L6699DTR STMicroelectronics, L6699DTR Datasheet

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... Enhanced high voltage resonant controller Applications ■ SMPS for LCD TVs, desktop and AIO PCs, servers, Telecom power ■ AC-DC adapter, open frame SMPS Table 1. Device summary Order codes L6699D L6699DTR Doc ID 022835 Rev 2 L6699 − Datasheet production data Package Packing Tube SO16N Tape and reel 1/38 www ...

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Contents Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

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L6699 List of figures Figure 1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

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Description 1 Description The L6699 is a double-ended controller specific to series-resonant half bridge topology. Both LLC and LCC configurations are supported. It provides symmetrical complementary duty cycle: the high-side switch and the low-side switch are driven ON/OFF 180° out-of- ...

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L6699 2 Electrical ratings Table 2. Absolute maximum ratings Symbol Pin V 16 BOOT HVG OUT dV /dt 14 OUT LVG PFC_STOP I 9 PFC_STOP V 7 LINEmax I 4 RFmin ...

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Pin connections 4 Pin connections Figure 2. Pin connections (top view) Table 4. Pin functions N. Name DELAY 3 CF 6/38 Soft-start. This pin connects an external capacitor to GND and a resistor to RF (pin ...

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L6699 Table 4. Pin functions (continued) N. Name 4 RF min 5 STBY 6 ISEN 7 LINE 8 DIS 9 PFC_STOP Minimum oscillator frequency setting. This pin provides an accurate 2 V reference, and a resistor connected from this pin ...

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Pin connections Table 4. Pin functions (continued) N. Name 10 GND 11 LVG N.C. 14 OUT 15 HVG 16 V BOOT Figure 3. Typical system block diagram 8/38 Chip ground. Current return for both the low-side ...

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L6699 5 Electrical data Tj = -25 to +125 ° KΩ; unless otherwise specified. min Table 5. Electrical characteristics Symbol Parameter Ic supply voltage V Operating range CC V Turn-on threshold CCOn V Turn-off threshold CCOff Hys ...

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Electrical data Table 5. Electrical characteristics (continued) Symbol Parameter Deadtime self-adjustment ( range V Peak value CFp V Valley value CFv V Voltage reference on pin 4 REF K Current mirroring ratio M RF Timing resistor range min ...

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L6699 Table 5. Electrical characteristics (continued) Symbol Parameter I Peak source current sourcepk I Peak sink current sinkpk t Fall time f t Rise time r UVLO saturation High-side gate driver (voltages referred to out) V Output low voltage LVGL ...

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Application information 6 Application information The L6699 is an advanced double-ended controller specific to resonant half bridge topology. In these converters the MOSFETs of the half bridge leg are alternately switched on and off (180° out-of-phase) for exactly the same ...

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L6699 6.1 Oscillator The oscillator is programmed externally by means of a capacitor (CF), connected from pin 3 (CF) to ground, that is alternately charged and discharged by the current defined with the network connected to pin ...

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Application information After fixing CF according to Table 6. Recommended values for function of the startup frequency f f [kHz] start 150 160 170 180 190 – 200 210 220 Value of RF and RF min entire ...

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L6699 6.2 Adaptive deadtime A deadtime T inserted between the turn-off of either switch and the turn-on of the D complementary one, where both switches are in the OFF-state, is essential to achieve soft- switching. Its value must be larger ...

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Application information Figure 7. Adaptive deadtime: principle schematic Note that the “Driving logic…” block sets a minimum deadtime T which T cannot go, to prevent simultaneous conduction of the high-side and the low-side D switch, and also a maximum deadtime ...

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L6699 There are three contributors to T ● The turn-off delay t characteristics of the specific MOSFET and the speed its gate is driven ● The transition time T ● The detection time t the gate-drive signal of the other ...

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Application information Figure 10. Comparison startup behavior: traditional controller (left), with L6699 (right) A non-zero initial voltage on the resonant capacitor may cause the very first turn-on of the high-side MOSFET to occur with non-zero drain-to-source voltage while the body ...

