TEA2260

TEA2260 STMICROELECTRONICS | Alldatasheet

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SWITCH MODE POWER SUPPLY CONTROLLER June 1992 .POSITIVE AND NEGATIVE CURRENT UP TO 1.2A and – 2A .LOW START-UP CURRENT .DIRECT DRIVE OF THE POWER TRANSIS- TOR .TWO LEVELS TRANSISTOR CURRENT LIMI- TATION .DOUBLE PULSE SUPPRESSION .SOFT-STARTING .UNDER AND OVERVOLTAGE LOCK-OUT .AUTOMATIC STAND-BY MODE RECOGNI- TION .LARGE POWER RANGE CAPABILITY IN STAND-BY (Burst mode) .INTERNAL PWM SIGNAL GENERATOR

DESCRIPTION

The TEA2260/61 is a monolithic integrated circuit for the use in primary part of an off-line switching mode power supply. All functions required for SMPS control under nor- mal operating, transient or abnormal conditions are provided. The capability of working according to the "master- slave" concept, or according to the "primary regu- lation" mode makes the TEA2260/61 very flexible and easy to use. This is particularly true for TV receivers where the IC provides an attractive and low cost solution (no need of stand-by auxiliary power supply). See application note AN376/0490 for detailed information. IS IN GND GND E S TRANSFORMER DEMAGNETIZATION SENSING INPUT SECONDARY PULSES INPUT POWER TRANSISTOR CURRENT LIMITATION INPUT GROUND GROUND ERROR AMPLIFIER INPUT (INVERTING) ERROR AMPLIFIER OUTPUT OVERLOAD INTEGRATION CAPACITOR I MAX V CC OUT GND GND POWER SUPPLY POSITIVE OUTPUT STAGE SUPPLY POWER OUTPUT GROUND GROUND OSCILLATOT RESISTOR OSCILLATOR CAPACITOR SOFT-START CAPACITOR 2261-01.EPS PIN CONNECTIONS BATWING DIP 16 (Plastic Package) ORDER CODES : TEA2260 - TEA2261

REFV (2.49V) POSITIVE OUTPUT STAGE NEGATIVE OUTPUT STAGE REPETITIVE OVERLOAD PROTECTION CURRENT LIMITATION SECONDARY PULSE 0.15V 0.6V2.55V 0.9V 10µ A 45µ A PRIMARY PULSES REGULATION PULSES OVERVOLTAGE PROTECTION 15.7V DEMAGNETIZATION SENSING MODULATORS V 2.49V REF OSCILLATORON(Max.) CCV E SV V +CC OUT GNDIMAXC 2INISCC10 0R + - + -T (60%) SOFT-START - 1 131254381211 109 7 16 15 + 1.2A (Max.) - 2A (Max.) 7.4V 10.3V 2261-04.EPS BLOCK DIAGRAM ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit VCC Power Supply V16-V4, 5, 12, 13 20 V V+ Output Stage Power Supply V15-V4, 5, 12, 13 20 V IOUT + Positive Output Current (source current) 1.5 A IOUT - Negative Output Current (sink current) 2.5 A Tj Operating Junction Temperature 150 oC Tstg Storage Temperature Range -40, +150 oC 2261-01.TBL THERMAL DATA R th (j-c) Junction-case Thermal Resistance 11 oC/W R th (j-a) Junction-ambient Thermal Resistance 45 oC/W * Soldered on a 35µm, 40cm2 board copper area. 2261-02.TBL 50 100 1500 P (W) tot T ( C)AMB o

