Diodes AL8806 User Manual

A

L8806

HIGH EFFICIENCY 36V 1.5A BUCK LED DRIVER

Description

The AL8806 is a step-down DC/DC converter designed to drive LEDs
with a constant current. The device can drive up to 8 LEDs,
depending on the forward voltage of the LEDs, in series from a
voltage source of 6V to 36V. The AL8806 switches at frequencies up
to 1MHz. This allows the use of small size external components,
hence minimizing the PCB area needed.

Maximum output current of AL8806 is set via an external resistor
connected between the V
by applying either a DC voltage or a PWM signal at the CTRL input
pin. An input voltage of 0.4V or lower at CTRL switches off the output
MOSFET simplifying PWM dimming.

and SET input pins. Dimming is achieved

IN

Features

 LED driving current up to 1.5A
 Better than 5% accuracy
 High efficiency up to 98%
 Operating input voltage from 6V to 36V
 High switching frequency up to 1MHz
 PWM/DC input for dimming control
 Built-in output open-circuit protection
 MSOP-8EP: Available in “Green” Molding Compound (No Br,

Sb) with lead Free Finish/ RoHS Compliant

 Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
 Halogen and Antimony Free. “Green” Device (Note 3)

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.

Pin Assignments

SET

SET

GND

GND
GND

GND

CTRL

CTRL

Applications

 High Power MR16 Lamps
 General Illumination Lamps
 Multi-Die LED Driver

1

1
2

2

AL8806

AL8806

3

3
4

4

MSOP-8EP

V

V

8

8

IN

IN

7

7

N/C

N/C

6

6

SW

SW

5

5

SW

SW

Typical Applications Circuit

D2 D3

DFLS230LH

12V

~

AC

x4

D4 D5

AL8806

Document number: DS35144 Rev. 5 - 2

C1

450µF

DFLS230LH

D1

R

SET

0R089

IN

V

AL8806

CTRL

GND

1 of 15

www.diodes.com

SET

SW

33µH L1

C2

1µF

Multi-

die

LED

July 2013

© Diodes Incorporated

A

Pin Descriptions

Pin Number

Pin

Name

GND 2, 3 GND Pin

CTRL 4

SET 1 Set Nominal Output Current Pin. Configure the output current of the device.

N/C 7 no connection

MSOP-8EP

SW 5, 6 Switch Pin. Connect inductor/freewheeling diode here, minimizing track length at this pin to reduce EMI.

Dimming and On/Off Control Input.
 Leave floating for normal operation.

(V

= V

= 2.5V giving nominal average output current I

REF

< 2.5V) to adjust output current from 20% to 100% of I

CTRL

 Drive to voltage below 0.4V to turn off output current
 Drive with DC voltage (0.5V < V
 A PWM signal (low level ≤ 0.4V and high level > 2.6; transition times less than 1us) allows the output current to be

VIN

EP EP

8

Input Supply Pin. Must be locally decoupled to GND with >
more information.

Exposed pad:
Connect to GND and thermal mass for enhanced thermal impedance. It should not be used as electrical ground

conduction path.

CTRL

adjusted below the level set by the resistor connected to SET input pin.

Function

= 0.1/RS)

OUTnom

OUTnom

2.2µF X7R ceramic capacitor – see applications section for

Functional Block Diagram

L8806

AL8806

Document number: DS35144 Rev. 5 - 2

2 of 15

www.diodes.com

July 2013

© Diodes Incorporated

A

L8806

Absolute Maximum Ratings (@T

Symbol Parameter Ratings Unit

ESD HBM Human Body Model ESD Protection 2.5 kV

ESD MM Machine Model ESD Protection 200 V

VIN Continuous VIN pin voltage relative to GND

VSW

V

CTRL

I

SW-RMS

I

SW-PK

TJ

T

LEAD

T

ST

Caution: Stresses greater than the 'Absolute Maximum Ratings' specified above, may cause permanent damage to the device. These are stress ratings only;

SW voltage relative to GND -0.3 to +40 V
CTRL pin input voltage -0.3 to +6 V
DC or RMS switch current 1.65 A
Peak switch current (<10%) 3 A
Junction Temperature 150 °C
Lead Temperature Soldering 300 °C
Storage Temperature Range -65 to +150 °C

functional operation of the device at these or any other conditions exceeding those indicated in this specification is not implied. Device reliability may be
affected by exposure to absolute maximum rating conditions for extended periods of time.
Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when handling
and transporting these devices.

