Diodes AL5802 User Manual

L5802

Description

The AL5802 combines a high gain NPN transistor with a pre-biased NPN transistor to make a simple small footprint LED driver.

The LED current is set by an external resistor connected from REXT pin (6) to GND pin (4), the internal high gain transistor develops approximately 0.6V across the external resistor.

The AL5802 open-collector output can operate from 0.8V to 30V enabling it to operate from 5V to 24V power supplies without additional components.

PWM dimming of the LED current can be achieved by either driving

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the BIAS pin (2) with a low impedance voltage source, or driving the EN pin (3) with an external open-collector NPN transistor or opendrain N-channel MOSFET.

The AL5802 is available in a SOT26 package and is ideal for driving 20mA to 120mA LED currents.

Features

ADVANCE INFORMATION

 Reference voltage VRSET = 0.65V

 -40 to +125°C temperature range

 0.8V to 30V open-collector output

 Negative temperature co-efficient – automatically reduces the

LED current at high temperatures

 Low thermal impedance SOT26 with copper leadframe

 Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)

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

 Qualified to AEC-Q101 Standards for High Reliability

30V, ADJUSTABLE CURRENT SINK LINEAR LED DRIVER

Pin Assignments

(Top View)

654

123

SOT26

Applications

 Linear LED driver

 LED signs

 Offline LED luminaries

Typical Application Circuit

Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.

2. See http://www.diodes.com/quality/lead_free.html 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.

AL5802

Document number: DS35516 Rev. 9 - 2

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Pin Descriptions

Pin Number Name Function

1 OUT Open-collector LED driver output 2 BIAS Biases the open collector output transistor 3 EN Enable pin for PWM dimming. Provides access to the base of Q2 and collector of Q1 4 GND Ground reference point for setting LED current

5 FB

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

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Functional Block Diagram

ADVANCE INFORMATION

L5802

Feedback pin. Should be connected to pin 6.

Fig. 1 Block Diagram

Absolute Maximum Ratings

Symbol Characteristics Values Unit

OUT

BIAS

REXT

OUT

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.

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

AL5802

Document number: DS35516 Rev. 9 - 2

Output voltage relative to GND BIAS voltage relative to GND (Note 4) LED voltage relative to GND EN voltage relative to GND REXT voltage relative to GND Output current Operating junction temperature Storage temperature

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30 V 30 V

6 V 6 V 6 V

150 mA

-40 to +150 °C

-55 to +150 °C

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(BR)

)

(BR)

)

L5802

Package Thermal Data

Characteristic Symbol Value Unit

Power Dissipation (Note 5) @ TA = +25°C Power Dissipation (Note 6) @ T Power Dissipation (Note 7) @ T

= +25°C

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

Notes: 5. Device mounted on FR-4 PCB, 2oz with minimum recommended pad layout.

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

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

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= +25°C

θJA

0.37

0.87 1

335 143 120

°C/W

Recommended Operating Conditions

Symbol Parameter Min Max Unit

BIAS

ADVANCE INFORMATION

OUT

LED

Note: 8. Subject to ambient temperature, power dissipation and PCB.

Electrical Characteristics – NPN Transistor – Q1 (@T

Symbol Characteristic Test Condition Min Typ Max Unit

V V

CE(SAT

BE(SAT

CEX

IBL

hFE

Collector-Emitter Breakdown Voltage (Note 9)

CEO

Emitter-Base Breakdown Voltage

EBO

Collector Cutoff Current Base Cutoff Current

DC Current Gain

Collector-Emitter Saturation Voltage (Note 9) Base-Emitter Saturation Voltage

Electrical Characteristics – NPN Pre-biased Transistor – Q2 (@T

Symbol Characteristic Test Condition Min Typ Max Unit

V V V

CBO

EBO

CE(SAT

hFE

*Characteristics of transistor only.

Note: 9. Short duration pulse test used to minimize self-heating effect.

AL5802

Document number: DS35516 Rev. 9 - 2

Collector-Base Breakdown Voltage

CBO

Collector-Emitter Breakdown Voltage (Note 9)

CEO

Emitter-Base Breakdown Voltage

EBO

Collector Cut-Off Current Emitter Cut-Off Current Collector-Emitter Saturation Voltage (Note 9) DC Current Gain (Note 9) Input Resistance — 7 10 13 kΩ

Supply voltage range 4.5 30 OUT voltage range 0.8 30

LED pin current (Note 8) 10 120 mA Operating ambient temperature range -40 +125 °C

= +25°C, unless otherwise specified.)

IC = 1.0mA, IB = 0 IE = 10µA, IC = 0 VCE = 30V, V VCE = 30V, V

= 100µA, VCE = 1.0V

= 1.0mA, VCE = 1.0V

= 10mA, VCE = 1.0V

IC = 10mA, IB = 1.0mA IC = 10mA, IB = 1.0mA

IC = 50μA, IE = 0 IC = 1mA, IB = 0 IE = 50μA, IC = 0 VCB = 30V, IE = 0 V

= 4V, IC = 0

IC = 10mA, IB = 1mA VCE = 5V, IC = 150mA

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EB(OFF)

= 3.0V = 3.0V

= +25°C, unless otherwise specified.)

40 — — V

6.0 — — V — — 50 nA — — 50 nA

40 70

100

— — —

— —

300

— — 0.20 V

0.65 — 0.85 V

30 — — V 30 — — V

5.0 — — V

— — 0.5 µA — — 0.5 µA — — 0.3 V

100 — — —

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Thermal Characteristics

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ADVANCE INFORMATION

AMBIENT TEMPERAURE (°C)

Fig. 2 Derating Curve

L5802

Fig. 3 Max Power vs. Area

Fig. 4 Thermal Resistance vs. Area

AL5802

Document number: DS35516 Rev. 9 - 2

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