Da ta sheet, V2.0, 1 F eb 2002 PWM-FF IC ICE2AS01/S01G ICE2BS01/S01G Off-Line SMPS Current Mode Controller P o w e r M a n a g em e n t & S u p p l y N e v e r s t o p t h i n k i n g . ICE2AS01/G ICE2BS01/G Revision History: 2002-02-01 Datasheet Previous Version: Page Subjects (major changes since last revision) For questions on technology, delivery and prices please contact the Infineon Technologies Offices in Germany or the Infineon Technologies Companies and Representatives worldwide: see our webpage at http:// www.infineon.com CoolMOS™, CoolSET™ are trademarks of Infineon Technologies AG. Edition 2002-02-01 Published by Infineon Technologies AG, St.-Martin-Strasse 53, D-81541 München © Infineon Technologies AG 1999. All Rights Reserved. Attention please! The information herein is given to describe certain components and shall not be considered as warranted characteristics. Terms of delivery and rights to technical change reserved. We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding circuits, descriptions and charts stated herein. Infineon Technologies is an approved CECC manufacturer. Information For further information on technology, delivery terms and conditions and prices please contact your nearest Infineon Technologies Office in Germany or our Infineon Technologies Representatives worldwide (see address list). Warnings Due to technical requirements components may contain dangerous substances. For information on the types in question please contact your nearest Infineon Technologies Office. Infineon Technologies Components may only be used in life-support devices or systems with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system, or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body, or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered. ICE2AS01/G ICE2BS01/G Off-Line SMPS Current Mode Controller Product Highlights P-DIP-8-4 • Enhanced Protection Functions all with Auto Restart • Lowest Standby Power Dissipation • Very Accurate Current Limiting P-DSO-8-3 Features Description • • • • • This stand alone controller provides several special enhancements to satisfy the needs for low power standby and protection features. In standby mode frequency reduction is used to lower the power consumption and provide a stable output voltage in this mode. The frequency reduction is limited to 20kHz / 21.5 kHz (typ.) to avoid audible noise. In case of failure modes like open loop, overvoltage or overload due to short circuit the device switches in Auto Restart Mode which is controlled by the internal protection unit. By means of the internal precise peak current limitation the dimension of the transformer and the secondary diode can be lower which leads to more cost efficiency. • • • • • • • • Only few external Components required Input Undervoltage Lockout 67kHz/100kHz fixed Switching Frequency Max Duty Cycle 72% Low Power Standby Mode to support “Blue Angle” Norm Latched Thermal Shut Down Overload and Open Loop Protection Overvoltage Protection during Auto Restart Adjustable Peak Current Limitation via External Resistor Overall Tolerance of Current Limiting < ±5% Internal Leading Edge Blanking Soft Start Soft Switching for Low EMI Typical Application + Snubber RStart-up 85 ... 270 VAC Converter DC Output - CVCC VCC Feedback Low Power StandBy Power Management Gate SoftS PWM Controller Current Mode Soft-Start Control CSoft Start Isense Precise Low Tolerance Peak Current Limitation RSense FB Protection Unit Feedback GND ICE2AS01 / ICE2BS01 Type Ordering Code Frequency Package ICE2AS01 Q67040-S4472 100kHz P-DIP-8-4 ICE2AS01G Q67040-S4473 100kHz P-DSO-8-3 ICE2BS01 Q67040-S4475 67kHz P-DIP-8-4 ICE2BS01G Q67040-S4476 67kHz P-DSO-8-3 Version 2.0 3 1 Feb 2002 ICE2AS01/G ICE2BS01/G Table of Contents Page 1 1.1 1.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Pin Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Pin Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 2 Pin Configuration and Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 3 Representative Blockdiagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 4 4.1 4.2 4.2.1 4.2.2 4.3 4.4 4.4.1 4.4.2 4.5 4.5.1 4.5.2 4.6 4.7 4.8 4.8.1 4.8.2 4.8.