L6566BH STMicroelectronics, L6566BH Datasheet

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... BURST-MODE + MODE SELECTION & TURN-ON LOGIC TIME ZERO CURRENT OUT OVPL - DETECTOR + OVP OVERVOLTAGE LATCH PROTECTION IC_LATCH - AC_FAIL DISABLE 0.450V + UVLO 0.485V Doc ID 16610 Rev 1 L6566BH SO16N VFF 6.4V - OVPL OVP LEB 7 1 OCP V CC Hiccup-mode 14V OCP logic ...

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... Latched disable function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 5.10 Soft-start and delayed latched shutdown upon overcurrent . . . . . . . . . . . 31 5.11 OVP block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 5.12 Brownout protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 5.13 Slope compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 5.14 Summary of L6566BH power management functions . . . . . . . . . . . . . . . 39 6 Application examples and ideas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 8 Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 2/48 ...

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... Table 1. Pin functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Table 2. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Table 3. Thermal data Table 4. Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Table 5. L6566BH light load management features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Table 6. L6566BH protections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Table 7. External circuits that determine IC behavior upon OVP and OCP . . . . . . . . . . . . . . . . . . . 42 Table 8. SO16N mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Table 9. Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Table 10. ...

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... Addition of an offset to the current sense lowers the burst-mode operation threshold . . . . 23 Figure 13. Adaptive UVLO block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Figure 14. Possible feedback configurations that can be used with the L6566BH . . . . . . . . . . . . . . . 24 Figure 15. Externally controlled burst-mode operation by driving pin COMP: timing diagram Figure 16. Typical power capability change vs input voltage in QR flyback converters . . . . . . . . . . . 26 Figure 17. Left: overcurrent setpoint vs VFF voltage ...

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... L6566BH 1 Description The L6566BH is an extremely versatile current-mode primary controller ICs, specifically designed for high-performance offline flyback converters running off rectified 3-phase input line also suited for single-stage single-switch input-current-shaping converters (single- stage PFC) for applications supposed to comply with EN61000-3-2 or JEITA-MITI regulations ...

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... Description Figure 2. Typical system block diagram Rectified & Filtered Mains Voltage 6/48 FLYBACK DC-DC CONVERTER L6566BH Doc ID 16610 Rev 1 L6566BH V outdc ...

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... L6566BH 2 Pin settings 2.1 Connections Figure 3. Pin connection (through top view) 2.2 Pin description Table 1. Pin functions N° Pin High-voltage start-up. The pin, able to withstand 800 tied directly to the rectified mains voltage internal current source charges the capacitor connected between Vcc pin (5) and GND pin (3) until the voltage on the Vcc pin reaches the turn-on threshold, then it is shut down ...

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... GND (3), is recommended to ensure the stability of 10 VREF the generator and to prevent noise from affecting the reference. This reference is internally monitored by a separate auxiliary reference and any failure or drift will cause the IC to latch off. 8/48 Function Doc ID 16610 Rev 1 L6566BH ...

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... OSC the oscillator frequency that defines the maximum allowed switching frequency of the L6566BH, if working in QR mode, or the operating switching frequency if working in FF mode. Soft-start current source. At start-up a capacitor Css between this pin and GND (pin 3) is charged with an internal current generator. During the ramp, the internal ...

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... IC supply voltage (Icc = 20 mA) 6 Voltage range Maximum pin voltage (Ipin ≤ 1 mA) Zero-current detector max. current Voltage range Voltage range Power dissipation @ °C A Storage temperature Junction operating temperature range Parameter Doc ID 16610 Rev 1 L6566BH Value Unit -0.3 to 800 V Self-limited Self-limited -0 -0 Self-limited ± ...

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... L6566BH 4 Electrical characteristics (T = -25 to 125° unless otherwise specified). Table 4. Electrical characteristics Symbol Parameter Supply voltage Vcc Operating range after turn-on Vcc Turn-on threshold On Vcc Turn-off threshold Off Hys Hysteresis V Zener voltage Z Supply current I Start-up current start-up I Quiescent current q Icc Operating supply current ...

