GSG 勁力 半導体 Gunter Semiconductor GmbH TFA3354 EDITION 09/00 Control and Monitoring IC for electronic ballast operating fluorescent lamps. It triggers, monitors and turns-off the RF oscillation dependent on several control- and guarding functions. For inquiry please contact : China Tel: 0086-755-3200442 Fax: 0086-755-3355520 Hong Kong Tel : 00852-26190748 Fax: 00852-24948080 e-mail [email protected] Technical Data TFA3354 Edition 09/00 IC for Electronic Ballasts Short Description Features The bipolar monolithic integrated circuit triggers, monitors and turns-off RF-oscillation of an electronic ballast for fluorescent lamps dependent on several control- and monitoring functions. • Minimum wiring complexity • Overtemperature protection without external components • Malfunction detection • Timer output • Automatical re-ignition after lamp change Package 9.4 ± 0.2 6.4 ≤ 1.27 +0.2 -0.1 ≤ 1.40 3.5 ≥ 0.51 +1.0 -0.5 3.6 ≤ 5.1 +0.2 -0.1 • DIP 8 ≤ 0.98 0.27 7.50 0.47 ±0.12 2.50 +0.09 -0.07 0.25 M 7.9 . . . 9.7 8 7 6 5 1 2 3 4 6.2 ± 0.2 4.98 ± 0.1 ≤ 2.00 0.2 ± 0.1 0.15 ≤ 0.635 09/00 + 0.2 - 0.1 0...10° 4.0 1.27 0.42 ±0.07 8 7 6 5 1 2 3 4 0.25 M ≥ 0.3 0.20 ± 0.05 1.45 ± 0.1 • SOP 8 1 Pinning Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 Pin 6 Pin 7 Pin 8 TM CT TR GND EI LW S VCC temperature mode selection clock generator trigger output, turn-off attenuation, oscillation detector connection to ground error indication input input of lamp change switching output of the timer supply voltage Block diagram V CC S 7 8 POWER SUPPLY UNIT REFERENCE VOLTAGE TEMPERATURE MODE SELECTION 5 6 TIMER OUTPUT RESET ERROR STORAGE + RELEASE TRIGGER STOP ERROR DETECTION + LOGIC TURN - OFF DELAY COUNTER SHORTENING FOR TEST STARTING CONTROL OVERTEMPERATURE SENSOR EI LW TRIGGER OUTPUT CLOCK GENERATOR ATTENUATION OF OSCILLATIONS CLOCK REGIME OSCILLATION DETECTOR 1 TM 3 2 CT LOGIC FOR TRIGGER- AND TURN-OFF REGIME TURN - OFF MEMORY TFA 3354 4 TR Characteristics of the IC TFA3354 • The TFA3354 is a control- and monitoring-IC to drive an electronic ballast for fluorescent lamps. • The IC actuates the oscillation of a self-oscillating circuit for generation of RF-shaped lamp current by means of trigger pulses. After successful excitation the oscillation is monitored and further trigger pulses are blocked. • The IC has a timer with low-active output which is activated for one second after supply voltage was applied. The switching output is effective for pre-heating and ignition systems. • The IC consists an error indication input. In case of error indication the IC stops oscillation. Enquiry cycles realize interference reduction. • After lamp change the IC starts oscillation again. • The IC protects from overtemperature cutting oscillation. It is programmable when the oscillator circuit shall be triggered again. 2 09/00 TFA3354 Functional Description At the moment of current feeding at terminal VCC, the IC generates the supply voltage via backup capacitor externally connected. As soon as an internal switching threshold of 7 V is reached, trigger pulses are delivered at the output TR with a repetition instalment of 960 µs. After successful triggering of the oscillator circuit, an oscillation detector guarantees blocking of further trigger pulses. It identifies a stable oscillating process, after a minimum of oscillations is detected per timing. As soon as a switching threshold of 8 V is reached, all logic units are reset and the timer output S is activated as well. The IC starts a counter, which interrups the control after one second. Furthermore, the IC monitors the temperature and the oscillation circuit from a supply voltage of 8 V. The comparator input EI is useful for error detection. Voltage > 3.75 V, applied at EI, are evaluated as error signals. The error signal is enqired and registered within a cycle repeating every 960 µs. After registration of the error signal, a counter starts to generate a delay of one second. After this delay time, the voltage at EI is evaluated again. The error storage is set only after a second error, appearing within a directly following evaluation cycle. This error storage is resettable by a short-time power supply disconnection, or with input LW connected via a change of lamp. The error storing causes the cutting further triggers and the control of the turn-off transistor as well, which turns the output TR to ground. Therefore, the turn-off transistor prevents the control of the oscillator circuit, attenuating it extremly quickly. Thereby, the current consumption increases by the control of the turn-off transistor. This current amounts more than 5 mA, that the supply voltage across the backup capacitor at pin VCC breaks down (because nominal current feed is less 5 mA). With a switching threshold of 6 V, the control current of the turn-off transistor is switched