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Power Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Improved Current Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 PWM-OP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 PWM-Comparator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 Soft-Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Oscillator and Frequency Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Frequency Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Current Limiting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Leading Edge Blanking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Propagation Delay Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 PWM-Latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Protection Unit (Auto Restart Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Overload & Open loop with normal load . . . . . . . . . . . . . . . . . . . . . . . . .12 Overvoltage due to open loop with no load . . . . . . . . . . . . . . . . . . . . . . .13 Thermal Shut Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 5 5.1 5.2 5.3 5.3.1 5.3.2 5.3.3 5.3.4 5.3.5 5.3.6 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Supply Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Internal Voltage Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Control Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Protection Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 Current Limiting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 Driver Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 6 Typical Performance Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . .19 7 Outline Dimension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 Version 2.0 4 1 Feb 2002 ICE2AS01/G ICE2BS01/G 1 Pin Configuration and Functionality 1.1 Pin Configuration 1.2 SoftS (Soft Start & Auto Restart Control) This pin combines the function of Soft Start in case of Start Up and Auto Restart Mode and the controlling of the Auto Restart Mode in case of an error detection. Pin Symbol Function 1 N.C. Not connected 2 SoftS Soft Start & Auto Restart Control 3 FB Regulation Fedback 4 Isense Controller Current Sense Input 5 Gate Driver Output 6 VCC Controller Supply Voltage 7 GND Controller Ground 8 N.C. Not connected FB (Feedback) The information about the regulation is provided by the FB Pin to the internal Protection Unit and to the internal PWM-Comparator to control the duty cycle. Isense (Current Sense) The Current Sense pin senses the voltage developed on the series resistor inserted in the source of the external Power Switch. When Isense reaches the internal threshold of the Current Limit Comparator, the Driver output is disabled. By this mean the Over Current Detection is realized. Furthermore the current information is provided for the PWM-Comparator to realize the Current Mode. Package P-DIP-8-4 G-Package P-DSO-8-3 N.C. 1 8 N.C. SoftS 2 7 GND FB Isense Figure 1 Version 2.0 Pin Functionality 3 6 4 5 Gate (Driver Output) The current and slew rate capability of this pin are suited to drive Power MOSFETs. VCC (Power supply) This pin is the positiv supply of the IC. The operating range is between 8.5V and 21V. To provide overvoltage protection the driver gets disabled when the voltage becomes higher than 16.5V during Start up Phase. VCC Gate GND (Ground) This pin is the ground of the primary side of the SMPS. Pin Configuration (top view) 5 1 Feb 2002 Version 2.0 FB CSoft-Start T1 6 Thermal Shutdown C3 C4 C2 Protection Unit Tj >140°C 4.8V 5.3V 4.0V C1 G2 G1 GND ICE2AS01 / ICE2BS01 RFB 6.5V 5.6V RSoft-Start 6.5V 16.5V VCC RStart-up fnorm fstandby Q Q fosc UFB Error-Latch R S Power-Up Reset Standby Unit G3 13.5V Power-Down Reset 8.5V x3.65 C5 PWM Comparator Soft-Start Comparator 6.5V 5.3V 4.8V 4.0V Current-Limit Comparator G4 Current Limiting Vcsth Q Q Gate Driver D1 10kΩ 100kHz 21.5kHz 67kHz Frequency in Standby Mode fstandby: 20kHz ICE2AS01/SO1G Leading Edge Blanking 200ns ICE2BS01/SO1G R S PWM-Latch 0.72 Propagation-Delay Compensation Clock Duty Cycle max Oscillator Frequency in Normal Mode fnorm: Improved Current Mode PWM OP 0.8V 0.3V Soft Start Voltage Reference Internal Bias Power Management Undervoltage Lockout Spike Blanking 5µs CVCC CLine Isense Gate Snubber Optocoupler RSense 2 SoftS 85 ... 270 VAC + Converter DC Output VOUT - ICE2AS01/G ICE2BS01/G Representative Blockdiagram Representative Blockdiagram Figure 2 1 Feb 2002 ICE2AS01/G ICE2BS01/G Functional Description 3 Functional Description 3.1 Power Management 3.2 M ain L in e (1 00 V -3 80 V ) Improved Current Mode S o ft-S ta rt C o m p a ra to r R S tart-U p P rim ary W in ding P W M -L a tch FB C VC C R Q D rive r VCC P W M C o m p a ra to r Pow er M anagem ent S U n de rvolta g e Q In te rn a l L o ckou t B ias 0 .8V 1 3 .5V 8 .5 V P o w er-D ow n 6.5 V R e set 5.3 V V o lta g e PW M OP x3 .6 5 4.8 V R efe ren ce 4.0 V P o w er-U p Ise n se Im proved C urrent M ode R e se t R Q P W M -L atch Figure 4 6 .5 V S R Soft-Sta rt S o ftS Q Current Mode means that the duty cycle is controlled by the slope of the primary current. This is done by comparison the FB signal with the amplified current sense signal. E rro r-L a tch S o ft-S ta rt C om p ara tor C S oft-Start T1 Current Mode E rror-D ete ctio n A m p lified C u rren t S ig n al Figure 3 Power Management