45 C/Wo

2261-05.EPS MAXIMUM POWER DISSIPATION TEA2260 - TEA2261

RECOMMENDED OPERATING CONDITIONS Symbol Parameter Min. Typ. Max. Unit VCC Power Supply V CC stop 12 V CC max V IOUT + Positive Output Current (source current) 1.2 A IOUT - Negative Output Current (sink current) 2.0 A IOUT + Average Positive Output Current 0.6 A IOUT - Average Negative Output Current 0.6 A Foper Operating Frequency 10 100 kHz VIN Input Pulses Amplitude (Pin 2) 1.5 2.5 4.5 V R OSC Oscillator Resistor Range 20 150 k Ω C OSC Oscillator Capacitor Range 0.47 4.7 nF C1 Soft-starting Capacitor Range 0.047 1 µF C2 Overload Integration Capacitor 0.047 1 µF C2/C1 Ratio C2/C1 (C2 must be ≥ C1) 1 Tamb Operating Ambient Temperature -20 70 oC 2261-03.TBL ELECTRICAL CHARACTERISTICS (Tamb = 25oC, VCC =12V, unless otherwise specified) Symbol Parameter Min. Typ. Max. Unit POWER SUPPLY VCC(start) Starting Voltage (VCC increasing) 9.3 10.3 11.3 V VCC(stop) Stopping Voltage (VCC decreasing) 6.4 7.4 8.4 V Hyst VCC Hysteresis (VCC(start) - VCC(Stop)) 2.4 2.9 V ICC(start) Starting Current (VCC = 9V) 0.7 1.4 mA ICC Supply Current (VCC = 12V) 7.5 15 mA VCC(max) Overvoltage Threshold on VCC 15 15.7 V ICC(over) Supply Current after Overvoltage Detection (VCC = 17V) 26 35 42 mA OSCILLATOR / PWM SECTION Delta F F Accuracy (ROSC = 68kΩ , COSC = 1nF) 10 % tON max Maximum Duty Cycle in Primary Regulation Mode 50 60 70 % ERROR AMPLIFIER SECTION AVO Open Loop Gain 75 dB Fug Unity Gain Frequency 550 kHz ISC Short Circuit Output Current (Pin 7 connected to ground) 2 mA IBE E Input Bias Current (Pin 6) 0.08 µA VREF Internal Voltage Reference (connected to error amplifier input and not directly accessible) 2.34 2.49 2.64 V INPUT SECTION VIN IN Input Threshold (Pin 2) 0.6 0.85 1.2 V VIS IS Input Threshold (Pin 1) 0.15 V IBIN IN Input Bias Current 0.3 µA IBIS IS Input Bias Current 0.4 µA CURRENT LIMITATION SECTION VIM1 First Current Limitation Threshold 558 600 642 mV VIM2 Second Current Limitation Threshold 837 900 963 mV Δ VIM Thresholds Difference VIM2 - VIM1 300 mV VC2 Lock-out Threshold on Pin C2 2.25 2.55 2.85 V IDC2 Capacitor C2 Discharge Current 10 µA ICC2 Capacitor C2 Charge Current 45 µA IBI(max) Maximum Input Bias Current (Pin 3) 0.2 µA 2261-04.TBL TEA2260 - TEA2261

The TEA2260/61 is an off-line switch mode power supply controller. The synchronization function and the specific operation in stand-by mode make it well adapted to video applications such as TV sets, VCRs, monitors, etc... The TEA2260/61 can be used in two types of architectures : - Master/slave architecture. In this case, the TEA2260/61 drives the power transistor accord- ing to the pulse width modulated signals gener- ated by the secondary located master circuit. A pulse transformer provides the feedback (see Figure 1). - Conventional architecture with linear feedback signal (feedback sources : optocoupler or trans- former winding) (see Figure 2). Using the TEA2260/61, the stand-by auxiliary power supply, often realized with a small but costly 50Hz transformer, is no longer necessary. The burst mode operation of the TEA2260/61 makes possible the control of very low output power (down to less than 1W) with the main power transformer. When used in a master/slave architecture, the TEA2260/61 and also the power transistor turn-off can be easily synchronized with the line trans- former. The switching noise cannot disturb the picture in this case. As an S.M.P .S. controller, the TEA2260/61 features the following functions : - Power supply start-up (with soft-start) - PWM generator - Direct power transistor drive (+1.2A, -2.0A) - Safety functions : pulse by pulse current limita- tion, output power limitation, over and under volt- age lock-out. S.M.P .S. OPERATING DESCRIPTION Starting Mode - Stand By Mode Power for circuit supply is taken from the mains through a high value resistor before starting. As long as V CC of the TEA2260/61 is below VCC start, the quiescent current is very low (typically 0.7mA) and the electrolytic capacitor across VCC is linearly charged. When VCC reaches VCC start (typically 10.3V), the circuit starts, generating output pulses with a soft-starting. Then the SMPS goes into the stand-by mode and the output voltage is a percen- tage of the nominal output voltage (eg. 80%). For this the TEA2260/61 contains all the functions required for primary mode regulation : a fixed fre- quency oscillator, a voltage reference, an error amplifier and a pulse width modulator (PWM). For transmission of low power with a good effi- ciency in stand-by, an automatic burst generation system is used, in order to avoid audible noise. Normal Mode (secondary regulation) The normal operating of the TV set is obtained by sending to the TEA2260/61 regulation pulses gen- erated by a regulator located in the secondary side of the power supply. This architecture uses the "Master-slave Concept", advantages of which are now well-known espe- cially the very high efficiency in stand-by mode, and the accurate regulation in normal mode. Stand-by mode or normal mode are obtained by supplying or not the secondary regulator. This can be ordonnered for exemple by a microprocessor in relation with the remote control unit. Regulation pulses are applied to the TEA2260/61 through a small pulse-transformer to the IN input (Pin 2). This input is sensitive to positive square pulses. The typical threshold of this input is 0.85V. The frequency of pulses coming from the secon- dary regulator can be lower or higher than the frequency of the starting oscillator. The TEA2260/61 has no soft-starting system when it receives pulses from the secondary. The soft- starting has to be located in the secondary regula- tor. Due to the principle of the primary regulation, pulses generated by the starting system automat- ically disappear when the voltage delivered by the SMPS increases. Stand-by Mode - Normal Mode Transition During the transition there are simultaneously pulses coming from the primary and secondary regulators. These signals are not synchronized and some care has to be taken to ensure the safety of the switching power transistor. A very sure and simple way consist in checking the transformer demagnetization state. - A primary pulse is taken in account only if the transformer is demagnetized after a conduction of the power transistor required by the secondary regulator. - A secondary pulse is taken in account only if the transformer is demagnetized after a conduction of the power transistor required by the primary regulator. With this arrangem ent the switching safety area of the power transistor is respected and there is no risk of transformer magnetization. The magnetization state of the transformer is checked by sensing the voltage across a winding of the transformer (generally the same which sup- plies the TEA2261). This is made by connecting a resistor between this winding and the demagneti- zation sensing input of the circuit (Pin 1). TEA2260 - TEA2261