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... V ZCDth -0 3.15 6.4 0.4 0.04 150 250 300 100 = 0 V 0.92 1 1.08 VFF = 1.5 V 0.45 0.5 0.55 VFF = 3 VFF 1.4 1.5 5.7 L6566BH Unit 0 kHz µA 3 µ 3 V/V V/V -1 µ 0.1 1 ...

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... L6566BH Table 4. Electrical characteristics (continued) Symbol Parameter V Lower clamp voltage COMPLO V Linear dynamics upper limit COMPSH I Max. source current COMP R Dynamic resistance COMP V Burst-mode threshold COMPBM Hys Burst-mode hysteresis I Lower clamp capability CLAMPL V Disable threshold COMPOFF Level for lower UVLO off ...

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... V COMP COMPHi COMP COMPHi mA, Vcc = 12 V GDsource I = 100 mA GDsink mA; Vcc = 20 V GDsource Vcc = ccon sink ( ) = − − COMP FF Doc ID 16610 Rev 1 L6566BH Min. Typ. Max. Unit 1.5 V 0.5 V 150 µ 1 µA 3.5 5 6.5 3.5 5 6.5 µ 4. ...

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... Valley-skipping mode at medium/ light load. The externally programmable oscillator of the L6566BH, synchronized to MOSFET’s turn-on, enables the designer to define the maximum operating frequency of the converter. As the load is reduced MOSFET’s turn- on will not any more occur on the first valley but on the second one, the third one and so on ...

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... Burst-mode with no or very light load. This kind of operation is activated in the same way and results in the same behavior as previously described for QR operation. The L6566BH is specifically designed for applications with no PFC front-end; pin 6 (FMOD) features an auxiliary oscillator that can modulate the switching frequency (when FF operation is selected) in order to mitigate EMI emissions by a spread-spectrum action ...

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... L6566BH With reference to the timing diagram of the voltage on the bulk capacitor (Vin) builds up and, at about 80 V, the HV generator is enabled to operate (HV_EN is pulled high) so that it draws about 1 mA. This current, minus the device’s consumption, charges the bypass capacitor connected from pin Vcc (5) to ground and makes its voltage rise almost linearly ...

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... COMP 9 blanking START BLANKING 5.7V TIME TURN-ON - MONO LOGIC STABLE + 100 OSCILLATOR Strobe Res et + FAULT 4:1 S/H Counter - 5V Doc ID 16610 Rev 1 T rep rep VFF 15 line FFWD PWM DRIVER S AUXILIARY OSCILLATOR 6 13 FMOD OSC R MOD MOD L6566BH +Vin Q Rs ...

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... This feature is typically used to detect transformer demagnetization for QR operation, where the signal for the ZCD input is obtained from the transformer’s auxiliary winding used also to supply the L6566BH. The triggering block is blanked for T turn-off to prevent any negative-going edge that follows leakage inductance demagnetization from triggering the ZCD circuit erroneously ...

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... BLANK T ≤ − BLANK osc . As a consequence, the maximum switching frequency will be a little and valley-skipping mode may take place slightly osc . BLANK Doc ID 16610 Rev 1 L6566BH osc < in''' in'' after MOSFET’s BLANK = 150 kHz, the osc Section 5 ...

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... L6566BH start-up, at the end of the soft-start phase the output voltage of the converter must meet the condition: Equation 4 where Ns is the turn number of the secondary winding, Naux the turn number of the auxiliary winding and I The operation described so far under different operating conditions for the converter is ...

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... Burst-mode operation at no load or very light load When the voltage at the COMP pin (9) falls 20 mV below a threshold fixed internally at a value depending on the selected operating mode, the L6566BH is disabled with COMPBM the MOSFET kept in OFF state and its consumption reduced at a lower value to minimize Vcc capacitor discharge ...

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... Vref 10 4 L6566BH 7 3 and Vcc has exceeded the normal UVLO threshold (see Vcc UVLO Vcc Vcc OFF2 OFF1 (*) L6566BH Doc ID 16610 Rev 1 Application information internally fixed have more COMPO Figure 13 VCOMP (pin 9) V COMPL V COMPO Vcc (pin 5) Vcc OFF1 Vcc ...