FB The Undervoltage Lockout monitors the external supply voltage VVCC. In case the IC is inactive the current consumption is max. 55µA. When the SMPS is plugged to the main line the current through RStart-up charges the external Capacitor CVCC. When VVCC exceeds the on-threshold VCCon=13.5V the internal bias circuit and the voltage reference are switched on. After it the internal bandgap generates a reference voltage VREF=6.5V to supply the internal circuits. To avoid uncontrolled ringing at switch-on a hysteresis is implemented which means that switch-off is only after active mode when Vcc falls below 8.5V. In case of switch-on a Power Up Reset is done by reseting the internal error-latch in the protection unit. When VVCC falls below the off-threshold VCCoff=8.5V the internal reference is switched off and the Power Down reset let T1 discharging the soft-start capacitor CSoft-Start at pin SoftS. Thus it is ensured that at every switch-on the voltage ramp at pin SoftS starts at zero. Version 2.0 0 .8 V D rive r t T on t Figure 5 Pulse Width Modulation In case the amplified current sense signal exceeds the FB signal the on-time Ton of the driver is finished by reseting the PWM-Latch (see Figure 5). 7 1 Feb 2002 ICE2AS01/G ICE2BS01/G Functional Description The primary current is sensed by the series resistor RSense inserted in the source of the external Power Switch. By means of Current Mode the regulation of the secondary voltage is insensitive on line variations. Line variation causes varition of the increasing current slope which controls the duty cycle. The external RSense allows an individual adjustment of the maximum source current of the external Power Switch. V OSC m a x. D u ty C yc le V olta ge R a m p t S oft-S tart C o m p ara to r P W M C o m pa ra to r 0 .8 V FB FB 0 .3 V P W M -La tch O s cilla to r G a te D rive r 0.3V t C5 G a te D rive r V O SC 0.8V 1 0 kΩ x3 .6 5 R1 T2 C1 V1 2 0p F t PW M OP Figure 7 3.2.1 V oltage Ram p Figure 6 PWM-OP The input of the PWM-OP is applied over the internal leading edge blanking to the external sense resistor RSense connected to pin ISense. RSense converts the source current into a sense voltage. The sense voltage is amplified with a gain of 3.65 by PWM OP. The output of the PWM-OP is connected to the voltage source V1. The voltage ramp with the superimposed amplified current singal is fed into the positive inputs of the PWMComparator, C5 and the Soft-Start-Comparator. Improved Current Mode To improve the Current Mode during light load conditions the amplified current ramp of the PWM-OP is superimposed on a voltage ramp, which is built by the switch T2, the voltage source V1 and the 1st order low pass filter composed of R1 and C1 (see Figure 6, Figure 7). Every time the oscillator shuts down for max. duty cycle limitation the switch T2 is closed by VOSC. When the oscillator triggers the Gate Driver T2 is opened so that the voltage ramp can start (see Figure 7). In case of light load the amplified current ramp is to small to ensure a stable regulation. In that case the Voltage Ramp is a well defined signal for the comparison with the FB-signal. The duty cycle is then controlled by the slope of the Voltage Ramp. By means of the C5 Comparator the Gate Driver is switched-off until the voltage ramp exceeds 0.3V. It allows the duty cycle to be reduced continously till 0% by decreasing VFB below that threshold. Version 2.0 Light Load Conditions 3.2.2 PWM-Comparator The PWM-Comparator compares the sensed current signal of the external Power Switch with the feedback signal VFB (see Figure 8). VFB is created by an external optocoupler or external transistor in combination with the internal pullup resistor RFB and provides the load information of the feedback circuitry. When the amplified current signal of the external Power Switch exceeds the signal VFB the PWM-Comparator switches off the Gate Driver. 8 1 Feb 2002 ICE2AS01/G ICE2BS01/G Functional Description pullup resistor RSoft-Start. The Soft-Start-Comparator compares the voltage at pin SoftS at the negative input with the ramp signal of the PWM-OP at the positive input. When Soft-Start voltage VSoftS is less than Feedback voltage VFB the Soft-Start-Comparator limits the pulse width by reseting the PWM-Latch (see Figure 9). In addition to Start-Up, Soft-Start is also activated at each restart attempt during Auto Restart. By means of the above mentioned CSoft-Start the Soft-Start can be defined by the user. The Soft-Start is finished when VSoftS exceeds 5.3V. At that time the Protection Unit is activated by Comparator C4 and senses the FB by Comparator C3 wether the voltage is below 4.8V which means that the voltage on the secondary side of the SMPS is settled. The internal Zener Diode at SoftS with breaktrough voltage of 5.6V is to prevent the internal circuit from saturation (see Figure 10). 