Diodes AL5801 User Manual

A

L5801

100V, ADJUSTABLE CURRENT SINK LINEAR LED DRIVER

EXT

Pin Assignments

Applications

• Linear LED Drivers

• LED Signs

• Offline LED Luminaries

(Top View)

SOT26

Description

The AL5801 combines a 100V N-channel MOSFET with a prebiased NPN transistor to make a simple, small footprint LED driver.

The LED current is set by an external resistor connected from R pin (4) to GND pin (6). The internal pre-biased transistor develops approximately 0.56V across the external resistor.

The AL5801 open-drain output can operate from 1.1V to 100V enabling it to operate 5V to 100V power supplies without additional components.

PWM dimming of the LED current can be achieved by driving the BIAS pin (1) with an external, open-collector NPN transistor or open-drain N-channel MOSFET.

The AL5801 is available in a SOT26 package and is ideal for driving LED currents up to 350mA.

Features

• Feedback Pin Reference Voltage V

• -40°C to +125°C Temperature Range

• 1.1V to 100V Open-Drain Output

• Negative temperature V

the LED current at high temperatures

• Low thermal impedance SOT26 package with copper lead frame

• Lead-Free Finish; RoHS Compliant (Notes 1 & 2)

• Halogen and Antimony Free. “Green” Device (Note 3)

• Qualified to AEC-Q101 Standards for High Reliability

Notes: 1. EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. All applicable RoHS exemptions applied.

2. See http://www.diodes.com for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and Lead-free.

3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and <1000ppm antimony compounds.

co-efficient automatically reduces

RSET

= 0.56V at +25°C

RSET

Typical Applications Circuit

AL5801

Document number: DS35555 Rev. 3 - 2

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Pin Descriptions

Number

1 BIAS Biases the open-Drain output MOSFET 2 FB Feedback pin 3 OUT Open-Drain LED driver output 4 R

5 COMP 6 GND Ground refe rence point for setting the LED current

Name

Current sense pin. LED current sensing resistor should be connected from here to GND

EXT

Compensation pin. Connect COMP pin to REXT pin and insert a 1nF ceramic capacitor from COMP pin to FB pin for improved transient stability

Functional Block Diagram

L5801

Function

Figure 1 Block Diagram

Absolute Maximum Ratings (@T

Symbol Characteristics Values Unit

V

OUT

V

BIAS

VFB

V

COMP

V

REXT

I

OUT

TJ

TST

Note: 4. With pins 5 and 6 connected together.

These are stress ratings only. Operation outside the absolute maximum ratings may cause device failure. Operation at the absolute maximum rating for extended periods may reduce device reliability.

Output voltage relative to GND 100 V BIAS voltage relative to GND (Note 4) 20 V FB voltage relative to GND 6 V COMP voltage relative to GND 6 V REXT voltage relative to GND 6 V Output current 350 mA Operating junction temperature -40 to +150 °C Storage temperature -55 to +150 °C

= +25°C, unless otherwise specified.)

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AL5801

Document number: DS35555 Rev. 3 - 2

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L5801

Package Thermal Data

Characteristic Symbol Value Unit

Power Dissipation (Note 5) @ TA = +25°C Power Dissipation (Note 6) @ TA = +25°C Power Dissipation (Note 7) @ TA = +25°C Power Dissipation (Note 8) @ TA = +25°C Thermal Resistance, Junction to Ambient Air (Note 5) @ TA = +25°C Thermal Resistance, Junction to Ambient Air (Note 6) @ TA = +25°C Thermal Resistance, Junction to Ambient Air (Note 7) @ TA = +25°C Thermal Resistance, Junction to Ambient Air (Note 8) @ TA = +25°C

Notes: 5. Device mounted on 15mm x 15mm 2oz copper board.

6. Device mounted on 25mm x 25mm 1oz copper board.

7. Device mounted on 25mm x 25mm 2oz copper board.

8. Device mounted on 50mm x 50mm 2oz copper board.

P

D

R

JA

θ

0.75

0.70

0.85

1.05 165 180 145 120

W

°C/W

Recommended Operating Conditions (@T

= +25°C, unless otherwise specified.)

