power switch. RM3261S Datasheet
RM326X is a high performance off-line
PWM power switch for low power AC/DC
charger and adapter applications,It
operates in primary-side sensing and
TL431 could be eliminated, Proprietary
constant voltage and constant current
control is integrated as shown in the figure
In constant current control,the current
and output power setting can be adjusted
externally by the sense resistor RS at CS
pin,In constant voltage control,multi-mode
operations are utilized to achieve high
performance and high efficiency.In
addition,good load regulation is achieved
by the built-in cable drop compensation.
Device operates in PFM in CC mode as
well at large load condition and it operates
in PWM with frequency reduction at
RM326X offers power on soft start
control and protection coverage with
auto-recovery features including
Cycle-by-Cycle current limiting,VDD
OVP,VDD clamp and UVLO,Excellent EMI
perfoemance is achieved with proprietary
frequency shuffling technique.high
precision constant voltage and constant
current can be achieved by RM326X.
Otherwise,RM326X is offered in SOP8
and DIP-8 package.
±5% constant voltage regulation at
universal AC input.
High precision constant current
regulation at universal AC input.
Primary-side sensing and regulation
without TL431 and opto-coupler.
Programmable constant voltage and
constant current regulation.
Adjustable constant current and
output power setting.
Built-in secondary constant current
control with primary side feedback.
Built-in adaptive current peak
Built-in primary winding inductance
Programmable cable drop
Power on soft-start.
Built-in Leading Edge Blanking.
Cycle-by-Cycle current limiting.
VDD under voltage lockout with
VDD over voltage protect.
Low Power AC/DC off-line SMPS for
Cell phone charger
Digital cameras charger
Small power adapter
Auxiliary power for PC/TV etc.
P Power Supply
I Loop compensation for CV stability
The voltage feedback from auxiliary winding, connected
to resistor divider from auxiliary winding reflecting
output voltage,PWM duty cycle is determined by EA
output and current sense signal at PIN 4.
I Current sense input
HV MOSFET drain pin.the drain pin is connected to the
primary lead of the transformer