6 .5 V S o ft-S ta rt C o m p ara to r R FB FB P W M -L atch P W M C o m p a rato r 0 .8 V O p to co u p le r PW M OP Ise n se 6 .5 V x3 .65 R S o ft-S ta rt Im proved Current M ode 3.3 E rro r-L a tc h S o ftS 6 .5 V 5 .3 V Figure 8 P o w e r-U p R e s e t 5 .6 V C4 G2 R Q S Q R Q PWM Controlling 4 .8 V R FB Soft-Start FB C3 G a te D riv e r C lo c k V S oftS S Q P W M -L a tc h Figure 10 5 .6 V 5 .3 V The Start-Up time TStart-Up within the converter output voltage VOUT is settled must be shorter than the SoftStart Phase TSoft-Start (see Figure 11). T S oft-S tart G a te D rive r Activation of Protection Unit C Soft − Start = t T Soft − Start R Soft − Start × 1, 69 By means of Soft-Start there is an effective minimization of current and voltage stresses on the external Power Switch, the clamp circuit and the output overshoot and prevents saturation of the transformer during Start-Up. t Figure 9 Soft-Start Phase The Soft-Start is realized by the internal pullup resistor RSoft-Start and the external Capacitor CSoft-Start (see Figure 2). The Soft-Start voltage VSoftS is generated by charging the external capacitor CSoft-Start by the internal Version 2.0 9 1 Feb 2002 ICE2AS01/G ICE2BS01/G Functional Description V S o ftS kHz fnorm f OSC 5 .3 V T S oft-S ta rt V FB fstandby t 1,0 1,1 1,2 1,3 1,4 1,6 1,7 1,8 1,9 2 V VFB 4 .8 V ICE2BS01 V OUT t V O UT 67kHz 100kHz fstandby: 20kHz 21.5kHz 3.5 T S ta rt-U p Start Up Phase 3.4 Oscillator and Frequency Reduction 3.4.1 Oscillator The oscillator generates a frequency fswitch = 100kHz. A resistor, a capacitor and a current source and current sink which determine the frequency are integrated. The charging and discharging current of the implemented oscillator capacitor are internally trimmed, in order to achieve a very accurate switching frequency. The ratio of controlled charge to discharge current is adjusted to reach a max. duty cycle limitation of Dmax=0.72. Current Limiting 3.5.1 Leading Edge Blanking V S en s e Frequency Reduction V c s th The frequency of the oscillator is depending on the voltage at pin FB. The dependence is shown in Figure 12. This feature allows a power supply to operate at lower frequency at light loads thus lowering the switching losses while maintaining good cross regulation performance and low output ripple. In case of low power the power consumption of the whole SMPS can now be reduced very effective. The minimal reachable frequency is limited to 20kHz / 21.5 kHz to avoid audible noise in any case. Version 2.0 Frequency Dependence There is a cycle by cycle current limiting realised by the Current-Limit Comparator to provide an overcurrent detection. The source current of the external Power Switch is sensed via an external sense resistor RSense . By means of RSense the source current is transformed to a sense voltage VSense. When the voltage VSense exceeds the internal threshold voltage Vcsth the Current-Limit-Comparator immediately turns off the gate drive. To prevent the Current Limiting from distortions caused by leading edge spikes a Leading Edge Blanking is integrated at the Current Sense. Furthermore a Propagation Delay Compensation is added to support the immedeate shut down of the Power Switch in case of overcurrent. t Figure 11 ICE2AS01 fnorm: Figure 12 3.4.2 1,5 t L E B = 22 0 ns t Figure 13 Leading Edge Blanking Each time when the external Power Switch is switched on a leading spike is generated due to the primary-side capacitances and secondary-side rectifier reverse 10 1 Feb 2002 ICE2AS01/G ICE2BS01/G Functional Description recovery time. To avoid a premature termination of the switching pulse this spike is blanked out with a time constant of tLEB = 220ns. During that time the output of the Current-Limit Comparator cannot switch off the gate drive. 3.5.2 VOSC max. Duty Cycle Propagation Delay Compensation off time In case of overcurrent detection the shut down of the external Power Switch is delayed due to the propagation delay of the circuit. This delay causes an overshoot of the peak current Ipeak which depends on the ratio of dI/dt of the peak current (see Figure 14). . S ig n a l2 VSense Vcsth S ig n a l1 t P ro pa ga tion D e la y I S e ns e I O v ers h oo t2 I p ea k 2 I p ea k 1 I L im it t Propagation Delay Signal1 Signal2 t Figure 15 I O v e rs ho ot1 Dynamic Voltage Threshold Vcsth with compensation without compensation V t 1,25 Current Limiting 1,2 VSense Figure 14 1,3 The overshoot of Signal2 is bigger than of Signal1 due to the steeper rising waveform. A propagation delay compensation is integrated to bound the overshoot dependent on dI/dt of the rising primary current. That means the propagation delay time between exceeding the current sense threshold Vcsth and the switch off of the external Power Switch is compensated over temperature within a range of at least . 