EVL6566B-65W STMicroelectronics, EVL6566B-65W Datasheet
EVL6566B-65W
Specifications of EVL6566B-65W
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EVL6566B-65W Summary of contents
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Features ■ Selectable multi-mode operation: fixed frequency or quasi-resonant ■ On-board 700 V high-voltage start-up ■ Advanced light load management ■ Low quiescent current (< 3 mA) ■ Adaptive UVLO ■ Line feedforward for constant power capability vs mains voltage ...
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Contents Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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L6566B 6 Application examples and ideas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 7 Package mechanical ...
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List of tables List of tables Table 2. Pin functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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L6566B List of figures Figure 1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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Description 1 Description The L6566B is an extremely versatile current-mode primary controller ICs, specifically designed for high-performance offline flyback converters 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 ...
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L6566B Figure 2. Typical system block diagram Rectified & Filtered Mains Voltage FLYBACK DC-DC CONVERTER L6566B Description V outdc 7/51 ...
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Pin settings 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 700 tied directly to the rectified ...
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L6566B Table 1. Pin functions (continued) N° Pin Supply voltage of both the signal part of the IC and the gate driver. The internal high voltage generator charges an electrolytic capacitor connected between this pin and GND (pin 3) as ...
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Pin settings Table 1. Pin functions (continued) N° Pin Transformer demagnetization sensing input for quasi-resonant operation and OVP input. The pin is externally connected to the transformer’s auxiliary winding through a resistor divider. A negative-going edge triggers MOSFET’s turn-on if ...
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L6566B 3 Electrical data 3.1 Maximum rating Table 2. Absolute maximum ratings Symbol Pin V HVS I HVS FMOD 10, 14 max V 9, 15, 16 max I 11 ZCD V 12 MODE/SC V ...
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Electrical characteristics 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 ...
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L6566B Table 4. Electrical characteristics (continued) Symbol Parameter Reference voltage V Output voltage REF V Total variation REF I Short circuit current REF Sink capability in UVLO V Overvoltage threshold OV Internal oscillator f Oscillation frequency sw V Voltage reference ...
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Electrical characteristics Table 4. Electrical characteristics (continued) Symbol Parameter Current sense comparator I Input bias current CS t Leading edge blanking LEB td Delay to output (H-L) V Overcurrent setpoint CSx V Hiccup-mode OCP level CSdis PWM control V Upper ...
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L6566B Table 4. Electrical characteristics (continued) Symbol Parameter Zero current detector/ overvoltage protection V Upper clamp voltage ZCDH V Lower clamp voltage ZCDL V Arming voltage ZCDA V Triggering voltage ZCDT I Internal pull-up ZCD I Source current capability ZCDsrc ...
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Electrical characteristics Table 4. Electrical characteristics (continued) Symbol Parameter Soft-start I SS1 Charge current I SS2 I Discharge current SSdis V High saturation voltage SSclamp V Disable level SSDIS V Latch-off level SSLAT Gate driver V Output high voltage GDH ...
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L6566B 5 Application information The L6566B is a versatile peak-current-mode PWM controller specific for offline flyback converters. The device allows either fixed-frequency (FF) or quasi-resonant (QR) operation, selectable with the pin MODE/SC (12): forcing the voltage on the pin over ...
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Application information If FF operation is selected mode from heavy to light load. The system operates exactly like a standard current mode control frequency f both DCM and CCM transformer operation are possible, depending on whether ...
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L6566B 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. ...
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Application information Figure 7. Timing diagram showing short-circuit behavior (SS pin clamped Vcc (pin 5) Vcc ON Vcc OFF Vcc restart GD (pin 4) Vcc_OK I charge 0.85 mA Figure 8. Zero current detection block, triggering block, ...
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L6566B 5.2 Zero current detection and triggering block; oscillator block The zero current detection (ZCD) and triggering blocks switch on the external MOSFET if a negative-going edge falling below applied to the input (pin 11, ZCD). To ...
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Application information Figure 9. Drain ringing cycle skipping as the load is gradually reduced osc in' (limit condition) Note: When the system operates in valley skipping-mode, uneven ...
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L6566B 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 ...
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Application information 5.3 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 ...
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L6566B Figure 12. Addition of an offset to the current sense lowers the burst-mode operation threshold 5.4 Adaptive UVLO A major problem when optimizing a converter for minimum no-load consumption is that the voltage generated by the auxiliary winding under ...
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Application information 5.5 PWM control block The device is specific for secondary feedback. Typically, there is a TL431 on the secondary side and an optocoupler that transfers output voltage information to the PWM control on the primary side, crossing the ...
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L6566B 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 ...
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Application information setpoint. This is illustrated in the diagram on the left-hand side of shows the relationship between the voltage on the pin VFF and V saturated high in the attempt of keeping output voltage regulation): Equation 5 Figure 16. ...