Recommended Operating Conditions (@T

Symbol Parameter Min Max Unit

VIN

V

CTRLH

V

CTRLDC

V

CTRLL

ISW

f

OSC

TJ

Operating Input Voltage relative to GND 6.0 36 V
Voltage High for PWM dimming relative to GND 2.6 5.5 V
Voltage range for 20% to 100% DC dimming relative to GND 0.5 2.5 V
Voltage Low for PWM dimming relative to GND 0 0.4 V
DC or RMS switch current 1.5 A
Switching Frequency 1 MHz
Junction Temperature Range -40 +125 °C

Electrical Characteristics (@V

Symbol Parameter Conditions Min Typ Max Unit

V

INSU

V

INSH

IQ

IS

VTH

V

TH-H

I

SET

R

CTRL

V

REF

R

DS(on)

I

SW_Leakage



JA



JC

Notes: 4. AL8806 does not have a low power standby mode but current consumption is reduced when output switch is inhibited: V
tested with V

5. Dominant conduction path via exposed pad. Refer to figure 5 for the device derating curve.

6. Measured on an FR4 51x51mm PCB with 2oz copper standing in still air with minimum recommended pad layout on top layer and thermal vias to
bottom layer maximum area ground plane. For better thermal performance, larger copper pad for heat-sink is needed.

Internal regulator start up threshold
Internal regulator hysteresis threshold
Quiescent current Output not switching
Input supply Current CTRL pin floating f = 250kHz 1.8 5 mA
Set current Threshold Voltage
Set threshold hysteresis ±20 mV
SET pin input current
CTRL pin input resistance Referred to internal reference 50 kΩ
Internal Reference Voltage 2.5 V
On Resistance of SW MOSFET
Switch leakage current
Thermal Resistance Junction-to-Ambient (Note 5) MSOP-8EP (Note 6) 69
Thermal Resistance Junction-to-Case (Note 5) MSOP-8EP (Note 6) 4.3

≤ 2.5V

CTRL

= +25°C, unless otherwise specified.)

A

-0.3 to +40 V

= +25°C, unless otherwise specified.)

A

= 12V, TA = +25°C, unless otherwise specified.)

IN

VIN rising
VIN falling

(Note 4) 350 µA

V

≥ 2.6V or floating.

CTRL

V

= VIN-0.1

SET

ISW = 1A
VIN =36V

5.9 V

100 300 mV

95 100 105 mV

16 22 µA

0.18 0.35 Ω

0.5 μA

C/W

= 0V. Parameter is

SENSE

AL8806

Document number: DS35144 Rev. 5 - 2

3 of 15

www.diodes.com

July 2013

© Diodes Incorporated

A

0

CUR

RENT

Typical Performance Characteristics

40

V = 0V

CTRL

V = V

350

SET IN

°

T = 25C

A

300

250

200



IN

I (µA)

150

100

50

0

0 5 10 15 20 25 30

V (V)

IN

Supply Current (not switching) vs. Input Current

1.6

1.4

T = 25°C

A

L =68µH

R = 68m

SET



L8806

900

L = 33µ H

800
700

600

L = 68µ H

500
400

Frequency (kHz)

300

200

L = 100 µ H

100

0

012345

80

60

Switching Frequency vs. V

V = V = 12V

SET IN



T = 25C

A

V(V)

CTR L

V = 12V

IN

1 LED
R = 150m

SET

T = 25°C

A

CTRL



1.2

R = 100m

(A)

1

0.8

SET

R = 150m

SET

0.6

LED

0.4

0.2

0

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5

CTRL VOLTAGE (V)

2.5

1.5

CTRL

V (V)

0.5

LED Current vs. V

3

2

1

CTRL

V= Open

CTRL

V = V

SET IN

T = 25C

A



40

20



CTRL

I (µA)

0

-20

-40

-60

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
V (V)

CTRL

I vs V

CTRL CTRL

2.52

V = Open

CTRL

V = V = 12V

SET IN

2.51

2.50

CTRL

V (V)



2.49

0

0 5 10 15 20 25 30

V (V)
V vs. Input Voltage
(CTRL pin open circuit)

IN

CTRL

2.48

-40 -15 10 35 60 85 110
Ambient Temperature (°C)

V vs. Temperature

CTRL

AL8806

Document number: DS35144 Rev. 5 - 2

4 of 15

www.diodes.com

July 2013

© Diodes Incorporated

A

R (m

%

Typical Performance Characteristics (cont.)

