STMicroelectronics 19V - 90W Adapter with PFC for Laptop computers using the L6563H and L6699 EVL6699-90WADP EVL6699-90WADP Ficha De Dados

Códigos do produto
EVL6699-90WADP
Página de 38
Description
L6699
4/38
Doc ID 022835 Rev 2
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-
phase for exactly the same time. Output voltage regulation is obtained by modulating the 
operating frequency. The deadtime inserted between the turn-off of one switch and the turn-
on of the other one is automatically adjusted to best fit the transition times of the half bridge 
midpoint. To drive the high-side switch with the bootstrap approach, the IC incorporates a 
high voltage floating structure able to withstand more than 600 V with a synchronous-driven 
high voltage DMOS that replaces the external fast-recovery bootstrap diode. 
The IC enables the user to set the operating frequency range of the converter by means of a 
high-accuracy externally programmable oscillator. 
At startup, in addition to the traditional frequency-shift soft-start (the switching frequency 
starts from a preset maximum value and then decays as far as the steady-state value 
determined by the control loop), a proprietary circuit controls the half bridge to prevent hard-
switching from occurring in the initial cycles because of the unbalance in the V·s applied to 
the transformer. 
At light load the IC can be forced to enter a controlled burst-mode operation that keeps the 
converter input consumption as low as possible. 
IC protection functions include a current sense input for OCP with frequency shift and 
delayed shutdown with automatic restart. Fast shutdown with automatic restart occurs if this 
first-level protection cannot control the primary current. Additionally, the IC prevents the 
converter from working in or too close to the capacitive mode, to guarantee soft-switching. A 
latched disable input (DIS) can be used to implement OTP and/or OVP. The combination of 
these protection features offers the highest degree of safety.
Other functions include a not-latched active-low disable input with current hysteresis, useful 
for power sequencing or for brownout protection, and an interface with the PFC controller 
that enables the switching-off of the pre-regulator during fault conditions or during burst-
mode operation.