National Semiconductor LM3595 Technical data

LM3595
Parallel White-LED Driver

LM3595 Parallel White-LED Driver

August 2003

General Description

The LM3595 is a parallel white-LED driver that is capable of
driving four white LEDs. It can supply a total output current of
100mA over an input voltage range of 3.0V to 5.5V. The
amount of constant current sourced to the outputs is user
selectable using one external sense resistor.

LM3595 typically draws 0.03µA when placed in shutdown,
and 200µA when operating in the no-load condition. If any of
the outputs are not used, leave the pin(s) unconnected.

Brightness can be controlled by both analog and PWM tech­niques. A voltage between 0V and 3V may be applied to the
BRGT pin to vary the current. Output current will linearly
track the voltage applied to the BRGT pin. An active-low
level must be present on the BR-ON pin for analog bright­ness control to be disabled. Alternatively, a PWM signal can
be applied to the EN pin to vary the perceived brightness of
the LED.

The LM3595 uses an active-high enable level. The LM3595
is available in National’s LLP-10 package.

Typical Application Circuit

Features

n Regulated I

current outputs

n Drives one, two, three or four white LED’s with no bias

resistors

n 3.0V to 5.5V Input voltage
n Up to 100mA output current
n Active-High Enable Pin
n Analog Brightness Control
n Very small solution size
n LLP-10 package: 3.0mm x 3.0mm x 0.8mm
n Very Low Shutdown current (0.03µA typ.)

with±0.5% matching between constant

OUT

Applications

n Portable devices using white or blue LEDs with display

and backlight or frontlight

n Keypad LEDs
n Strobe LEDs

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Connection Diagram

LM3595

Pin Description

Pin Name Description

9V

1,2,3,4 OUT1-4 Current Source Outputs 1- 4 - Connect directly to LED’s

5

6

10

7

8, DAP GND Ground

LM3595

10-Pin Leadless Leadframe Package (LLP) - 3mm X 3mm

NS Package Number LDA10A

Input Voltage

Current Set Input- The resistor value tied between this pin and ground sets the
output current.

I

IN

SET

Active-High Enable Input-A1MΩ resistor is connected internally between this

EN

pin and GND to pull the voltage on this pin to 0V, and shut down the part,
when the pin is left floating.

BR-ON

Active-High Analog Brightness Control Enable - A voltage of .65 x V
applied to this pin to enable analog brightness control.

Analog-voltage-controlled Brightness Input - When the BR-ON pin is set high,

BRGT

the voltage on this pin allows analog control of the LED’s brightness. The
recommended voltage range on this pin is0-3Vwhere 3V is V
input impedance of this pin is 300kΩ.

IN

BR(MAX)

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must be

. The

Ordering Information

Order Number Package Number Package Marking Supplied as:

LM3595LD LDA10A L3595 1000 units on Tape-and-Reel

LM3595LDX LDA10A L3595 3500 units on Tape-and-Reel

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LM3595

Absolute Maximum Ratings (Notes 1,

2)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

V

IN

EN, BR-ON, BRGT -0.3V to

Junction Temperature (T

J-MAX-ABS

) 150˚C

Continuous Power Dissiation
(Note 3) Internally Limited

Storage Temperature Range -65˚C to 150˚C

−0.3V to 6.0V

+ 0.3V) w/

(V

IN

6.0V max

Operating Ratings (Notes 1, 2)

Input Voltage Range (Note 5) 3.0V to 5.5V

Output Voltage Range (Note 5) 2.0V to 5.5V

Junction Temperature Range
(Note 6) -40˚C to 105˚C

Ambient Temperature Range

-40˚C to 85˚C

(Note 6)

Thermal Information

Junction-to-Ambient Thermal
Resistance, LLP-10 Package (θ
(Note 7) 55˚C/W

)

JA

Lead Temperature
(Soldering, 5 Sec.) 260˚C

ESD Rating (Note 4)

Human-body model
Machine model

2kV

200V

Electrical Characteristics (Notes 2, 8)

Limits in standard typeface and typical values apply for TJ=25oC. Limits in boldface type apply over the operating junction
temperature range. Unless otherwise specified: V

= 5V, V

IN

Symbol Parameter Conditions Min Typ Max Units

≤ 5.5V

IN

≤ (VIN- 0.7V)

OUTX

= 4.99kΩ

≤ 5.5V

IN

≤ (VIN- 0.42V)

OUTX

= 8.25kΩ

≤ 5.5V

IN

≤ (VIN- 0.28V)

OUTX

= 12.4kΩ

=95%xI

OUT

= 4.99kΩ (I

=95%xI

OUT

= 12.4kΩ (I

= 0mA, V(BR-ON) = VIN,R

= 0mA, V(BR-ON) = VIN,R

I

OUTX

I

OUTX-BRGT

I

OUT-MATCH

V

SET

I

OUTX/ISET

V

HR

I

Q

3.0V ≤ V

2.0V ≤ V
R

SET

Output Current Regulation
(Note 5)