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... The dynamics of the pin is in the 2 range. The voltage at the pin is clamped downwards at about the clamp is externally overridden and the voltage on the pin is pulled below 1.4 V the L6566BH will shut down. This condition is latched as long as the device is supplied. While the device is disabled, however, no energy is coming from the self- supply circuit, thus the voltage on the Vcc capacitor will decay and cross the UVLO threshold after some time, which clears the latch and lets the HV generator restart ...

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... L6566BH Figure 15. Externally controlled burst-mode operation by driving pin COMP: timing diagram Vcc (pin 5) Vcc Vcc OFF Vcc restart COMP (pin 9) GD (pin 4) Vcc_OK I charge 0.85 mA Vout 5.6 PWM comparator, PWM latch and voltage feedforward blocks The PWM comparator senses the voltage across the current sense resistor Rs and, by comparing it to the programming signal delivered by the feedforward block, determines the exact time when the external MOSFET switched off ...

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... V = ⋅ opt ⋅ min in max in min Doc ID 16610 Rev 1 L6566BH Figure 17 on page 27 (with the error amplifier csx k Vin opt 3 3.5 4 can be found: opt ) + ⋅ max ...

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... Rs I PKp Rectified Line Voltage R1 = Upper clamp R2 COMP 9 2.5 3 3.5 L6566BH > Pout @ Vin the system is still undercompensated and k needs lim min @ Vin < Pout @ Vin lim max lim in this way possible that Pout opt ”). The overcurrent setpoint will be then fixed at the maximum value of ...

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... If in the next switching cycle the comparator is not tripped, a temporary disturbance is assumed and the protection logic will be reset in its idle state; if the comparator will be tripped again a real malfunction is assumed and the L6566BH will be stopped. Depending on the time 28/48 = ...

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... This is what naturally occurs with QR operation, due to the twice-mains- frequency ripple appearing on the input bulk capacitor, which translates into different DCM- CCM boundary frequencies. The L6566BH is provided with a dedicated pin, FMOD (6), to perform this function if FF mode is selected. Figure 19. Frequency modulation circuit ...

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... HV generator in this way cuts its power dissipation approximately by three (as compared to the case of continuous conduction) and keeps peak silicon temperature close to the average value. To let the L6566BH restart it is then necessary to disconnect the converter from the input source. Pulling pin 16 (AC_OK) below the disable threshold (see protection on page 35 latch can be cleared and a quicker restart is allowed as the input source is removed ...

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... L6566BH This function is useful to implement a latched overtemperature protection very easily by biasing the pin with a divider from VREF, where the upper resistor is an NTC physically located close to a heating element like the MOSFET, or the transformer. The DIS pin is a high impedance input, thus it is prone to pick up noise, which might give origin to undesired latch-off of the device ...

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... A control loop failure results in an output overvoltage that is handled by the OVP function of the L6566BH (see next section). In case of QR operation, a short circuit causes the converter to run at a very low frequency, then with very low power capability ...

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... An internal current generator is activated that sources 1 mA out of the VFF pin (15). If the VFF voltage is allowed to reach 2 Vbe over 5 V, the L6566BH will be latched off. See Latched disable function on page 30 conditions. If the impedance externally connected to pin low that the 5+2 V threshold cannot be reached or if some means is provided to prevent that, the device will be able to restart after the Vcc has dropped below 5 V. Refer to the “ ...

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... OVP comparator is active only for a small time window (typically, 0.5 µs) starting 2 µs after MOSFET’s turn-off, to reject the voltage spike associated to the positive-going edges of the voltage across the auxiliary winding Vaux; second, to stop the L6566BH the OVP comparator must be triggered for four consecutive switching cycles. A counter, which is reset every time the OVP comparator is not triggered in one switching cycle, is provided to this purpose ...

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... RMS current. Secondly, spurious restarts may occur during converter power down, hence causing the output voltage not to decay to zero monotonically. L6566BH shutdown upon brownout is accomplished by means of an internal comparator, as shown in the block diagram of inverting input of the comparator, available on the AC_OK pin (16), is supposed to sense a voltage proportional to the RMS (peak) mains voltage ...