0 ≤ RSense dI × peak dt ≤ 1 1,1 1,05 1 0,95 0,9 0 0,2 0,4 0,6 0,8 1 1,2 1,4 dVSense dt Figure 16 dVSense dt 3.6 1,6 1,8 2 V µs Overcurrent Shutdown PWM-Latch The oscillator clock output applies a set pulse to the PWM-Latch when initiating the external Power Switch conduction. After setting the PWM-Latch can be reset by the PWM-OP, the Soft-Start-Comparator, the Current-Limit-Comparator, Comparator C3 or the Error-Latch of the Protection Unit. In case of reseting the driver is shut down immediately. So current limiting is now capable in a very accurate way (see Figure 16). E.g. Ipeak = 0.5A with RSense = 2 . Without propagation delay compensation the current sense threshold is set to a static voltage level Vcsth=1V. A current ramp of dI/dt = 0.4A/µs, that means dVSense/dt = 0.8V/µs, and a propagation delay time of i.e. tPropagation Delay =180ns leads then to an Ipeak overshoot of 12%. By means of propagation delay compensation the overshoot is only about 2% (see Figure 15). The propagation delay compensation is done by means of a dynamic threshold voltage Vcsth (see Figure 15). In case of a steeper slope the switch off of the driver is earlier to compensate the delay. Version 2.0 1,15 3.7 Driver The driver is a fast totem pole gate drive, which is designed to avoid cross conduction currents and which is equipped with a Zener diode Z1 (see Figure 17) in order to improve the control of the gate attached power 11 1 Feb 2002 ICE2AS01/G ICE2BS01/G Functional Description failure modes are latched by an Error-Latch. Additional thermal shutdown is latched by the Error-Latch. In case of those failure modes the Error-Latch is set after a blanking time of 5µs and the external Power Switch is shut down. That blanking prevents the Error-Latch from distortions caused by spikes during operation mode. transistors as well as to protect them against undesirable gate overvoltages. VCC P W M -La tch 3.8.1 1 Overload & Open loop with normal load G a te Z1 O verload & O pen loop/norm al load FB 5µ s B la nking 4 .8 V F ailure D e tectio n Figure 17 Gate Driver t S oftS At voltages below the undervoltage lockout threshold VVCCoff the gate drive is active low. The driver-stage is optimized to minimize EMI and to provide high circuit efficiency. This is done by reducing the switch on slope when reaching the external Power Switch threshold. This is achieved by a slope control of the rising edge at the driver’s output (see Figure 18). 5 .3 V S oft-S tart P h ase D river t T B u rs t1 T R e s tart V G a te ca . t = 1 3 0 n s C L o ad = 1n F t VC C 5V 1 3 .5 V 8 .5V t Figure 18 Gate Rising Slope t Figure 19 Thus the leading switch on spike is minimized. When the external Power Switch is switched off, the falling shape of the driver is slowed down when reaching 2V to prevent an overshoot below ground. Furthermore the driver circuit is designed to eliminate cross conduction of the output stage. 3.8 Auto Restart Mode Figure 19 shows the Auto Restart Mode in case of overload or open loop with normal load. The detection of open loop or overload is provided by the Comparator C3, C4 and the AND-gate G2 (see Figure20). Protection Unit (Auto Restart Mode) An overload, open loop and overvoltage detection is integrated within the Protection Unit. These three Version 2.0 12 1 Feb 2002 ICE2AS01/G ICE2BS01/G Functional Description 3.8.2 Overvoltage due to open loop with no load 6.5 V P o w e r U p R e se t S o ftS R S oft-S tart O pen loop & no load conditio n FB 5 µs B la n kin g 4 .8V C S oft-S tart C4 5 .3 V E rro r-L a tch F ailure D ete ction G2 T1 4 .8V C3 FB S o ftS 5 .3V R FB 4 .0V 6 .5 V Figure 20 t S o ft-S ta rt P ha se O v erv olta g e D e te ction P ha se FB-Detection D rive r T R es ta rt The detection is activated by C4 when the voltage at pin SoftS exceeds 5.3V. Till this time the IC operates in the Soft-Start Phase. After this phase the comparator C3 can set the Error-Latch in case of open loop or overload which leads the feedback voltage VFB to exceed the threshold of 4.8V. After latching VCC decreases till 8.5V and inactivates the IC. At this time the external Soft-Start capacitor is discharged by the internal transistor T1 due to Power Down Reset. When the IC is inactive VCC increases till VCCon = 13.5V by charging the Capacitor CVCC by means of the Start-Up Resistor RStart-Up. Then the Error-Latch is reset by Power Up Reset and the external Soft-Start capacitor CSoft-Start is charged by the internal pullup resistor RSoftStart . During the Soft-Start Phase which ends when the voltage at pin SoftS exceeds 5.3V the detection of overload and open loop by C3 and G2 is inactive. In this way the Start Up Phase is not detected as an overload. But the Soft-Start Phase must be finished within the Start Up Phase to force the voltage at pin FB below the failure detection threshold of 4.8V. Version 2.0 t T B urs t2 O ve rvo ltag e D ete ctio n t VCC 1 6.5 V 1 3.5 V 8.5 V t Figure 21 Auto Restart Mode Figure 21 shows the Auto Restart Mode for open loop and no load condition. In case of this failure mode the converter output voltage increases and also VCC. An additional protection by the comparators C1, C2 and the AND-gate G1 is implemented to consider this failure mode (see Figure 22). 