5.0

V = 12V

4.5

4.0

IN

1 LE D
R = 150m

SET

L = 68µ H

3.5

3.0

2.5

LED Current E rror

2.0

I

1.5

LED Current Error (%)

LED

1.0

0.5

0.0
0% 20% 40% 60% 80% 100%

PWM Duty Cycle

I vs. PWM Duty Cycle

LED

260
240

220

)

200



180

DS(ON)

160
140
120
100

-40 -15 10 35 60 85 110

V = Open

CTRL

V = V 12V

SET IN

AMBIENT TEMPERATURE (°C)

SW R vs. Temperature

DS(ON)

100

90%
80%

L = 33µ H
R = 150m

SET

T = 25C

A

2 LE D

70%

1

0.9



0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1
0





L8806

200
180
160
140



120
100

DS(ON)

80

LED Current (A)

R (m)

60
40
20

0

051015

R vs. Input Voltage

DS(ON)

V (V)

IN

V = Open

CTRL

V = V 12V

SET IN



T = 25C

A

20 25 30

130
125
120

V

SEN SE

115

V

110

SW

105

SENSE

100

V (mV)

95
90

85
80

02468

R = 150m

SET

L = 68µ H
V = 12V

IN

1 LED Load

Time (µs)



SW Output Switching Characteristics

18
16

14
12

10

8
6
4

2
0

-2

SW

V

60%
50%

Duty Cycle

40%
30%
20%
10%

0%

6 9 12 15 18 21 24 27 30

Input Voltage (V)

Duty Cycle vs. Input Voltage

AL8806

Document number: DS35144 Rev. 5 - 2

5 of 15

www.diodes.com

July 2013

© Diodes Incorporated

A

%

%

%

Typical Operating Performance Characteristics (cont.)

10

8%
6%
4%
2%
0%

-2%

% ERROR

-4%

-6%

-8%

-10%

700

600

1.5A Nominal LED Current 1.0A Nominal LED Current

5 LEDs

6 LEDs

7 LEDs

8 LEDs

2 LEDs

3 LEDs

1 LED

T = 25°C

A

L = 33µH
R = 66.67m

S

4 LEDs



6 9 12 15 18 21 24 27 30

T = 25°C

A

L = 33µH
R = 66.67m

S

INPUT VOLTAGE (V)



10

8%
6%
4%

2 LEDs

3 LEDs

4 LEDs

5 LEDs

6 LEDs

7 LEDs

2%

1 LED

0%

-2%

DEVIATION

-4%

-6%

T = 25°C

A

L = 33µH

-8%

R = 100m

-10%
6 9 12 15 18 21 24 27 30



S

INPUT VOLTAGE (V)

700

T = 25°C

A

L = 33µH

600

R = 100m



S

L8806

8 LEDs

500

400

300

200

1 LED

100

SWITCHING FREQUENCY (kHZ)

0

2 LEDs

3 LEDs

4 LEDs 5 LEDs

6 LEDs 7 LEDs

6 9 12 15 18 21 24 27 30

INPUT VOLTAGE (V)

100%

7 LEDs

6 LEDs

5 LEDs

4 LEDs

95%

3 LEDs

2 LEDs

90%

85%

1 LED

80%

T = 25°C

A

L = 33µH
R = 66.67m

75%

S

6 9 12 15 18 21 24 27 30



INPUT VOLTAGE (V)

8 LEDs

8 LEDs

500

400

300

200

1 LED

SWITCHING FREQUENCY (kHz)

100

2 LEDs

3 LEDs

4 LEDs

5 LEDs

6 LEDs

0

7 LEDs

6 9 12 15 18 21 24 27 30

INPUT VOLTAGE (V)

100

95%

2 LEDs

3 LEDs

4 LEDs

5 LEDs

6 LEDs

7 LEDs

90%

1 LED

85%

EFFICIENCY

80%

T = 25°C

A

L = 33µH
R = 100m

75%

6 9 12 15 18 21 24 27 30



S

INPUT VOLTAGE (V)

