LM5026_15 Datasheet, PDF (1/39 Pages) Texas Instruments – LM5026 Active Clamp Current Mode PWM Controller

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LM5026
SNVS363E – AUGUST 2005 – REVISED NOVEMBER 2015
LM5026 Active Clamp Current Mode PWM Controller
1 Features
•1 Current-Mode Control
• Internal 100-V Start-Up Bias Regulator
• 3-A Compound Main Gate Driver
• High Bandwidth Optocoupler Interface
• Programmable Line Undervoltage Lockout (UVLO)
With Adjustable Hysteresis
• Versatile Dual Mode Overcurrent Protection With
Hiccup Delay Timer
• Programmable Overlap or Deadtime between the
Main and Active Clamp Outputs
• Programmable Maximum Duty Cycle Clamp
• Programmable Soft-Start
• Leading Edge Blanking
• Resistor Programmed 1-MHz Capable Oscillator
• Oscillator Sync I/O Capability
• Precision 5-V Reference
2 Applications
• Server Power Supplies
• 48-V Telecom Power Supplies
• High Efficiency DC–DC Power Supplies
3 Description
The LM5026 PWM controller contains all of the
features necessary to implement power converters
utilizing the active clamp and reset technique with
current-mode control. With the active clamp
technique, higher efficiencies and greater power
densities can be realized compared to conventional
catch winding or RDC clamp and reset techniques.
Two control outputs are provided, the main power
switch control (OUT_A) and the active clamp switch
control (OUT_B). The device can be configured to
control either a P-Channel or N-Channel clamp
switch. The main gate driver features a compound
configuration, consisting of both MOS and Bipolar
devices, providing superior gate drive characteristics.
The LM5026 can be configured to operate with bias
voltages over a wide input range of 8 V to 100 V.
Additional features include programmable maximum
duty cycle, line undervoltage lockout, cycle-by-cycle
current limit, hiccup mode fault operation with
adjustable timeout delay, PWM slope compensation,
soft-start, 1-MHz capable oscillator with
synchronization input and output capability, precision
reference, and thermal shutdown.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
LM5026
WSON (16)
TSSOP (16)
5.00 mm × 5.00 mm
4.40 mm × 5.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Typical Application Circuit
V_IN
36 - 78V
V_OUT
3.3V
T1
CS
V_CC
V_IN
LM5026
CS
UVLO _{OUT_A}
TIME
RES
RT
OUT_B
REF
COMP
DCL
SYNC
SS
PGND AGND
SYNC I/O
ERROR
AMP and
ISOLATION
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.