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L6699 Figure 11. Comparison of initial cycles after startup: traditional controller (left), with L6699 (right) It goes without saying that when either MOSFET is turned on for the very first time, this occurs with a non-zero drain-to-source voltage. Therefore, strictly ...

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Application information the operating frequency is essentially determined by the current sunk by the optocoupler's phototransistor. During this frequency sweep phase the operating frequency decays following the exponential charge of C gets slower and slower. This counteracts the non-linear frequency ...

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L6699 7 Operation at no load or very light load When the resonant half bridge is lightly loaded or totally unloaded, its switching frequency reaches its maximum value. To keep the output voltage under control and avoid losing soft- switching ...

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Operation at no load or very light load Equation 6 Note that, unlike the f some load Pout B transformer's peak currents are low enough not to cause audible noise. The resonant converter's switching frequency, however, depends also on the ...

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L6699 Figure 17. How the L6699 can switch off a PFC controller at light load Vcc 12 L6699 To help the user meet energy saving requirements even in power-factor-corrected systems, where a PFC pre-regulator precedes the DC-DC converter, the L6699 ...

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Current sensing, OCP and OLP 8 Current sensing, OCP and OLP In the L6699 the current sense input ISEN (pin 6) senses the current flowing in the resonant tank to perform multiple tasks: 1. Primary overcurrent protection (OCP function). 2. ...

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L6699 The ISEN pin, which is also able to withstand negative voltages, is internally connected to the input of a first comparator, referenced to second comparator referenced to 1.5 V. The operation of the second comparator is described later. If ...

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Current sensing, OCP and OLP therefore providing the system with immunity to short duration phenomena. If, instead exceeded, an overload protection (OLP) procedure is activated that shuts down the L6699 and, in case of continuous overload/short-circuit, results in ...

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L6699 Figure 20. Soft-start and delayed shutdown upon overcurrent timing diagram (safe- start details are not shown) In applications where continuous operation of the converter is needed even under overload conditions, the delayed shutdown function can be disabled by simply ...

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Capacitive-mode detection function 9 Capacitive-mode detection function Normally, the resonant half bridge converter operates with the resonant tank current lagging behind the square-wave voltage applied by the half bridge leg, like a circuit having a reactance of an inductive nature. ...

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L6699 4. When either MOSFET is turned on, the other one can be parasitically turned on too, if the current injected through its Cgd and flowing through the gate driver's pull-down is large enough to raise the gate voltage close ...

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Line sensing function 10 Line sensing function This function basically stops the IC as the input voltage to the converter falls below the specified range and lets it restart as the voltage goes back within the range. The sensed voltage ...

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L6699 Figure 22. Line sensing function: internal block diagram and timing diagram While the line undervoltage is active there is no switching activity, therefore the V (if not supplied by another source) continuously oscillates between the startup and the UVLO ...

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Latched shutdown 11 Latched shutdown The L6699 is equipped with a comparator having the non-inverting input externally available on pin 8 (DIS) and with the inverting input internally referenced to 1. the voltage on the pin exceeds the ...

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L6699 Figure 23. Bootstrap supply: standard circuit This concern applies to converters designed with a high resonance frequency (indicatively, > 150 kHz), so that they run at high frequency also at full load. Otherwise, the converter runs at high frequency ...

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Package information 13 Package information 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: is ...

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L6699 Figure 26. Package drawing Doc ID 022835 Rev 2 Package information 0016020_F 35/38 ...

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Package information Figure 27. Recommended footprint (dimensions are in mm) 36/38 Doc ID 022835 Rev 2 L6699 ...

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L6699 14 Revision history Table 7. Document revision history Date 12-Apr-2012 16-Jan-2013 Revision 1 Initial release. 2 Updated Table 2: Absolute maximum ratings on page 5 Doc ID 022835 Rev 2 Revision history Changes . 37/38 ...

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