Connection Diagrams

Top View

30060303

10-Pin MSOP

NS Package Number MUB10A

Top View

30060373

14-Pin SOIC

NS Package Number M14A

Ordering Information

Order Number

Spec.

Package Type

NSC Package

Drawing

Top Mark

Supplied As

LM3445MM

NOPB

MSOP-10

MUB10A

SULB

1000 Units, Tape and Reel

LM3445MMX

NOPB

MSOP-10

MUB10A

SULB

3500 Units, Tape and Reel

LM3445M

NOPB

SOIC-14L

M14A

LM3445M

55 Units, Rail

LM3445MX

NOPB

SOIC-14L

M14A

LM3445M

2500 Units, Tape and Reel

Pin Descriptions

SOIC

MSOP

Name

Description

12

1

ASNS

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.

13

2

FLTR1

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.

14

3

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 LM3445s or

other LED drivers to dim multiple LED circuits simultaneously.

1

4

COFF

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.

3

5

FLTR2

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.

4

6

GND

Circuit ground connection.

7

7

ISNS

LED current sense pin. Connect a resistor from main switching MOSFET source, ISNS to GND to

set the maximum LED current.

8

8

GATE

Power MOSFET driver pin. This output provides the gate drive for the power switching MOSFET

of the buck controller.

9

9

V

CC

Input voltage pin. This pin provides the power for the internal control circuitry and gate driver.

10

10

BLDR

Bleeder pin. Provides the input signal to the angle detect circuitry as well as a current path through

a switched 230

Ω resistor to ensure proper firing of the triac dimmer.

2,5,6,11

-

N/C

No Connect

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