SW

1

RON

2

VIN

3

BOOT

4

VCC

8

GND

7

DIM

6

CS

5

SW

1

RON

2

VIN

3

BOOT

4

VCC

8

GND

7

DIM

6

CS

5

DAP

LM3404, LM3404HV

SNVS465E – OCTOBER 2006 – REVISED FEBRUARY 2010

www.ti.com

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam

during storage or handling to prevent electrostatic damage to the MOS gates.

Connection Diagrams

Figure 1. 8-Lead Plastic SOIC-8 Package

Figure 2. 8-Lead Plastic So PowerPAD-8 Package

PIN DESCRIPTIONS

Pin(s)

Name

Description

Application Information

1

SW

Switch pin

Connect this pin to the output inductor and Schottky diode.

2

BOOT

MOSFET drive bootstrap pin

Connect a 10 nF ceramic capacitor from this pin to SW.

3

DIM

Connect a logic-level PWM signal to this pin to enable/disable the power

Input for PWM dimming

MOSFET and reduce the average light output of the LED array.

4

GND

Ground pin

Connect this pin to system ground.

5

CS

Set the current through the LED array by connecting a resistor from this pin to

Current sense feedback pin

ground.

6

RON

On-time control pin

A resistor connected from this pin to VIN sets the regulator controlled on-time.

7

VCC

Output of the internal 7V linear

Bypass this pin to ground with a minimum 0.1 µF ceramic capacitor with X5R or

regulator

X7R dielectric.

8

VIN

Nominal operating input range for this pin is 6V to 42V (LM3404) or 6V to 75V

Input voltage pin

(LM3404HV).

DAP

GND

Thermal Pad

Connect to ground. Place 4-6 vias from DAP to bottom layer ground plane.

2

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