13 1 Feb 2002 ICE2AS01/G ICE2BS01/G Functional Description VCC 6 .5 V C1 1 6 .5 V E rro r L a tch G1 R S o ft-S ta rt 4 .0 V C2 S o ftS C S o ft-S ta rt T1 Figure 22 P o w e r U p R e se t Overvoltage Detection The overvoltage detection is provided by Comparator C1 only in the first time during the Auto Restart Mode till the Soft-Start voltage exceeds the threshold of the Comparator C2 at 4.0V and the voltage at pin FB is above 4.8V. When VCC exceeds 16.5V during the overvoltage detection phase C1 can set the Error-Latch and the Burst Phase during Auto Restart Mode is finished earlier. In that case TBurst2 is shorter than TSoftStart . By means of C2 the normal operation mode is prevented from overvoltage detection due to varying of VCC concerning the regulation of the converter output. When the voltage VSoftS is above 4.0V the overvoltage detection by C1 is deactivated. 3.8.3 Thermal Shut Down Thermal Shut Down is latched by the Error-Latch when junction temperature Tj of the pwm controller is exceeding an internal threshold of 140°C. In that case the IC switches in Auto Restart Mode. Note: All the values which are mentioned in the functional description are typical. Please refer to Electrical Characteristics for min/max limit values. Version 2.0 14 1 Feb 2002 ICE2AS01/G ICE2BS01/G Electrical Characteristics 4 Electrical Characteristics 4.1 Absolute Maximum Ratings Note: Absolute maximum ratings are defined as ratings, which when being exceeded may lead to destruction of the integrated circuit. For the same reason make sure, that any capacitor that will be connected to pin 6 (VCC) is discharged before assembling the application circuit. Parameter Symbol Limit Values min. max. Unit Remarks VCC Supply Voltage VCC -0.3 22 V FB Voltage VFB -0.3 6.5 V SoftS Voltage VSoftS -0.3 6.5 V ISense ISense -0.3 3 V Junction Temperature Tj -40 150 °C Storage Temperature TS -50 150 °C Thermal Resistance Junction-Ambient RthJA - 90 K/W P-DIP-8-4 Thermal Resistance Junction-Ambient RthJA - 185 K/W P-DSO-8-3 ESD Capability1) VESD - 2 kV Human Body Model 1) Controller & CoolMOS Equivalent to discharging a 100pF capacitor through a 1.5 kΩ series resistor 4.2 Note: Operating Range Within the operating range the IC operates as described in the functional description. Parameter Symbol Limit Values min. max. Unit VCC Supply Voltage VCC VCCoff 21 V Junction Temperature of Controller TJCon -25 130 °C Version 2.0 15 Remarks limited due to thermal shut down of controller 1 Feb 2002 ICE2AS01/G ICE2BS01/G Electrical Characteristics 4.3 Note: 4.3.1 Characteristics The electrical characteristics involve the spread of values guaranteed within the specified supply voltage and junction temperature range TJ from – 25 °C to 125 °C.Typical values represent the median values, which are related to 25°C. If not otherwise stated, a supply voltage of VCC = 15 V is assumed. Supply Section Parameter Symbol Limit Values min. typ. max. Unit Test Condition Start Up Current IVCC1 - 27 55 µA VCC=VCCon -0.1V Supply Current with Inactiv Gate IVCC2 - 5.3 7 mA VSoftS = 0 IFB = 0 Supply Current with Activ Gate ICE2AS01/G IVCC3 - 6.5 8 mA VSoftS = 5V IFB = 0 CGate = 1nF Supply Current with Activ Gate ICE2BS01/G IVCC3 - 6 7.5 mA VSoftS = 5V IFB = 0 CGate = 1nF VCC Turn-On Threshold VCC Turn-Off Threshold VCC Turn-On/Off Hysteresis VCCon VCCoff VCCHY 13 4.5 13.5 8.5 5 14 5.5 V V V 4.3.2 Internal Voltage Reference Parameter Trimmed Reference Voltage 4.3.3 Symbol VREF Limit Values min. typ. max. 6.37 6.50 6.63 Unit Test Condition V measured at pin FB Unit Test Condition Control Section Parameter Symbol Limit Values min. typ. max. Oscillator Frequency ICE2AS01/G fOSC1 93 100 107 kHz VFB = 4V Oscillator Frequency ICE2BS01/G fOSC3 62 67 72 kHz VFB = 4V Reduced Osc. Frequency ICE2AS01/G fOSC2 - 21.5 - kHz VFB = 1V Reduced Osc. Frequency ICE2AS01/G fOSC4 - 20 - kHz VFB = 1V Version 2.0 16 1 Feb 2002 ICE2AS01/G ICE2BS01/G Electrical Characteristics Frequency Ratio fosc1/fosc2 ICE2AS01/G 4.5 4.65 4.9 Frequency Ratio fosc3/fosc4 ICE2BS01/G 3.18 3.35 3.53 Max Duty Cycle Dmax 0.67 0.72 0.77 Min Duty Cycle Dmin 0 - - PWM-OP Gain AV 3.45 3.65 3.85 Max. Level of Voltage Ramp