L6591 STMicroelectronics, L6591 Datasheet

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... Ilimre max. OCP - 3R SOFT-STAR Doc ID 14821 Rev 5 SO16 narrow Vre f VREG Sync hronou s bo otstra p diode DIS _CT L L EVEL R SHIFTER DIS S HUT NE_ OK VREG 0.3 2mA + - COMP L6591 6 VREF 1 5 BOOT 1 4 HVG 1 3 FGND GND 1/41 www.st.com 41 ...

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... Oscillator and dead-time programming . . . . . . . . . . . . . . . . . . . . . . . . . . 28 6.7 Adaptive UVLO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 6.8 Line sensing function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 6.9 Soft-start and delayed latched shutdown upon overcurrent . . . . . . . . . . . 32 7 Summary of L6591 power management functions . . . . . . . . . . . . . . . 34 8 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 9 Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 10 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 2/41 Doc ID 14821 Rev 5 L6591 ...

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... L6591 1 Description The L6591 is a double-ended PWM controller specific for the soft-switched half-bridge topology. It provides complementary PWM control, where the high-side switch is driven ON for a duty cycle D and the low-side switch for a duty cycle 1-D, with D < 50%. An externally programmable dead-time inserted between the turn-off of one switch and the turn-on of the other one guarantees soft-switching and enables high-frequency operation ...

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... IC: the latch is removed as the voltage on the Vcc pin (#9) goes below the UVLO threshold. Connect the pin to GND (#11) if the function is not used. Doc ID 14821 Rev 5 HVSTART BOOT HVG FGND N.C. GND LVG 9 Vcc Function L6591 ...

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... L6591 Table 1. Pin functions (continued) Pin N. Name 3 ISEN OSC 6 VREF 7 COMP 8 PFC_STOP Function Current sense (PWM comparator) input. The voltage on this pin is internally compared with an internal reference derived from the voltage on pin COMP and when they are equal the high-side gate drive output (previously asserted high by the clock signal generated by the oscillator) is driven low to turn off the upper power MOSFET ...

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... Normally it is re-enabled when the voltage on the Vcc pin falls below 5 V, except under latched shutdown conditions, in which case it is re-enabled as the Vcc voltage falls 1 V below the start-up threshold to keep the latch active. Doc ID 14821 Rev 5 L6591 ...

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... L6591 3 Electrical data 3.1 Maximum ratings Table 2. Absolute maximum ratings Symbol Pin V 16 HVSTART I 16 HVS V 15 BOOT V 13 FGND dV /dt 13 FGND 10, 14 HVG LVG I 8 PFC_STOP V 1 LINEmax --- ISEN 3 P TOT STG 3.2 Thermal data Table 3. Thermal data Symbol R Thermal resistance junction to ambient thJA 1 ...

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... Doc ID 14821 Rev nF kΩ, C LVG T T Min Typ Max 11 9.7 10.5 11.3 COMPL 8.2 8.7 9.2 COMPL 3.0 3 190 250 2.8 3.5 5.3 8 0.35 2.2 0.35 17 500 800 = 10 125 700 0.55 0.75 1 L6591 = 330 pF; Unit µ µA µA Ω ...

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... L6591 Table 4. Electrical characteristics (continued) Symbol I ON-state current HV Leakage current (OFF-state) V HV, OFF V HV generator restart voltage CCrestart Reference voltage V Output voltage REF V Total variation REF I Short circuit current REF Sink capability in UVLO Current sense comparator I Input bias current ISEN t Leading edge blanking ...

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... > 1 3.4 4.7 COMPH 3.4 4.7 2 4.85 5 COMPH 6.4 COMPH = Vcc, 12.8 13.3 -0.3 0 L6591 Max Unit -1 µA V 190 kHz 192 kHz 3.15 V 1.05 V µs 22 µA 5.6 5.6 µ µA 0 ...

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... L6591 Table 4. Electrical characteristics (continued) Symbol UVLO saturation High-side gate driver (voltages referred to FGND) V Output low voltage HVGL V Output high voltage HVGH I Peak source current sourcepk I Peak sink current sinkpk t Fall time f t Rise time r Pull-down resistor 1. Parameters in tracking each other 2 ...

