal Protocol (1987) and its London Amendments (1990) intend to severely restrict the use of ODSs and forbid their use within the next ten years. Various national and international initiatives are pressing for an earlier ban on these substances. TEMIC TELEFUNKEN microelectronic GmbH semiconductor division has been able to use its policy of continuous improvements to eliminate the use of ODSs listed in the following documents. 1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively 2. Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental Protection Agency (EPA) in the USA 3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C (transitional substances) respectively. TEMIC can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain such substances. We reserve the right to make changes to improve technical design and may do so without further notice. Parameters can vary in different applications. All operating parameters must be validated for each customer application by the customer. Should the buyer use TEMIC products for any unintended or unauthorized application, the buyer shall indemnify TEMIC against all claims, costs, damages, and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death associated with such unintended or unauthorized use. TEMIC TELEFUNKEN microelectronic GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany Telephone: 49 (0)7131 67 2831, Fax number: 49 (0)7131 67 2423