VMax-Ramp - 0.85 - V VFB Operating Range Min Level VFBmin 0.3 - - V VFB Operating Range Max level VFBmax - - 4.6 V Feedback Resistance RFB 3.0 3.7 4.9 kΩ Soft-Start Resistance RSoft-Start 42 50 62 kΩ 4.3.4 VFB < 0V Protection Unit Parameter Symbol Limit Values min. typ. max. Unit Test Condition Over Load & Open Loop Detection Limit VFB2 4.65 4.8 4.95 V VSoftS > 5.5V Activation Limit of Overload & Open Loop Detection VSoftS1 5.15 5.3 5.46 V VFB > 5V Deactivation Limit of Overvoltage Detection VSoftS2 3.88 4.0 4.12 V VFB > 5V VCC > 17.5V Overvoltage Detection Limit VVCC1 16 16.5 17.2 V VSoftS < 3.8V VFB > 5V Latched Thermal Shutdown TjSD 130 140 150 °C guaranteed by design Spike Blanking tSpike - 5 - µs 4.3.5 Current Limiting Parameter Symbol Limit Values min. typ. max. Unit Test Condition dVsense / dt = 0.6V/µs Peak Current Limitation (incl. Propagation Delay Time) (see Figure 7) Vcsth 0.95 1.00 1.05 V Leading Edge Blanking tLEB - 220 - ns Version 2.0 17 1 Feb 2002 ICE2AS01/G ICE2BS01/G Electrical Characteristics 4.3.6 Driver Section Parameter GATE Low Voltage GATE High Voltage Symbol VGATE VGATE Limit Values Unit Test Condition min. typ. max. - 0.95 1.2 V VVCC = 5 V IGate = 5 mA - 1.0 1.5 V VVCC = 5 V IGate = 20 mA - 0.88 - V IGate = 0 A - 1.6 2.2 V IGate = 50 mA -0.2 0.2 - V IGate = -50 mA - 11.5 - V VVCC = 20V CL = 4.7nF - 10 - V VVCC = 11V CL = 4.7nF - 7.5 - V VVCC = VVCCoff + 0.2V CL = 4.7nF GATE Rise Time tr - 160 - ns VGate = 2V ...9V1) CL = 4.7nF GATE Fall Time tf - 65 - ns VGate = 9V ...2V1) CL = 4.7nF GATE Current, Peak, Rising Edge IGATE -0.5 - - A CL = 4.7nF2) GATE Current, Peak, Falling Edge IGATE - - 0.7 A CL = 4.7nF2) 1) Transient reference value 2) Design characteristics (not meant for production testing) Version 2.0 18 1 Feb 2002 ICE2AS01/G ICE2BS01/G Typical Performance Characteristics Typical Performance Characteristics 40 VCC Turn-On Threshold V CCon [V] 13,58 36 34 32 PI-001-190101 Start Up Current I VCC1 [µA] 38 30 28 26 24 22 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 13,56 13,54 13,52 13,50 13,48 13,46 13,44 13,42 -25 -15 105 115 125 PI-004-190101 5 -5 5 Start Up Current IVCC1 vs. Tj Figure 26 VCC Turn-Off Threshold V VCCoff [V] 5,7 5,4 5,1 4,8 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 65 75 85 95 105 115 125 8,64 8,61 8,58 8,55 8,52 8,49 8,46 8,43 8,40 -25 -15 Figure 27 -5 5 ICE2ASO1 ICE2ASO1G 6,6 6,4 PI-002-190101 6,2 6,0 5,8 ICE2BSO1 ICE2BSO1G 5,6 5,4 5,2 5,0 -25 -15 -5 5 25 35 45 55 65 75 85 95 105 115 125 15 25 35 45 55 65 75 85 95 105 115 125 VCC Turn-Off Threshold VVCCoff vs. Tj 5,10 5,07 5,04 5,01 4,98 4,95 4,92 4,89 4,86 4,83 -25 -15 Junction Temperature [°C] -5 5 15 25 35 45 55 65 75 85 95 105 115 125 Junction Temperature [°C] Figure 28 Supply Current IVCC3 vs. Tj Version 2.0 15 PI-006-190101 VCC Turn-On/Off Hysteresis V CCHY [V] Supply Current IVCC2 vs. Tj 6,8 Supply Current I VCC3 [mA] 55 Junction Temperature [°C] 7,0 Figure 25 45 VCC Turn-On Threshold VVCCon vs. Tj Junction Temperature [°C] Figure 24 35 8,67 PI-003-190101 Supply Current IVCC2 [mA] 6,0 4,5 -25 -15 25 PI-005-190101 Figure 23 15 Junction Temperature [°C] Junction Temperature [°C] 19 VCC Turn-On/Off HysteresisVVCCHY vs. Tj 1 Feb 2002 ICE2AS01/G ICE2BS01/G Typical Performance Characteristics 6,53 6,52 6,51 6,50 6,49 6,48 6,47 6,46 6,45 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 21,8 21,7 21,6 ICE2ASO1 ICE2ASO1G 21,5 21,4 PI-009-190101 Reduced Osc. Frequency OSC2 f [kHz] 6,54 PI-007-190101 Trimmed Reference Voltage V REF [V] 6,55 21,3 21,2 21,1 21,0 20,9 20,8 -25 -15 -5 Trimmed Reference VREF vs. Tj Figure 32 [kHz] OSC4 101,5 ICE2ASO1 ICE2ASO1G Reduced Osc. Frequency f 100,5 100,0 PI-008-190101 Oscillator Frequency OSC1 f [kHz] 102,0 101,0 99,5 99,0 98,5 98,0 97,5 97,0 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 20,4 95 105 115 125 ICE2BSO1 ICE2BSO1G 19,8 19,6 19,4 19,2 19,0 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 67,5 66,0 65,5 65,0 64,5 Reduced Osc. Frequency fOSC4 vs. Tj 4,66 4,64 ICE2ASO1 ICE2ASO1G 4,62 PI-010-190101 Frequency Ratio fOSC1/fOSC2 ICE2BSO1 ICE2BSO1G PI-008a-190101 Oscillator Frequency f OSC3 [kHz] 68,5 4,60 4,58 4,56 4,54 4,52 4,50 -25 -15 -5 15 25 35 45 55 65 75 85 95 105 115 125 Junction Temperature [°C] 5 15 25 35 45 55 65 75 85 95 105 115 125 Junction Temperature [°C] Oscillator Frequency fOSC3 vs. Tj Version 2.0 85 20,0 4,68 Figure 31 75 20,2 Figure 33 69,0 5 65 20,6 4,70 64,0 -25 -15 -5 55 20,8 69,5 66,5 45 21,0 70,0 67,0 35 Junction Temperature [°C] Oscillator Frequency fOSC1 vs. Tj 68,0 25 Reduced Osc. Frequency fOSC2 vs. Tj Junction Temperature [°C] Figure 30 15 PI-009a-190101 Figure 29 5 Junction Temperature [°C] Junction Temperature [°C] Figure 34 20 Frequency Ratio fOSC1 / fOSC2 vs. Tj 1 Feb 2002 ICE2AS01/G ICE2BS01/G