US1651 Datasheet, PDF (1/7 Pages) Unisonic Technologies – PRIMARY-SIDE REGULATION PWM POWER SWITCH

UNISONIC TECHNOLOGIES CO., LTD
US1651
Preliminary
PRIMARY-SIDE REGULATION
PWM POWER SWITCH
CMOS IC
 DESCRIPTION
The UTC US1651 is a primary control switch mode charger and
adapter applications. The controlled variable is transferred by an
auxiliary winding from the secondary to the primary side. The
device integrates PWM controller to enhance the performance of
discontinuous conduction mode (DCM) flyback converters.
The UTC US1651 operates in primary-side sensing and
regulation. Opto-coupler and TL431 could be eliminated. It
operates in fixed frequency mode at large load conditions,
frequency reduction mode at light/medium load and ‘Extended
burst mode’ at No/light load conditions. So that low standby power
can be achieved.
The UTC US1651 achieves high precision CV/CC regulation
and high power efficiency. It offers comprehensive protection
coverage with auto-recovery features including Cycle-by-cycle
current limiting, V_DD over voltage protection, V_DD clamp, OTP,
leading edge blanking, V_DD under voltage lockout, etc.
SOP-8
 FEATURES
* Programmable CV and CC regulation
* Primary-side sensing and regulation with No TL431 and
opto-coupler
* Multi-mode operation for high efficiency
* Adjustable constant current and output power setting
* Power on soft-start time (4ms)
* Frequency shuffling and adjustable gate drive greatly
improving EMI
* ”Extended burst mode control” for improved efficiency
and minimum standby design
* Built-in leading edge blanking (LEB)
* V_DD under voltage lockout
* V_DD over voltage shutdown and clamp
* Cycle-by-Cycle current limiting
* Fail-safe protection for open loop fault condition
* Auto-restart in over voltage condition
 ORDERING INFORMATION
Ordering Number
US1651G-S08-R
Package
SOP-8
Packing
Tape Reel
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