off, that enables the supply voltage to rise up to the limiting voltage. Because the trigger pulse gate, blocked by the error memory, the oscillation can’t start again. With error storing and attenuation of the oscillation by overtemperature it can be defined via selection of the temperature mode, whether the oscillation is automatically triggered after cooling-down of the assembly, or only after mains disconnection. Pin Description Pin 1 TM Temperature mode selection As soon as the chip temperature range of 95 °C to 115 °C is reached, the error storage is set. When input TM is open, the error storing happens only after identification of an overtemperature and a second enquiry, delayed by one second but showing the same result and causing attenuation of the oscillation. The multiple enquiry reduces the possibility of coupling in distortions for temperatures in the close neighbourhood of the temperature switching level. A new start is only possible after turn-off the mains voltage. When the input TM is connected to ground, the IC triggers the oscillation again after approximately 10 degrees decreasing of the chip temperature. Please note, that no enquiry cycle is duty in this mode. Pin 2 CT Clock Generator A clock generator delivers clock pulses of 10 µs pulse width and a repetition frequency of 33 kHz by means of defined reversing charges of the ramp capacitor connected at pin CT with a nominal value of 82 pF. All time lapses within the IC are derived from this clock. A variation of capacity of the external capacitor affects all time responses except the trigger pulse width. 09/00 TFA3354 3 Pin 3 TR Trigger and Turn-off Output This pin realizes three functions: • Delivery of trigger pulses with a repetition instalment of 960 µs, a pulse width of 1 µs and a current flow of 600 mA with 10 Ω resistance. • Monitoring of the control signals up to a frequency of 100 kHz and a minimum amplitude of 400 mV. The oscillation detector gates trigger pulses, if a minimum three periode burst indicated during the trigger pulse repetition rate. • Attenuation of the oscillations by a turn-off transistor with a low saturation voltage. Negative pulses may be applied at pin TR according the specification. Negative voltage peaks can cause an increase of the current consumption. An external Schottky diode between TR and ground prevents this. Pin 4 GND Connection to ground Pin 5 EI Error Indication At pin 5 it is possible to indicate different error values. A static error signal greater than 3.75 V, which is supplied by a suitable network at pin 5 releases after one second by means of an error enquiry cycle the storage of the error. Furthermore the IC allows to supervise high-frequency oscillations. An elaborate enquiry routine has been set up for secure and reliable acquisition of errors under consideration of distortions. This routine consists of the valuation time of 840 µs with following evaluation time of 120 µs. These two periods make the enquiry cycle repeating continuously, when no error signal is stored. Signals with an amplitude > 3.75 V and a minimum duration of 1 µs are valuated as errors. If such events happen at least 4 times within a time window of 840 µs, or a level > 3.75 V is statically applied, a counter starts to realize a delay time of one second. If those signals are detected again in the following valuation cycle, the error memory is setted. This enquiry system saves that the RF-amplitude of the oscillating frequency is supervised, so that feed backs of damaged lamps on the oscillation circuit would be detected. The kind of lamp damage is depending on the type and sample of lamp. That is the reason for an adaptive network for error detection, therefore the input EI is universal applicable. Pin 6 LW Input of Lamp Change This input serves to detect a lamp change and cause a re-start with simultaneous reset of the error memory. Input LW detects whether a lamp is connected, when a voltage > 4.25 V is applied. A voltage < 3.25 V indicates a lamp as removed. Is a lamp exchanged after a stored error, the error memory is reset and the trigger stop is activated. The circuit is blocked without lamp. By removal a lamp the trigger gate is opened. With a normal lamp change under operational conditions, triggers are continuously generated with lamp removed, therefore, the circuit starts oscillation immediately by exchange of lamp. The switching level for lamp change will be provided by a special circuitry. For internal testing purposes at the input LW will be applied a special test level that decreases the internal time response by factor 16. This divider factor is active, if VLW is more than 2 V above VCC, but limited by max.15 V. Pay attention that the voltage difference between VCC and VLW do not has to increase above 6 V also in case of supply voltage break down. Pin 7 S Switching