Typical Performance Characteristics 4,00 3,41 3,39 3,37 PI-010a-190101 Frequency Ratio fOSC3/fOSC4 3,43 ICE2BSO1 ICE2BSO1G 3,35 3,33 3,31 3,29 3,27 3,25 -25 -15 -5 5 15 25 35 45 55 65 75 85 3,95 3,90 3,85 3,80 3,75 3,70 3,65 3,60 3,55 3,50 -25 -15 95 105 115 125 PI-013-190101 Feedback Resistance R FB [kOhm] 3,45 -5 5 Junction Temperature [°C] Frequency Ratio fOSC3 / fOSC4 vs. Tj Figure 38 Soft-Start Resistance R Soft-Start [kOhm] 0,730 0,728 0,724 0,722 PI-011-190101 Max. Duty Cycle 0,726 0,720 0,718 0,716 0,714 0,712 0,710 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 65 75 85 95 105 115 125 54 52 50 48 46 44 42 40 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 Junction Temperature [°C] Figure 39 4,84 3,68 4,83 Detection Limit V FB2 [V] 4,85 3,67 3,66 3,65 3,64 3,63 3,62 3,61 Soft-Start Resistance RSoft-Start vs. Tj 4,82 4,81 PI-015-190101 Max. Duty Cycle vs. Tj PI-012-190101 PWM-OP Gain AV 55 56 3,69 4,80 4,79 4,78 4,77 4,76 -5 5 15 25 35 45 55 65 75 85 4,75 -25 -15 95 105 115 125 Junction Temperature [°C] Figure 37 45 58 3,70 3,60 -25 -15 35 Feedback Resistance RFB vs. Tj Junction Temperature [°C] Figure 36 25 PI-014-190101 Figure 35 15 Junction Temperature [°C] 5 15 25 35 45 55 65 75 85 95 105 115 125 Junction Temperature [°C] PWM-OP Gain AV vs. Tj Version 2.0 -5 Figure 40 21 Detection Limit VFB2 vs. Tj 1 Feb 2002 ICE2AS01/G ICE2BS01/G 1,010 5,34 1,008 5,33 5,32 5,31 5,30 5,29 5,28 5,27 5,26 5,25 -25 -15 -5 5 15 25 35 45 55 65 75 85 1,006 1,004 1,002 1,000 0,998 0,996 0,994 0,992 0,990 -25 -15 95 105 115 125 PI-019-190101 Peak Current Limitation V csth [V] 5,35 PI-016-190101 Detection Limit V Soft-Start1 [V] Typical Performance Characteristics -5 5 Junction Temperature [°C] Figure 44 280 4,04 270 Leading Edge Blanking t LEB [ns] 4,05 4,03 4,02 4,01 4,00 3,99 3,98 3,97 3,96 3,95 -25 -15 -5 5 15 25 35 45 55 65 75 45 55 65 75 85 95 105 115 125 85 250 240 230 220 210 200 190 180 -25 -15 95 105 115 125 Peak Current Limitation Vcsth vs. Tj -5 5 15 25 35 45 55 65 75 85 95 105 115 125 Junction Temperature [°C] Detection Limit VSoft-Start2 vs. Tj Figure 45 Leading Edge Blanking VVCC1 vs. Tj 16,80 16,75 16,70 16,65 16,60 16,55 PI-018-190101 Overvoltage Detection Limit V VCC1 [V] 35 260 Junction Temperature [°C] Figure 42 25 PI-020-190101 Detection Limit VSoft-Start1 vs. Tj PI-017-190101 Detection Limit V Soft-Start2 [V] Figure 41 15 Junction Temperature [°C] 16,50 16,45 16,40 16,35 16,30 16,25 16,20 -25 -15 -5 5 15 25 35 45 55 65 75 85 95 105 115 125 Junction Temperature [°C] Figure 43 Overvoltage Detection Limit VVCC1 vs. Tj Version 2.0 22 1 Feb 2002 Preliminary Specification ICE2AS01/G ICE2BS01/G Outline Dimension 6 Outline Dimension P-DSO-8-3 (Plastic Dual Small Outline) Figure 46 P-DIP-8-4 (Plastic Dual In-line Package) Figure 47 Dimensions in mm Version 2.0 23 1 Feb 2002 Total Quality Management Qualität hat für uns eine umfassende Bedeutung. Wir wollen allen Ihren Ansprüchen in der bestmöglichen Weise gerecht werden. Es geht uns also nicht nur um die Produktqualität – unsere Anstrengungen gelten gleichermaßen der Lieferqualität und Logistik, dem Service und Support sowie allen sonstigen Beratungs- und Betreuungsleistungen. Quality takes on an allencompassing significance at Semiconductor Group. For us it means living up to each and every one of your demands in the best possible way. So we are not only concerned with product quality. We direct our efforts equally at quality of supply and logistics, service and support, as well as all the other ways in which we advise and attend to you. Dazu gehört eine bestimmte Geisteshaltung unserer Mitarbeiter. Total Quality im Denken und Handeln gegenüber Kollegen, Lieferanten und Ihnen, unserem Kunden. Unsere Leitlinie ist jede Aufgabe mit „Null Fehlern“ zu lösen – in offener Sichtweise auch über den eigenen Arbeitsplatz hinaus – und uns ständig zu verbessern. Part of this is the very special attitude of our staff. Total Quality in thought and deed, towards co-workers, suppliers and you, our customer. Our guideline is “do everything with zero defects”, in an open manner that is demonstrated beyond your immediate workplace, and to constantly improve. Unternehmensweit orientieren wir uns dabei auch an „top“ (Time Optimized Processes), um Ihnen durch größere Schnelligkeit den entscheidenden Wettbewerbsvorsprung zu verschaffen. Geben Sie uns die Chance, hohe Leistung durch umfassende Qualität zu beweisen. Wir werden Sie überzeugen. http://www.infineon.com Published by Infineon Technologies AG Throughout the corporation we also think in terms of Time Optimized Processes (top), greater speed on our part to give you that decisive competitive edge. Give us the chance to prove the best of performance through the best of quality – you will be convinced.