S.M.P.S. starting First threshold reached VIM1 Pulse by pulse current limiting C charged2 V < 2.6VC2 CCV max reached S.M.P.S. stopping V stop reached N = N + 1 CC Normal operating C discharged Restart number = 3 Definitive stopping Reset C discharged N N Y N N Y Y Y N Y Y N Second threshold reached VIM2 2261-06.EPS SECURITY FLOW-CHART (TEA2260) SECURITY FUNCTIONS OF THE TEA2260 (see flow-chart below) -Undervoltage detection. This protection works in association with the starting device "VCC switch" (see paragraph Starting-mode - standby mode). If VCC is lower than VCC stop (typically 7.4V) output pulses are inhibited, in order to avoid wrong operation of the power supply or bad power transistor drive. -Overvoltage detection. If V CC exceeds VCC max (typically 15.7V) output pulses are inhibited. Re- starting of the power supply is obtained by reduc- ing V CC below VCC stop. -Current limitation of the power transistor. The current is measured by a shunt resistor. A double threshold system is used : - When the first threshold (VIM1) is reached, the conduction of the power transistor is stopped until the end of the period : a new conduction signal is needed to obtain conduction again. - Furthermore as long as the first threshold is reached (it means during several periods), an external capacitor C 2 is charged. When the voltage across the capacitor reaches VC2 (typi- cally 2.55V) the output is inhibited. This is called the "repetitive overload protection". If the over- load diseappears before V C2 is reached, C2 is discharged, so transient overloads are toler- ated. - Second current limitation threshold (VIM2). When this threshold is reached the output of the circuit is immediatly inhibited. This protection is helpfull in case of hard overload for example to avoid the magnetization of the transformer. - Restart of the power supply. After stopping due to V C2 , VIM2, VCC Max or VCC stop triggering, re- start of the power supply can be obtained by the normal operating of the "VCC switch" but thanks to an integrted counter, if normal restart cannot be obtained after three trials, the circuit is defini- tively stopped. In this case it is necessary to reduce V CC below approximately 5V to reset the circuit. From a practical point of view, it means that the power supply has to be temporarily dis- connected from any power source to get the restart. TEA2260 - TEA2261