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... and R , yield − ⋅ Vsen . 1 078 Vsen = ON OFF ; − ⋅ Doc ID 16610 Rev 1 ON Vsen Vsen OFF VAC_OK 0.485V (pin 16) AC_FAIL I HYS 15 µA Vcc (pin 5) GD (pin 4) Vout − Vsen . OFF − Vsen . 0 45 OFF L6566BH t 0.45V ...

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... F Doc ID 16610 Rev 1 Application information AC mains (L/ AC_OK VFF OVP settings b) have been found as suggested above, L will be split as − lower than the minimum voltage on OFF HVstart is large enough, F needs to be quite a big capacitor (in the uF) L6566BH Optionalfor must be lower in order for 37/48 ...

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... Note also that the burst-mode threshold (in terms of power) will be slightly changed. If slope compensation is not required with FF operation, the pin shall be left floating. 38/48 GD (pin 4) Figure 27 Doc ID 16610 Rev external component other than the L6566BH ...

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... Summary of L6566BH power management functions The device is provided with a number of power management functions: multiple operating mode upon loading conditions and protection functions. To help the designer familiarize with these functions, in the following tables, all themes are summarized with their respective activation mechanism and the resulting status of the most important pins. This can be useful not only for a correct use of the IC but also for diagnostic purposes: especially at prototyping/debugging stage quite common to bump into unwanted activation of some function, and these tables can be used as a sort of quick troubleshooting guide ...

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... Table 6. L6566BH protections (continued) Protection Description Caused by V > Transformer saturation or for 2-3 nd shorted secondary diode 2 OCP consecutive protection switching cycles Externally set-able V >V DIS overtemperature protection OTP Internal thermal shutdown T > 160 j Mains undervoltage V Brownout AC_OK protection Reference V drift protection V REF ...

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... L6566BH 6 Application examples and ideas Figure 28. Typical low-cost application schematic Figure 29. Typical full-feature application schematic (QR operation) Application examples and ideas Doc ID 16610 Rev 1 41/48 ...

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... OVP latched SS VREF AC_OK L6566BH R FF VFF 15 R ≈ 1N4148 SS VREF AC_OK L6566BH VFF Doc ID 16610 Rev 1 L6566BH OVP auto-restart SS VREF R H AC_OK L6566BH VFF − ⋅ ≥ 6 Diode needed 1N4148 SS VREF R H AC_OK L6566BH VFF R L2 − ⋅ ≥ Diode needed ...

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... Figure 31. Frequency foldback at light load (FF operation) Figure 32. Latched shutdown upon mains overvoltage Vcc L6566BH MODE/SC Vref 12 10 COMP 9 L6566BH 13 OSC R T Vin BC847 5 DIS 8 15 VFF >10 Rq Doc ID 16610 Rev 1 Application examples and ideas R1 R2 BC857C Vin BC857 Vref DIS 10 8 L6566BH 15 VFF Rq 43/48 ...

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... Package mechanical data 7 Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ® ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at: www.st.com. ® ECOPACK trademark. 44/48 Doc ID 16610 Rev 1 L6566BH ® ...

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... L6566BH Table 8. SO16N mechanical data Dim Figure 33. Package dimensions mm. Min Typ Max 1.75 0.1 0.25 1.6 0.35 0.46 0.19 0.25 0.5 45° 9.8 10 5.8 6.2 1.27 8.89 3.8 4.0 4.60 5.30 0.4 1.27 0.62 Doc ID 16610 Rev 1 Package mechanical data inch ...

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... Order codes 8 Order codes Table 9. Order codes Order codes L6566BH L6566BHTR 46/48 Package SO16N SO16N Doc ID 16610 Rev 1 L6566BH Packaging Tube Tape and reel ...

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... L6566BH 9 Revision history Table 10. Document revision history Date 30-Nov-2009 Revision 1 First release Doc ID 16610 Rev 1 Revision history Changes 47/48 ...

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... Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America 48/48 Please Read Carefully: © 2009 STMicroelectronics - All rights reserved STMicroelectronics group of companies www.st.com Doc ID 16610 Rev 1 L6566BH ...