Datasheet HVLED007 (STMicroelectronics) - 4

Pin connections HVLED007 2 Pin connections Figure 2. Pin connection (top view)
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Table 3. Thermal data Symbol Parameter Value Unit
Rth j-amb Max. thermal resistance, junction-to-ambient 150 °C/W
Table 4. Pin functions N. Name Function
Input current shaper (ICS) circuit. A capacitor connected from this pin to ground 1 CT (pin #6) is alternately charged and discharged internally, and the voltage developed across this capacitor is used as the reference for the current loop. Control input for PWM regulation. The pin is driven by the phototransistor (emitter- grounded) of an optocoupler to modulate its voltage by modulating the current sunk. A capacitor placed between the pin and ground (pin #6), as close to the IC 2 COMP as possible to reduce noise pick-up, is useful to get a clean control voltage. The dynamics of the pin are in the 2.5 to 5.5 V range. A voltage lower than 2.5 V activates burst-mode operation. The voltage at the pin is bottom-clamped at about 2.2 V. Main input to the multiplier. This pin is connected to the rectified mains voltage via 3 MULT a resistor divider. A capacitor placed between the pin and ground (pin #6), as close to the IC as possible is useful to reduce noise pick-up. Input to the PWM comparator. The current flowing in the MOSFET is sensed 4 CS through a resistor, the resulting voltage is applied to this pin and compared with the internal reference generated by the ICS circuit, to determine MOSFET's turn-off. Transformer demagnetization sensing input for transition-mode (quasi-resonant) operation. A negative-going edge triggers MOSFET's turn-on. A voltage exceeding 5.5 V during MOSFET's OFF-time forces an internal discharge of the COMP pin 5 ZCD (#2) below the burst-mode threshold. As a consequence, the IC is temporarily stopped (overvoltage protection). This function is strobed and digitally filtered to increase noise immunity. 6 GND Ground. Current return for both the signal part of the IC and the gate driver. 4/33 DS12866 Rev 1 Document Outline Table 1. Device summary 1 Block diagram Figure 1. Block diagram Table 2. Absolute maximum ratings 2 Pin connections Figure 2. Pin connection (top view) Table 3. Thermal data Table 4. Pin functions (continued) 3 Electrical characteristics Table 5. Electrical characteristics (continued) 4 Application information 4.1 Introduction Figure 3. Input current distortion in Hi-PF QR flyback converters with traditional TM control: current shape and resulting total harmonic distortion and power factor vs. Kv (= Vinpk/VR) ratio 4.2 Input current shaping function - operating principle Figure 4. Hi-PF QR flyback converter with the traditional TM control: current waveforms Figure 5. Input current shaper (ICS) block and its interconnection with HVLED007 control Figure 6. Key waveforms of the ICS circuit in figure 5 Figure 7. Shape of the current reference Vcsref(θ) (5) at different input voltages (i.e. Kv values) 4.3 Operation of a Hi-PF QR flyback converter based on the HVLED007 Table 6. Timing quantities in a HVLED007-based Hi-PF QR flyback converter Table 7. Control quantities in a HVLED007-based Hi-PF QR flyback converter Table 8. Electrical quantities in a HVLED007-based Hi-PF QR flyback converter 4.4 Shaping capacitor (Ct) selection (pin CT) 4.5 Control input for isolated feedback and optocoupler driving (pin COMP) Figure 8. Output characteristic of pin COMP and significant levels 4.6 Multiplier input for input voltage sensing (pin MULT) 4.7 Current sensing input (pin CS). Sense resistor (Rs) selection Figure 9. Effect of ripple on Ct on current sense signal: a) within linear dynamics, close to clamp level; b) signal slightly exceeding clamp level; c) signal exceeding clamp level, with OCP activation 4.8 Zero current detection and triggering block (pin ZCD); starter 4.9 Overload and short-circuit protection (OCP function) Figure 10. Functional schematic of the overload and short-circuit protection function 4.10 Overvoltage protection (OVP function) Figure 11. Functional schematic of the OVP function 4.11 Soft-restart function Figure 12. Functional schematic of the soft restart function 4.12 Suggested step-by-step design procedure of a Hi-PF QR flyback converter based on the HVLED0007 Table 9. Basic electrical specification and key parameters of a Hi-PF QR flyback Figure 13. Typical application schematic (reference for suggested design procedure) 5 Referenced documents 6 Package information Table 10. SO-8 mechanical data Figure 14. Package dimensions 7 Revision history Table 11. Document history