SECURITY FUNCTIONS OF THE TEA2261 (see flow-chart below) S.M.P.S. starting First threshold reached VIM1 V < 2.6VC2 CCV max reached Normal operating C discharged Definitive stopping N N Y N N Y Y Y N Y Pulse by pulse current limiting C charged2 C charged S.M.P.S. stopped V < 2.6VC2 Y Reset C discharged N Second threshold reached VIM2 2261-07.EPS SECURITY FLOW-CHART (TEA2261) -Undervoltage detection. This protection works in association with the starting device "VCC switch" (see paragraph Starting-mode - standby mode). If VCC is lower than VCC stop (typically 7.4V) output pulses are inhibited, in order to avoid wrong operation of the power supply or bad power transistor drive. -Overvoltage detection. If V CC exceeds VCC max (typically 15.7V) output pulses are inhibited and the external capacitor C 2 is charged as long as VCC is higher than VCC stop. Restarting of the power supply is obtained by reducing VCC below VCC stop except if the voltage across C2 reaches VC2 (typically 2.55V) (refer to "Restart of the power supply" paragraph).In this last case, the circuit is definitively stopped. -Current limitation of the power transistor. The current is measured by a shunt resistor. A double threshold system is used : - When the first threshold (V IM1) is reached, the conduction of the power transistor is stopped until the end of the period : a new conduction signal is needed to obtain conduction again. - Furthermore as long as the first threshold is reached (it means during several periods), an external capacitor C 2 is charged. When the voltage across the capacitor reaches VC2 (typi- cally 2.55V) the output is inhibited. This is called the "repetitive overload protection". If the over- load diseappears before VC2 is reached, C2 is discharged, so transient overloads are toler- ated. - Second current limitation threshold (V IM2). When this threshold is reached the output of the circuit is immediatly inhibited. This protection is helpfull in case of hard overload for example to avoid the magnetization of the transformer. - Restart of the power supply. After stopping due to V IM2, VCC Max or VCC stop triggering, restart of the power supply can be obtained by the normal operating of the "VCC switch" VCC switch se- quency from VCC stop to VCC start . After stopping due to VC2 threshold reaching, the circuit is de- finitively stopped. In this case it is necessary to reduce V CC below approximately 5V to reset the circuit. From a practical point of view, it means that the power supply has to be temporarily dis- connected from any power source to get the restart. TEA2260 - TEA2261

Secondary ground (isolated from mains) Small signal secondary ground

170 VAC

270 VAC

470µ F 25V 1000µ F 25V 1000µ F 25V BA157 1N4148 100pF 2.7nF 1kV BY299 47µ F BZX85-3V0 2.2µ H 1nF 1nF 2.2µ F 16V SGSF 344 31 3 71 7 Stand-by control 47nF 1N4148 150pF Sync. input 10µ F 16V 1873 2465 7 6 4 5 12 13 16 15 11 10 2 9 8 3 14 1 BC547C TEA2260/61 TEA5170 Ω120k Ω2.2k Ω10k Ω k ΩΩ 6.8k ΩΩ Ω Ω Ω Ω Ω Ω 22k 100 Ω Ω Ω Ω10 Ω1k Ω1kΩ Ω4.7k OUT 2.2 /0.5W 47kΩ 135V 0.8A 7.5V 12V 0.5A 25V 1.2nF 560 pF 100k 220 16W 0.135 /1W 330 nF 330 nF 22k 3.3 nF 150µ F 385V 22k 330µ F 25V P : 140W f : 32kHz 82k 270 100µ F 250V 330 Ω 1nF 2261-08.EPS TYPICAL APPLICATION (Master/slavearchitecture) TV - SET SMPS (with TEA5170) Input voltage range 170VAC – 270VAC Input DC voltage range 210VDC – 370VDC Output power in normal mode 25W < P O < 140W Output power in stand by mode 2W < P O < 45W Operating frequency 32 kHz Efficiency at full load > 80% Efficiency in stand by mode > 50% Short circuit protected Open load protected Long duration overload protected Complete shutdown after repetitive default detection Load regulation (VDC = 310V) Output 135V (± 0.18%) → (I135 : 0.01A to 0.8A ; I25 = 1A) Line regulation Output 135V (± 0.13%) → (210V < VDC < 370V) TEA2260 - TEA2261

Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No licence is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. © 1994 SGS-THOMSON Microelectronics - All Rights Reserved Purchase of I 2C Components of SGS-THOMSON Microelectronics, conveys a license under the Philips I2C Patent. Rights to use these components in a I2C system, is granted provided that the system conforms to the I2C Standard Specifications as defined by Philips. SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - China - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A. I L B e D b Z e3 F E PM-DIP16.EPS PACKAGE MECHANICAL DATA

16 PINS - PLASTIC DIP

Dimensions Millimeters Inches a1 0.51 0.020 B 0.77 1.65 0.030 0.065 b 0.5 0.020 b1 0.25 0.010 D 20 0.787 E 8.5 0.335 e 2.54 0.100 e3 17.78 0.700 F 7.1 0.280 i 5.1 0.201 L 3.3 0.130 Z 1.27 0.050 DIP16.TBL TEA2260 - TEA2261