Output The switching output enables the control of the preheat duration of the coiled filament by means of an additional circuit to be selected by the customer. The switching output is an open collector output which is low active for one second during the phase of start. It is able to drive a maximum current of 1 mA at a typical saturation voltage of 200 mV. 4 09/00 TFA3354 Pin 8 VCC Supply voltage The voltage at the VCC-terminal is limited at typ. 11.4 V by the internal power supply circuit. Therefore it is possible to apply the power supply directly by mains with dropping resistor and backup capacitor. The current feed should be choiced high enough for the operation of the voltage limiting. For save operation of the IC the value of VCC has to be never decreased behind a level of 6.5 V. An additional requirement is the increasing of VCC over 8 V at least for a moment. Only under these conditions a proof error storage and a defined reaction of the turn-off transistor is guaranteed. Absolute Maximum Ratings Pin Symbol current consumption VCC peak current for t< 100 µs max unit ICCeff 20 mA VCC ICCM 100 mA input voltage error indicator EI VErr -0.3 VCC V input voltage lamp exchange input LW VLW -0.3 15 V voltage difference between VLW and VCC for divider factor 16 via LW LW VLW - VCC 6 V input current at pin TM TM ITM 1 mA negative current load for t<1µs with max. repeat frequency = 200kHz TR ITR(neg.) switching output current S IS 1 mA junction temperature Tj 150 °C storage temperature Tstg -50 150 °C ambient temperature Tamb -20 120 °C ESD protection VESD 2 kV 09/00 TFA3354 min -500 mA 5 Characteristics with Tamb = 25 °C, VCC = 10 V, unless specified otherwise Pin min typ max unit 10.8 11.4 12 V 1.25 1.5 mA range for internal voltage limitation VCC Vlim quiescent current consumption VCC ICC(on) trigger repeat rate with CClock = 82pF TR tTRW 900 1000 1100 µs output pulse current on 10 Ω TR ITRM 400 650 850 mA output pulse width with 90% amplitude TR tTR 0.6 0.9 1.5 µs saturation voltage of turn-off transistor with I=450 mA TR VTRsat 380 500 mV saturation voltage of switching output S VSsat 0.2 0.45 V response level of error voltage EI KOL 3.60 3.75 3.90 V 95 105 115 °C 3.25 V VCC V switching point of overtemperature turn-off 6 Symbol TS switching range to indicate a lamp as removed LW VLE switching range to indicate a lamp as applied LW VLV 4.25 09/00 TFA3354 Values for Information (CClock = 82 pF) Threshold for connecting the trigger pulses during build-up phase 7 V Threshold for release of the internal reset 8 V Threshold for switching-off the control of the turn-off transistor with set error memory 6 V Delay of response with error detection 1 s Duration for activation switching output 1 s 840 µs Control current of the turn-off transistor 10 mA Temperature hysteresis for re-ignition after overtemperature switch-off ( pin TM is connected to ground ) 10 °C Duration needed for rating at least 4 pulse-shaped distortions or a static error signal with twice interrogation within delay time 1 sec 09/00 TFA3354 7 Dependences Current consumption vs. supply voltage ICC ( mA ) 1.8 1.4 1.2 1 0.8 6 5 7 8 9 10 VCC ( V ) 12 Ta ( °C ) 100 Voltage limiting vs. temperature ICC = 5 mA Vlim ( V ) 12.0 11.4 11.2 11.0 10.8 10.6 -20 8 -10 0 10 20 30 40 50 60 70 09/00 TFA3354 Trigger current at 10 Ω vs. temperature, VCC = 10 V ITRM ( mA ) 850 700 650 600 550 500 450 400 -30 -20 -10 0 10 20 30 40 50 60 70 Ta ( °C ) 100 Trigger pulse width (90% amplitude) vs. temperature, VCC = 10 V t ( µs ) 1.5 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 -20 09/00 TFA3354 -10 0 10 20 30 40 50 60 70 Ta ( °C ) 100 9 Static overload threshold VCC = 10 V V5 ( V ) 3.90 3.80 3.75 3.70 3.65 3.60 -20 -10 0 10 20 30 40 50 60 70 Ta ( °C ) 100 Ta ( °C ) 100 Timer output saturation voltage at 1mA VCC = 10 V Vsat ( mV ) 450 300 250 200 150 100 -20 10 -10 0 10 20 30 40 50 60 70 09/00 TFA3354 Principle Circuit Diagram ST PREHEAT CONTROL CIRCUIT ~ - + ~ EI EI LW 5 4 6 3 TFA 3354 ST VCC 7 8 2 GND TR NETWORK FOR ERROR SIGNAL LW NETWORK FOR LAMP CHANGE CT TM 1 D Copying is generally permitted, indicating the source. However, our consent must be obtained in all cases. MEGAXESS reserves the right to make changes in specifications at any time and without notice. The information and suggestions are given without obligation and cannot give rise to any liability, they do not indicate the availability of the components mentioned. The information included herein is believed to be accurate and reliable. However, MEGAXESS assumes no responsibility for its use; nor for any infringements of patents or of other rights of third parties which may result from its use. Megaxess GmbH Deutschland • POB 1370 • 15236 Frankfurt(Oder) • Germany Phone +49 335 2005 • FAX +49 335 3251 • Internet http://www. megaxess.de 09/00 TFA3354 11