If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

V

IN

-0.3V to 6.0V

EN, PWM

-0.3V to (V

w/ 6.0V max

Continuous Power Dissipation

(Note 3)

Internally Limited

Junction Temperature

(T

150˚C

Storage Temperature Range

-65˚C to 150˚C

Lead Temp. (Soldering, 5 sec.)

260˚C

ESD Rating (Note 4)

Human Body Model

2kV

Input Voltage V

IN

3.0V to 5.5V

LED Voltage Range

2.5V to 3.9V

Junction Temperature Range (T

-40˚C to +115˚C

Ambient Temperature Range (T

(Note 5)

-40˚C to +85 ˚C

Thermal Information

Junction-to-Ambient Thermal Resistance,

LLP-14 Package (

θ

(Note 6)

45˚C/W

Electrical Characteristics

(Notes 2, 7)

Limits in standard typeface are for T

range (-40˚C to +85 ˚C). Unless otherwise noted, specifications apply to the LM27951 Typical Application Circuit (pg.1) with V

IN

= 3.6V, V(EN) = 1.8V, V(PWM) = 1.8V, 4 LEDs, V

Ω (Note 8)

Symbol

Parameter

Conditions

Min

Typ

Max

Units

I

DX

LED Current Regulation

3.0V

≤ V

IN

≤ 5.5V

R

Ω

I

18.4

(−8%)

20

21.6

(+8%)

mA

3.0V

≤ V

IN

≤ 5.5V

R

Ω

I

30

3.0V

≤ V

IN

≤ 5.5V

R

Ω

I

10

I

D-MATCH

LED Current Matching

(Note 9)

R

Ω

0.2

1.5

%

I

Q

Quiescent Supply Current

D

R

1.5

1.9

mA

I

SD

Shutdown Supply Current

3.0V

≤ V

IN

≤ 5.5V

V(EN) = 0V

0.1

1

µA

V

SET

I

3.0V

≤ V

IN

≤ 5.5V

1.25

V

I

Output Current to Current

Set Ratio

200

V

HR

Current Source Voltage

Headroom Requirement

(Note 10)

I

R

Ω

(I

360

mV

I

R

Ω

(I

240

f

SW

Switching Frequency

525

(-30%)

750

975

(+30%)

kHz

V

IH

Logic Input High

Input Pins: EN, PWM

3.0V

≤ V

IN

≤ 5.5V

1.0

V

IN

V

V

IL

Logic Input Low

Input Pins: EN, PWM

3.0V

≤ V

IN

≤ 5.5V

0

0.4

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