L6591:Current mode PWM controller for Asymmetrical Half Bridge converter topology

The L6591 is a double-ended PWM controller specific to the soft-switched half bridge topology. It provides complementary PWM control, where the high-side switch is driven ON for a duty cycle D and the low-side switch for a duty cycle 1-D, with D < 50%. An externally programmable deadtime inserted between the turn-off of one switch and the turn-on of the other one guarantees soft-switching and enables high-frequency operation.

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 of the converter by means of an externally programmable oscillator: the maximum duty cycle is digitally clipped at 50% by a T-flip-flop, so that the operating frequency is half that of the oscillator.

At very light load the IC enters a controlled burst mode operation that, along with the built-in non-dissipative high-voltage startup circuit and the low quiescent current, helps keep the consumption from the mains low and is compliant with energy saving recommendations.

To allow compliance with these standards also in two-stage power-factor-corrected systems, an interface with the PFC controller is provided that enables the pre-regulator to be switched off between one burst and the following one.

An innovative adaptive UVLO helps minimize the issues related to fluctuations of the self-supply voltage with the output load, due to the transformer's parasitic.

IC protection functions include: not-latched input undervoltage (brownout), a first-level OCP with delayed shutdown able to protect the system during overload and short-circuit conditions (either auto-restart or latch mode can be selected) and a second-level OCP that latches off the IC when the transformer saturates or one of the secondary diodes fails short. Finally, a latched disable function allows easy implementation of OTP or OVP.

Programmable soft-start and digital leading-edge blanking on the current sense input pin complete the equipment of the IC.

Key Features

  • Complementary PWM control for soft-switched half bridge with programmable deadtime
  • Up to 500 kHz operating frequency
  • Onboard high-voltage startup
  • Advanced light load management
  • Adaptive UVLO
  • Pulse-by-pulse OCP
  • OLP (latched or autorestart)
  • Transformer saturation detection
  • Interface with PFC controller
  • Latched disable input
  • Input for power-on sequencing or brownout protection
  • Programmable soft-start
  • 4% precision external reference
  • 600 V-rail compatible high-side gate driver with integrated bootstrap diode and high dV/dt immunity
  • SO16N package
Product Specifications
DescriptionVersionSize
DS5866: PWM controller for ZVS half bridge6.01 MB
Application Notes
DescriptionVersionSize
AN2852: EVL6591-90WADP: 90 W AC-DC asymmetrical half-bridge adapter using L6591 and L65631.11 MB
Presentations
DescriptionVersionSize
Primary side regulation controllers portfolio1 MB
Flyers
DescriptionVersionSize
High-efficiency ATX design using asymmetrical half-bridge topology2.11 MB
Brochures
DescriptionVersionSize
Brochure Power management guide05.20164 MB
Solution Evaluation Tools
Part NumberManufacturerDescription
EVL6591-90WADP90W ac-dc asymmetrical half bridge adapter using L6591 and L6563
Sample & Buy
Part NumberPackagePacking TypeUnit Price (US$) *QuantityECCN (EU)ECCN (US)Country of Origin
L6591TRSO-16Tape And Reel--NECEAR99CHINA
L6591SO-16Tube--NECEAR99CHINA
Quality & Reliability
Part NumberPackageGradeRoHS Compliance GradeMaterial Declaration**
L6591TRSO-16IndustrialEcopack2md_q7-wspc-so-wspc-16-wspc-.15-wspc-to-wspc-jedec-wspc-ms-012_c5q7-wspc-mu62bbx.pdf
md_q7-wspc-so-wspc-16-wspc-.xml
L6591SO-16IndustrialEcopack2md_q7-wspc-so-wspc-16-wspc-.15-wspc-to-wspc-jedec-wspc-ms-012_c5q7-wspc-mu62bbx.pdf
md_q7-wspc-so-wspc-16-wspc-.xml
PWM controller for ZVS half bridge L6591
circuit_diagram_14821_thumbnail.png L6591
EVL6591-90WADP: 90 W AC-DC asymmetrical half-bridge adapter using L6591 and L6563 EVL6591-90WADP
48 V - 130 W high efficiency converter with PFC for LED street lighting applications - European version L6599AT
10W off-line LED driver based on VIPER27 VIPER27
Very low drop voltage regulators with inhibit KFXX
md_q7-wspc-so-wspc-16-wspc-.15-wspc-to-wspc-jedec-wspc-ms-012_c5q7-wspc-mu62bbx.pdf L6591
md_q7-wspc-so-wspc-16-wspc-.xml HCF4060