Enhanced high-voltage resonant controller

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.

Key Features

  • Symmetrical duty cycle, variable frequency control of resonant half bridge
  • Self-adjusting adaptive deadtime
  • High-accuracy oscillator
  • 2-level OCP: frequency-shift and immediate shutdown
  • Interface with PFC controller
  • Anti-capacitive-mode protection
  • Burst-mode operation at light load
  • Input for brownout protection or power-on/off sequencing
  • “Safe-start” procedure prevents hard switching at startup
  • 600 V rail compatible high-side gate driver with integrated bootstrap diode and high dv/dt immunity
  • -300/800 mA high-side and low-side gate drivers with UVLO pull-down
  • SO16N package



Description Version Size
DS8908 DS8908: Enhanced high voltage resonant controller 2.0 954 KB
Description Version Size
AN4677 AN4677: 12 V - 150 W resonant converter with synchronous rectification based on L6563H, L6699 and SRK2001 1.0 3 MB
AN4027 AN4027: 12 V - 150 W resonant converter with synchronous rectification using the L6563H, L6699 and SRK2000A 3.0 2 MB
AN4026 AN4026: 19 V - 90 W adapter with PFC for laptop computers using the L6563H and L6699 1.2 988 KB
AN4720 AN4720: Half bridge resonant LLC converters and primary side MOSFET selection 1.0 1 MB
AN4599 AN4599: STEVAL-ISA132V1 24 V 300 W peak power resonant converter 3.0 904 KB
Design Notes & Tips
Description Version Size
DT0009 DT0009: Speed up development of the L6699 with the L6599A and flexible PCB layout 1.1 262 KB

HW Model, CAD Libraries & SVD

HW Model, CAD Libraries & SVD
Description Version Size
L6699 ORCAD macromodel 1.0 94 KB
L6699 SIMPLIS MAROTTA encrypted 1.0 194 KB


Description Version Size
EuP Lot 6 Tier2 Ecodesign requirements for Standby 2 MB
L6699: Double-ended controller specific to series-resonant half-bridge topology 2.0 430 KB
Primary side regulation controllers portfolio 1 MB


Description Version Size
Brochure Power management guide 09.2017 4 MB




型号 Package Packing Type Marketing Status Unit Price (US$) * Quantity ECCN (EU) ECCN (US) Country of Origin More info Order from ST Order from Distributors
L6699DTR SO-16 Tape And Reel Active 0.919 1000 NEC EAR99 CHINA MORE INFO 获取样片 Add to cart DISTRIBUTOR AVAILABILITY

(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office  or our Distributors


型号 Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
L6699D ActiveSO-16IndustrialEcopack2 0 0
L6699DTR ActiveSO-16IndustrialEcopack2 0 0

(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.