3.0V ≤ V

2.0V ≤ V
R

SET

3.0V ≤ V

2.0V ≤ V
R

SET

Analog Brightness Control
Current Regulation

V(BRGT) = 3.0V, V(BR-ON) = V

V(BRGT) = 0V, V(BR-ON) = V

Current Matching Between
Any Two Outputs

I

Pin Voltage 1.147

SET

Output Current to Current
Set Ratio

I

OUT

Current Source Headroom
Voltage (Note 5)

Quiescent Supply Current

R

SET

I

OUT

R

SET

I

OUTX

Open

I

OUTX

8.25kΩ

I

SD

V

EN-IH

V

EN-IL

V

BRON-IH

V

BRON-IL

Shutdown Supply Current EN = 0, V(BR-ON) = V

EN Input Logic High 3.0V ≤ VIN≤ 5.5V 1.2 V

EN Input Logic Low 3.0V ≤ VIN≤ 5.5V 0 .5 V

BR-ON Input Logic High 3.0V ≤ VIN≤ 5.5V .65xV

BR-ON Input Logic Low 3.0V ≤ VIN≤ 5.5V 0 .35xV

= 3.6V, R

OUTX

IN

IN

(nom)

(nom) approx. 25mA)

OUT

(nom)

(nom) approx. 10mA)

OUT

IN

= 8.25kΩ, V(EN) = VIN, V(BR-ON) = 0V

SET

22.54
(-8%)

13.80
(-8%)

9.20

(-8%)

13.83

(-6.5%)

24.5

15.0

10.0

14.8

100 250 µA

0.5 4 %

(-6%)

95

(-5%)

1.22

100

500 690

200 280

SET

SET

=

=

200 300 µA

350

0.03 1 µA

IN

26.46

(+8%)

16.20

(+8%)

10.80

(+8%)

15.77

(+6.5%)mA(%)

1.293

(+6%)

105

(+5%)

IN

V

IN

IN

mA

(%)

V

(%)

mV

V

V

V

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Electrical Characteristics (Notes 2, 8) (Continued)

Limits in standard typeface and typical values apply for TJ=25oC. Limits in boldface type apply over the operating junction

LM3595

temperature range. Unless otherwise specified: V

Symbol Parameter Conditions Min Typ Max Units

I

EN

I

BR-ON

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Operating Ratings are conditions under which operation
of the device is guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see
the Electrical Characteristics tables.

Note 2: All voltages are with respect to the potential at the GND pin.

Note 3: Thermal shutdown circuitry protects the device from permanent damage.

Note 4: The Human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin. The machine model is a 200pF capacitor discharged

directly into each pin. MIL-STD-883 3015.7

Note 5: The operation rating for minimum input voltage, V
must be satisfied for the desired output current to be realized. For more information, see the section on Output Current Capability found in this datasheet.

Note 6: In applications where high power dissipation and/or poor package thermal resistance is present, the maximum ambient temperature may have to be
derated. Maximum ambient temperature (T
dissipation of the device in the application (P
following equation: T

Note 7: Junction-to-ambient thermal resistance (θ
standard JESD51-7. The test board is a 4-layer FR-4 board measuring 102mm x 76mm x 1.6mm with a 2x1 array of thermal vias. The ground plane on the board
is 50mm x 50mm. Thickness of copper layers are 36µm/18µm/18µm/36µm (1.5oz/1oz/1oz/1.5oz). Ambient temperature in simulation is 22˚C, still air. Power
dissipation is 1W. The value of θ
and environmental conditions. In applications where high maximum power dissipation exists (high V
issues. For more information on these topics, please refer to Application Note 1187: Leadless Leadframe Package (LLP) and the Power Dissipation and PCB Layout
Considerations sections of this datasheet.

Note 8: All room temperature limits are 100% tested or guaranteed through statistical analysis. All limits at temperature extremes are guaranteed by correlation
using standard Statistical Quality Control methods (SQC). All limits are used to calculate Average Outgoing Quality Level (AOQL). Typical numbers are not
guaranteed, but do represent the most likely norm.

Note 9: The EN pin has an internally connected 1MΩ pull-down resistor

EN Pin Current (Note 9)

BR-ON Pin Current 0 ≤ V

A-MAX=TJ-MAX-OP

-(θJAxP

of the LM3595 in LLP-10 could fall in a range as wide as 50˚C/W to 150˚C/W (if not wider), depending on PWB material, layout,

JA

V(EN) = 1.5V 1.5

V(EN) = 0V 0

) is dependent on the maximum operating junction temperature (T

A-MAX

), and the junction-to ambient thermal resistance of the part/package in the application (θJA), as given by the

D-MAX

).

D-MAX

) is taken from a thermal modeling result, performed under the conditions and guidelines set forth in the JEDEC

JA

IN

BR-ON

, is limited by V

MIN

= 5V, V

≤ V

IN

OUTX

OUTX

= 3.6V, R

and I

OUTX

= 8.25kΩ, V(EN) = VIN, V(BR-ON) = 0V

SET

0µA

as dictated by headroom voltage. The equation, V

= 105˚C), the maximum power

J-MAX-OP

, high I

IN

), special care must be paid to thermal dissipation

OUT

MIN

≥ (V

OUTX+VHR

µA

),

Block Diagram

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