LM3445-220VEVAL National Semiconductor, LM3445-220VEVAL Datasheet - Page 2

• Manufacturer Part Number: LM3445-220VEVAL
• Description: LM3445 Triac Dimmable Offline LED Driver; Qty per Container: 1/
• Manufacturer: National Semiconductor

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Pin #
Order Number
Connection Diagram
Ordering Information
LM3445MMX
Pin Descriptions
10
LM3445MM
1
2
3
4
5
6
7
8
9
FLTR1
FLTR2
Name
ASNS
COFF
GATE
BLDR
GND
ISNS
DIM
V
CC
NOPB
NOPB
Spec.
Description
PWM output of the triac dim decoder circuit. Outputs a 0 to 4V PWM signal with a duty cycle proportional to
the triac dimmer on-time.
First filter input. The 120Hz PWM signal from ASNS is filtered to a DC signal and compared to a 1 to 3V, 5.85
kHz ramp to generate a higher frequency PWM signal with a duty cycle proportional to the triac dimmer firing
angle. Pull above 4.9V (typical) to tri-state DIM.
Input/output dual function dim pin. This pin can be driven with an external PWM signal to dim the LEDs. It may
also be used as an output signal and connected to the DIM pin of other LM3445 or LED drivers to dim multiple
LED circuits simultaneously.
OFF time setting pin. A user set current and capacitor connected from the output to this pin sets the constant
OFF time of the switching controller.
Second filter input. A capacitor tied to this pin filters the PWM dimming signal to supply a DC voltage to control
the LED current. Could also be used as an analog dimming input.
Circuit ground connection.
LED current sense pin. Connect a resistor from main switching MOSFET source, ISNS to GND to set the
maximum LED current.
Power MOSFET driver pin. This output provides the gate drive for the power switching MOSFET of the buck
controller.
Input voltage pin. This pin provides the power for the internal control circuitry and gate driver.
Bleeder pin. Provides the input signal to the angle detect circuitry as well as a current path through a switched
230Ω resistor to ensure proper firing of the triac dimmer.
MSOP-10
MSOP-10
Package
Type
NSC Package
Drawing
MUB10A
MUB10A
NS Package Number MUB10A
10-Pin MSOP
Top View
2
Top Mark
SULB
SULB
30060303
1000 Units, Tape and Reel
3500 Units, Tape and Reel
Supplied As