PFS757HG POWERINT [Power Integrations, Inc.], PFS757HG Datasheet - Page 3

• Manufacturer Part Number: PFS757HG
• Description: Combined Two-Switch Forward and Flyback Power Supply Controllers with Integrated High Voltage MOSFETs
• Manufacturer: POWERINT [Power Integrations, Inc.]

Description
The HiperTFS device family members incorporate both a
high-power two-switch-forward converter and a mid-power
flyback (standby) converter into a single, low-profile eSIP™
power package. The single chip solution provides the controllers
for the two-switch-forward and flyback converters, high- and
low-side drivers, all three of the high-voltage power MOSFETs,
and eliminates the converter’s need for costly external pulse
transformers. The device is ideal for high power applications
that require both a main power converter (two-switch forward)
up to 414 W, and standby converter (flyback) up to 20 W.
HiperTFS includes Power Integrations’ standard set of comprehen-
sive protection features, such as integrated soft-start, fault and
over-load protection, and hysteretic thermal shutdown.
HiperTFS utilizes advanced power packaging technology that
simplifies the complexity of two-switch forward layout, mounting
and thermal management, while providing very high power
capabilities in a single compact package. The devices operate
over a wide input voltage range, and can be used following a
power-factor correction stage such as HiperPFS.
Two-switch-forward power converters are often selected for
applications demanding cost-effective efficiency, fast transient
response, and accurate tolerance to line voltage fluctuation. The
two-switch-forward controller incorporated into HiperTFS
devices improves on the classic topology by allowing operation
considerably above 60% duty cycle. This improvement reduces
RMS currents conduction losses, minimizes the size and cost of
the bulk capacitor, and minimizes output diode voltage ratings.
The advanced design also includes transformer flux reset
control (saturation protection) and charge-recovery switching of
the high-side MOSFET, which reduces switching losses. This
combination of innovations yields an extremely efficient power
supply with smaller MOSFETs, fewer passives and discrete
components, and a lower-cost transformer.
HiperTFS’s flyback standby controller and MOSFET solution is
based on the highly popular TinySwitch™ technology used in
billions of power converter ICs due to its simplicity of operation,
light load efficiency, and rugged, reliable, performance. This
flyback converter can provide up to 20 W of output power and
the built in overload power compensation reduces component
design margin.
Product Highlights
Protected Two-Switch Forward and
Flyback Combination Solution
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www.powerint.com
Incorporates three high-voltage power MOSFETs, main and
standby controllers, and gate drivers
Level shift technology eliminates need for pulse transformer
Programmable line undervoltage (UV) detection prevents
turn-off glitches
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Asymmetrical Two-Switch Forward Reduces Losses
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20 W Flyback with Selectable Power Limit
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Advanced Package for High Power Applications
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Programmable line overvoltage (OV) detection; latching and
non-latching
Accurate hysteretic thermal shutdown (OTP)
Accurate selectable current limit (main and standby)
Fully integrated soft-start for minimum start-up stress
Simple fast AC reset
Reduced EMI
Eliminates up to 30 discrete components for higher reliability
and lower cost
Allows >50% duty cycle operation
Transformer reset control
Duty cycle soft-start with 115% current limit boost
Output short circuit protection (SCP) with auto-restart
Remote ON/OFF function
Voltage mode controller with current limit
TinySwitch-III based converter
Selectable power limit (10 W, 12.5 W, 15 W, or 20 W)
Built-in overload power compensation
Output overvoltage (OV) protection with fast AC reset
Auto-restart
434 W output power capability in a highly compact package
Simple clip mounting to heat sink
Staggered pin arrangement for simple routing of board traces
and high-voltage creepage requirements
Single power package for two power converters reduces
assembly costs layout size
Can be directly connected to heat sink without insulation pad
Provides thermal impedance equivalent to a TO-220
Heat slug connected to ground potential for low EMI
Latching, non-latching, or auto-restart
Up to 550 W peak
Satisfies 2 ms ~ 20 ms start-up with large capacitance at
output
Flat overload power vs. input voltage
Reduces component stress during overload conditions
Reduces required design margin for transformer and output
diode
Output over-current protection (OCP)
Synchronized 66 kHz forward and 132 kHz flyback
converters
Frequency jitter
Reduces primary side RMS currents and conduction losses
Minimizes the size and cost of the bulk capacitor
Allows reduced capacitance or longer hold-up time
Allows lower voltage output diodes
Prevents transformer saturation under all conditions
Extends duty cycle to satisfy AC cycle drop out ride through
TFS757-764HG
Rev. C 02/11
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