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... Typical characteristics 5 Typical characteristics Figure 4. High-voltage generator ON-state sink current vs. Tj Figure 6. High-voltage generator start voltage vs. Tj 12/41 Figure 5. High-voltage generator output (Vcc charge current) vs. Tj Figure 7. High-voltage generator Vcc restart voltage vs. Tj Doc ID 14821 Rev 5 L6591 ...

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... L6591 Figure 8. IC consumption during normal operation vs. Tj Figure 10. Start-up & UVLO vs. Tj Figure 9. IC consumption under protection and before turn-on vs. Tj Figure 11. Vcc Zener voltage vs. Tj Doc ID 14821 Rev 5 Typical characteristics 13/41 ...

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... Typical characteristics Figure 12. COMP voltage upper clamp level vs. Tj Figure 14. COMP dynamic resistance vs. Tj 14/41 Figure 13. COMP source current vs. Tj Figure 15. Oscillator frequency vs. Tj Doc ID 14821 Rev 5 L6591 ...

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... L6591 Figure 16. Oscillator ramp vs. Tj Figure 18. Current sense clamp vs. Tj Figure 17. Max. duty-cycle vs. Tj Figure 19. Disable level on current sense vs. Tj Doc ID 14821 Rev 5 Typical characteristics 15/41 ...

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... Typical characteristics Figure 20. Reference voltage vs. Tj Figure 22. Soft-start charge current vs. Tj 16/41 Figure 21. DIS threshold vs. Tj Figure 23. Soft-start discharge current vs. Tj Doc ID 14821 Rev 5 L6591 ...

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... L6591 Figure 24. UVLO saturation vs. Tj Figure 26. Soft-start disable and latch-off levels vs. Tj Figure 25. Soft-start clamp voltage vs. Tj Figure 27. High side pull-down resistor vs. Tj Doc ID 14821 Rev 5 Typical characteristics 17/41 ...

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... Typical characteristics Figure 28. low side gate-drive output low saturation Figure 30. Gate-drives output high voltage vs. Tj 18/41 Figure 29. Gate-drives output low voltage vs. Tj Figure 31. High side pull-down resistor vs. Tj Doc ID 14821 Rev 5 L6591 ...

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... L6591 Figure 32. Burst mode thresholds vs. Tj Figure 34. Line sensing threshold vs. Tj Figure 33. Burst mode hysteresis vs. Tj Figure 35. Line sensing current hysteresis vs. Tj Doc ID 14821 Rev 5 Typical characteristics 19/41 ...

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... Typical characteristics Figure 36. Dead time vs. Tj Figure 38. Dead time vs. R 20/41 Figure 37. Oscillator frequency vs Doc ID 14821 Rev 5 L6591 , ...

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... L6591 6 Application information The L6591 is an advanced current-mode PWM controller specific for fixed-frequency, peak- current-mode-controlled ZVS half-bridge converters. In these converters the switches (MOSFET’s) are controlled with complementary duty cycle: the high-side MOSFET is driven ON for a duty cycle D and the low-side MOSFET for a duty cycle 1-D. For a proper operation the maximum allowed duty cycle must be limited below 50% ...

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... Figure 40. High-voltage start-up generator: internal schematic 22/41 Figure 41, when power is first applied to the ≈ 400 Vdc), typically 50-70 times lower, under the same   L6591 15 M & Ω Vcc_OK HV_EN CONT ROL Doc ID 14821 Rev 5 H VST ART Vcc I charge L6591 ...

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... The low restart threshold Vcc the L6591 will have a very low repetition rate, as shown in the timing diagram of and that the converter will work safely with extremely low power throughput. The restart threshold of the HV generator is changed when any latched disable function of the IC is invoked to ensure a real latch-off. For more details see “ ...

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... DC offset on the current sense pin as shown in Note: The offset reduces the available dynamics of the current signal; thereby, the value of the sense resistor must be determined taking this offset into account. 24/41 Figure 43 Doc ID 14821 Rev 5 L6591 illustrates this kind of Figure 44. ...

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... IC is idle during burst-mode operation. This signal will be externally used for switching off the PFC controller and the pre-regulator as shown in Figure 45. When the L6591 is in UVLO the pin is kept open, to let the PFC controller starts first. Bu rst-   ...

