october 2009 doc id 15534 rev 3 1/31 31 l6599at improved high-voltage resonant controller features 50% duty cycle, variable frequency control of resonant half-bridge high-accuracy oscillator up to 500 khz operating frequency two-level ocp: frequency-shift and latched shutdown interface with pfc controller latched disable input burst-mode operation at light load input for power-on/off sequencing or brownout protection non-linear soft-start for monotonic output voltage rise 600 v-rail compatible high-side gate driver with integrated bootstrap diode and high dv/dt immunity -300/700 ma high-side and low-side gate drivers with uvlo pull-down dip16, so16n package guaranteed for extreme temperature ranges applications street lighting lcd and pdp tvs desktop pcs, entry-level servers telecom smps high efficiency industrial smps ac-dc adapters, open frame smps dip16 so16n table 1. device summary order codes package packaging L6599ATD so16n tube L6599ATDtr so16n tape and reel l6599atn dip16 tube www.st.com
contents l6599at 2/31 doc id 15534 rev 3 contents 1 device description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4.1 absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4.2 thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5 electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6 application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 6.1 oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 6.2 operation at no load or very light load . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6.3 soft-start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 6.4 current sense, ocp and olp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6.5 latched shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6.6 line sensing function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6.7 bootstrap section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 7 package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 8 revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
l6599at device description doc id 15534 rev 3 3/31 1 device description the l6599at is a temperature-extended version of the l6599a. it is a double-ended controller specifically designed for the series -resonant half-bridge topology. it provides a 50% complementary duty cycle: the high-side switch and the low-side switch are driven on/off at 180 out-of-phase for exactly the same time interval. output voltage regulation is obtained by modulating the operating frequency. a fixed dead-time inserted between the turn-off of one switch and the turn-on of the other guarantees soft-switching and enables high-frequency operation. to drive the high-side switch using the bootstrap approach, the ic incorporates a high- voltage floating structure capable of withstanding more than 600 v with a synchronous- driven high-voltage dmos that replaces the external fast-recovery bootstrap diode. the ic enables the designer to set the operating frequency range of the converter by means of an externally programmable oscillator. at start-up, to prevent uncontrolled inrush current, the switching frequency starts from a programmable maximum value and progressively decays until it reaches the steady-state value determined by the control loop. this frequency shift is non linear to minimize output voltage overshoots; its duration is programmable as well. at light load the ic may enter a controlled burst-mode operation that keeps the converter input consumption to a minimum. the device?s functions include a not-latched acti ve-low disable input with current hysteresis suitable for power sequencing or for brownout protection, a current sense input for ocp with frequency shift and delayed shutdown with automatic restart. a higher level ocp latches off the ic if the first-level protection is not sufficient to control the primary current. their combination offers complete protection against overload and short-circuits. an additional latched disable input (dis) allows easy implementation of otp and/or ovp. an interface with the pfc controller is provided that enables the switching off of the pre- regulator during fault conditions, such as ocp shutdown and dis high, or during burst- mode operation.
block diagram l6599at 4/31 doc id 15534 rev 3 2 block diagram figure 1. block diagram 9 f f 9 % 2 2 7 + 9 ' , 6 $ % / ( ' , 6 2 8 7 & % 2 2 7 / & |