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L6566B Experience shows that this value is typically lower than the real one. Once the maximum peak primary current, I the value of Rs can be determined from (5): Equation 7 Figure 17. Left: overcurrent setpoint vs VFF voltage; right: ...
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Application information Equation 8 where Lp is the inductance of the primary winding. In case a constant maximum power capability vs. the input voltage is not required, the VFF pin can be grounded, directly or through a resistor (see setpoint ...
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L6566B between the detected event and the oscillator, occasionally the device could stop after the third detection. This condition is latched as long as the device is supplied. While it is disabled, however, no energy is coming from the self-supply ...
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Application information Equation 9 which is the parameter that the amplitude of the generated side-band harmonics depends on. The minimum frequency f frequency f sw_max around the centre value f Equation 10 Then, R will be found from (5) (see ...
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L6566B 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 ...
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Application information The soft-start pin is also invoked whenever the control voltage (COMP) saturates high, which reveals an open-loop condition for the feedback system. This condition very often occurs at start-up, but may be also caused by either a control ...
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L6566B 5.11 OVP block The OVP function of the L6566B monitors the voltage on the ZCD pin (11) in MOSFET’s OFF-time, during which the voltage generated by the auxiliary winding tracks converter’s output voltage. If the voltage on the pin ...
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Application information Figure 23. OVP function: timing diagram GD (pin 4) Vaux 0 ZCD (pin 11) 5V COUT 2 µs STROBE OVP COUNTER RESET COUNTER STATUS 0 0 FAULT NORMAL OPERATION The value capability of the internal ...
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L6566B Equation 15 where µs; this is also illustrated in the diagram of BLANK2 Figure 24. Maximum allowed duty cycle vs switching frequency for correct OVP detection Dmax 5.12 Brownout protection Brownout protection is basically a not-latched ...
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Application information Figure 25. Brownout protection: internal block diagram and timing diagram Sensed voltage L6566B R H AC_OK 16 15 µ The brownout comparator is provided with current hysteresis in addition to voltage hysteresis: an internal 15 µA ...
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L6566B Figure 26. Voltage sensing techniques to implement brownout protection with the L6566B HV Input bus R H AC_OK R L1 VFF typically convenient to use a single divider to bias both the AC_OK ...
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Application information 5.13 Slope compensation The pin MODE/SC (12), when not connected to VREF, provides a voltage ramp during MOSFET’s ON-time synchronous to that of the internal oscillator sawtooth, with 0.8 mA minimum current capability. This ramp is intended for ...
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L6566B 5.14 Summary of L6566B power management functions It has been seen that 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 ...
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Application information Table 6. L6566B protections Protection Description Caused by V >V ZCD for 4 h consecutive Output switching OVP overvoltage cycles protection VFF > VFFlatch V COMP =V COMPHi V > SS Output V SSDIS OLP overload V protection ...
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L6566B Table 6. L6566B protections (continued) Protection Description Caused by Shutdown V COMP Shutdown2 by V COMP V COMPOFF low Shutdown V < 9. going ( cc VCOMP V below V COMPL ccoff ADAPTIVE (lowering of UVLO ...
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Application examples and ideas 6 Application examples and ideas Figure 28. Typical low-cost application schematic F1 NTC1 fuse Vin CY1 88 to CX1 CX2 264 Vac Lx CY2 R3 470k FMOD AC_OK DIS IC1 VFF 15 L6566B ...
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L6566B Figure 30. Typical full-feature application schematic (FF operation) F1 NTC1 fuse Vin CY1 88 to CX1 CX2 264 Vac Lx R15 MODE/SC AC_OK 12 16 R14 IC1 VFF 15 L6566B DIS VREF FMOD OSC R13 ...
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Application examples and ideas Figure 31. Frequency foldback at light load (FF operation) Figure 32. Latched shutdown upon mains overvoltage L6566B 46/51 MODE/SC Vref L6566B 13 OSC R T Vin Vcc BC847 5 DIS 8 15 VFF ...
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L6566B 7 Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK packages. These packages have a lead-free second level interconnect. The category of second Level Interconnect is marked on the package and on the ...
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Package mechanical data Table 8. SO16N mechanical data Dim Figure 33. Package dimensions 48/51 mm. Min Typ Max 1.75 0.1 0.25 1.6 0.35 0.46 ...
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L6566B 8 Order codes Table 9. Order codes Order codes L6566B L6566BTR Package Packaging SO16N SO16N Tape and reel Order codes Tube 49/51 ...
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Revision history 9 Revision history Table 10. Document revision history Date 20-Aug-2007 29-May-2008 02-Dec-2008 50/51 Revision 1 First release 2 Updated Figure 29 on page 3 Updated Figure 1 on page 1 L6566B Changes 44, Table 2 on page 11 ...
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... L6566B Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. ...