A

Symbol Parameter Min Max Unit

V

BIAS

V

OUT

I

LED

TA

Note: 9. Subject to ambient temperature, power dissipation and PCB.

NMOSFET Electrical Characteristics: (Q1) (@T

OFF CHARACTERISTICS

Drain-Source Breakdown Voltage Zero Gate Voltage Drain Current Gate-Source Leakage

ON CHARACTERISTICS

Gate Threshold Voltage Static Drain-Source On-Resistance Forward Transconductance

Diode Forward Voltage

DYNAMIC CHARACTERISTICS

Input Capacitance Output Capacitance Reverse Transfer Capacitance

AL5801

Document number: DS35555 Rev. 3 - 2

Supply voltage range 3.5 20 OUT voltage range 1.1 100

V

LED pin current (Note 9) 25 350 mA Operating ambient temperature range -40 125 °C

= +25°C, unless otherwise specified.)

A

Characteristic Symbol Min Typ Max Unit Test Condition

BV

DSS

I

DSS

I

⎯ ⎯

GSS

V

GS(th)

R

⎯

DS (ON)

g

⎯

fs

V

SD

C

⎯

iss

C

⎯

oss

C

rss

100

⎯ ⎯

2.0

⎯

0.89 1.1 V

⎯

⎯ ⎯

±100

⎯

0.85

0.99

0.9

129

14

8

1 µA

4.1 V

⎯

⎯ ⎯ ⎯

V

GS

V

DS

nA

V

GS

V

DS

V

GS

Ω

V

GS

S

V

DS

VGS = 0V, IS = 1.5A

pF

V

pF pF

DS

f = 1.0MHz

= 0V, ID = 250µA = 60V, VGS = 0V

= ±20V, VDS = 0V

= VGS, ID = 250µA

= 10V, ID = 1.5A = 6V, ID = 1A

= 15V, ID = 1A

= 50V, VGS = 0V

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M

A

P

OWER D

PATIO

N

M

P

OWER D

PATIO

N

U

NCTIO

N T

O

N

T

R

Pre-Bias Transistor Electrical Characteristics: (Q2) (@T

Characteristic (Note 10) Symbol Min Typ Max Unit Test Condition

V

Input Voltage Output Voltage

Output Current DC Current Gain Input Resistance Resistance Ratio

Notes: 10. Short duration pulse test used to minimize self-heating effect.

V

I

R

I(off) I(on)

O(on)

O(off)

G

R

1

2/R1

1

0.4 - - V

- - 1.5 V

- 0.05 0.3 V

- - 0.5

80 - - -

3.2 4.7 6.2 kΩ 8 10 12 - -

Thermal Characteristics

1.2

= +25°C, unless otherwise specified.)

A

VCC = 5V, IO = 100μA VCC = 0.3V, IO = 5mA IO/II = 5mA/0.25mA

μA

VCC = 50V, VI = 0V VO = 5V, IO = 10mA

L5801

1.0

(W)

ISSI

0.8

0.6

50mm x 50mm

(2oz. FR4)

25mm x 25mm

(2oz. FR4)

15mm x 15mm

(2oz. FR4)

0.4

X

0.2

0

0 25 50 75 100 125 150

TEMPERATURE (°C)

Figur e 2 Derating Cur ve

180 160

140

T = 25°C

A

25mm x 25mm 1oz. FR4

AI

120

100

AMBIE

D = 0.5

80

60

D = 0.2

T = 25°C

A

2oz. FR4

1.0

(W)

0.8

ISSI

0.6

0.4

AX

0.2

0

0 500 1,000 1,500 2,000 2,500

COPPER AREA (mm )

D = 0.1

D = 0.05

Figur e 3 Area vs. Max Power

2

J

40

THERMAL RESISTANCE (°C/W)

Single Pulse

20

0

0.0001 0.001 0.01 0.1 1 10 100 1,000 PULSE WIDTH (s)

Figure 4 Tran si ent Therm al Impedance

AL5801

Document number: DS35555 Rev. 3 - 2

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