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... Application information Figure 45. How the L6591 can switch off a PFC controller at light load Vref Vref 6 6 L6591 L6591 8 8 6.3 PWM control block The device is specific for secondary feedback. Typically, there is a TL431 at the secondary side and an optocoupler that transfers output voltage information to the PWM control at the primary side, crossing the isolation barrier. The PWM control input (pin #7, COMP) is driven directly by the phototransistor’ ...

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... PFC _S top 6.5 Latched shutdown The L6591 is equipped with a comparator having the non-inverting input externally available at the pin DIS (#2) and with the inverting input internally referenced to 4 the voltage on the pin exceeds the internal threshold, the IC is immediately shut down and its consumption reduced at a low value ...

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... ene turn gen erator tu rn- isabl Inpu t sou rce moved he re 1150 = + ( ) − − ⋅ 125 10 osc d − 1200 = ⋅ ⋅ − osc T T and C , the oscillator frequency ( Doc ID 14821 Rev 5 L6591 t Disa ble la tch set h ere osc ...

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... L6591 Equation 3 During the negative-going ramp of the sawtooth a clock pulse is released flip-flop, along with a logic circuit, separates the odd and the even clock pulses. The even ones turn off the low-side MOSFET first and, after a dead time T the high-side MOSFET is turned off (and the low-side MOSFET turned on after the dead time response to the control loop ...

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... MOSFETS with a sufficient gate-drive voltage at heavy load during power off. To help the designer overcome this problem, the L6591, besides reducing its own consumption during burst-mode operation, also features a proprietary adaptive UVLO function. It consists of shifting the UVLO threshold downwards at light load, namely when the voltage at pin COMP falls below a threshold V more headroom ...

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... PFC pre-regulator front-end, the output voltage of the PFC stage, in which case the function will serve as a power-on and power-off sequencing. L6591 shutdown upon input under voltage is accomplished by means of an internal comparator, as shown in the block diagram of available at the LINE pin (#1). The comparator is internally referenced to 1.25 V and disables the IC if the voltage applied at the LINE pin is below the internal reference ...

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... and R , yield − Vin Vin = ON OFF − ⋅ from zero up to about 2 V where it is SS1 Doc ID 14821 Rev 5 − Vin . OFF − Vin . 1 25 OFF Figure L6591 ...

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... While in case of feedback loop failure the system must be stopped quickly to prevent the output voltage from reaching too high values, an overload or a short circuit does not generally need such fast intervention. The L6591 makes it easier to handle such conditions: the 2 V clamp on the SS pin is removed and a second internal current generator I /4 keeps on charging Css ...

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... Summary of L6591 power management functions 7 Summary of L6591 power management functions It has been seen that the device is provided with a number of power management functions: different operating mode upon loading conditions, protection functions, as well as interaction with the PFC pre-regulator. To help the designer familiarize with these functions, in the following tables all of theme are summarized with their respective activation mechanism and the resulting status of the most important pins ...

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... Summary of L6591 power management functions Vcc ...

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... Summary of L6591 power management functions Figure 52. L6591 typical application: 180 W, WRM, power-factor-corrected AC-DC adapter BD1 FBI 6K5F1 F1 T4A LF1-A LF2-A CX1 CX2 Vin = 88 to 264 LF1-B LF2-B NTC1 10 C10 10n PFC_STOP DIS V REF 1/ 2 PC817A 3 4 OC2B NTC1 TBD C15 ...

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... L6591 8 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. Table 7. SO16 narrow mechanical data Dim ccc mm Min. ...

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... Package mechanical data Figure 53. SO16 narrow mechanical data 38/41 Doc ID 14821 Rev 5 L6591 ...

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... L6591 9 Order codes Table 8. Order codes Order codes L6591 L6591TR Package SO16N SO16N Doc ID 14821 Rev 5 Order codes Packaging Tube Tape and reel 39/41 ...

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... Revision 1 Initial release 2 Updated: Section 1: Description on page 3 3 Updated: Table 4 on page 8 4 Updated: Table 4 on page Added: Section 5 on page 12 5 Updated: Figure 1 on page Doc ID 14821 Rev 5 L6591 Changes 8, Section 6.7 on page 30 1, Table 4 on page 8 ...

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... L6591 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. ...