LTC3454

11

3454fa

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-

tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.

LED Failure Modes

If the LED fails as an open circuit, the safety amplifier takes

The safety amplifier has no effect on loop regulation at

If the LED fails as a short-circuit, the current limiting

circuitry detects this condition and limits the peak input

current to a safe level.

Figure 3. Brightness Control Methods: (a) Using Voltage DAC, (b) Using Current DAC, (c) Using Potentiometer, (d) Using PWM Input

LED

LTC3454

(3d)

100

3454 F03

ENx

= 3850

LED

LTC3454

(3c)

ENx

0.8V

LED

LTC3454

(3b)

ENx

IDAC ≤

0.8V

(3a)

CURRENT

DAC

LED

LTC3454

ENx

VOLTAGE

DAC

DD Package

10-Lead Plastic DFN (3mm

× 3mm)

(Reference LTC DWG # 05-08-1699)

APPLICATIONS INFORMATION

PACKAGE DESCRIPTION

3.00 0.10

(4 SIDES)

NOTE:

1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-2).

CHECK THE LTC WEBSITE DATA SHEET FOR CURRENT STATUS OF VARIATION ASSIGNMENT

2. DRAWING NOT TO SCALE

3. ALL DIMENSIONS ARE IN MILLIMETERS

4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE

MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE

5. EXPOSED PAD SHALL BE SOLDER PLATED

6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE

TOP AND BOTTOM OF PACKAGE

0.38

0.10

BOTTOM VIEW—EXPOSED PAD

1.65

0.10

(2 SIDES)

0.75 0.05

R = 0.115

TYP

2.38 0.10

(2 SIDES)

1

5

10

6

PIN 1

TOP MARK

(SEE NOTE 6)

0.200 REF

0.00 – 0.05

(DD) DFN 1103

0.25

0.05

2.38 0.05

(2 SIDES)

RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS

1.65 0.05

(2 SIDES)

2.15 0.05

0.50

BSC

0.675 0.05

3.50 0.05

PACKAGE

OUTLINE

0.25

0.05

0.50 BSC