8 LEDs

8 LEDs

AL8806

Document number: DS35144 Rev. 5 - 2

6 of 15

www.diodes.com

July 2013

© Diodes Incorporated

A

L8806

Application Information

AL8806 Operation

In normal operation, when voltage is applied at VIN, the AL8806 internal switch is turned on. Current starts to flow through sense resistor R
inductor L1, and the LEDs. The current ramps up linearly, and the ramp rate is determined by the input voltage V

DFLS230LH

DFLS230LH

D1

12V

12V

GND

GND

C1

C1

4.7µF

4.7µF

C2

C2

100nF

100nF

D1

R

R

SET

SET

0R082

0R082

IN

IN

V

V

AL8806

AL8806

CTRL

CTRL

GND

GND

SET

SET

SW

SW

33µH

C3

C3

1µF

1µF

L1

Figure 1 Typical Application Circuit

This rising current produces a voltage ramp across R
proportional voltage to the input of the internal comparator.

When this voltage reaches an internally set upper threshold, the internal switch is turned off. The inductor current continues to flow through R
L1, the LEDs and the schottky diode D1, and back to the supply rail, but it decays, with the rate of decay determined by the forward voltage drop of
the LEDs and the schottky diode.

This decaying current produces a falling voltage at R
applied at the input of the internal comparator. When this voltage falls to the internally set lower threshold, the internal switch is turned on again.

This switch-on-and-off cycle continues to provide the average LED current set by the sense resistor R

. The internal circuit of the AL8806 senses the voltage across R

SET

, which is sensed by the AL8806. A voltage proportional to the sense voltage across R

1

.

SET

and the inductor L1.

IN

Multi-

Multi-

die

die

LED

LED

and applies a

SET

LED Current Control

The LED current is controlled by the resistor R
Connected between V

If the CTRL pin is driven by an external voltage (higher than 0.4V and lower than 2.5V), the average LED current is:

For example for a desired LED current of 1.33A and a default voltage V

and SET the nominal average output current in the LED(s) is defined as:

IN

in Figure 1.

SET

R

SET

V

I

LED

THD

I 

LED

V

V

THD

I 

LED

V

CTRL

CTRL

V

REF

V

R

SET

V

CTRL

THD

R

SET

REF

=2.5V the resulting resistor is:

5.2

1.0

5.2

33.1

 m75

DC Dimming

The CTRL pin can be driven by an external DC voltage (V

. The LED current decreases linearly with the CTRL voltage when 0.5V ≤ V

R

SET

Note that 100% brightness setting corresponds to V
the device will not overdrive the LED current and will still set the current according to the equation V

When the CTRL voltage falls below the threshold, 0.4V, the output switch is turned off which allows PWM dimming.

CTRL

), to adjust the output current to a value below the nominal average value defined by

CTRL

≤ 2.5V, as shown on page 4 for 4 different current levels.

CTRL

= V

, nominally 2.5V. For any voltage applied on the CTRL pin that is higher than V

REF

= V

REF

.

CTRL

SET

SET

SET

is

REF

,

,

,

AL8806

Document number: DS35144 Rev. 5 - 2

7 of 15

www.diodes.com

July 2013

© Diodes Incorporated

A

]

]

L8806

Application Information (cont.)

PWM Dimming

LED current can be adjusted digitally, by applying a low frequency Pulse Width Modulated (PWM) logic signal to the CTRL pin to turn the device on
and off. This will produce an average output current proportional to the duty cycle of the control signal. In particular, a PWM signal with a max
resolution of 10bit can be applied to the CTRL pin to change the output current to a value below the nominal average value set by resistor R
achieve this resolution the PWM frequency has to be lower than 500Hz, however higher dimming frequencies can be used - at the expense of
dimming dynamic range and accuracy.

Typically, for a PWM frequency of 500Hz the accuracy is better than 1% for PWM ranging from 1% to 100%.

700

600

500

400

SET

. To

300

200

LED curre nt [m A

100

0

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

PWM dim m ing [%]

Figure 2 PWM Dimming at 500Hz

70

60

50

40

30

20

LED current [mA

10

0

0% 1% 2% 3% 4% 5% 6% 7% 8% 9% 10%

PW M dim m ing [%]

Figure 3 Low Duty Cycle PWM Dimming at 500Hz

The PWM pin is designed to be driven by both 3.3V and 5V logic levels directly from a logic output with either an open drain output or push-pull
output stage.

AL8806

Document number: DS35144 Rev. 5 - 2

8 of 15

www.diodes.com

© Diodes Incorporated

July 2013

A

L8806

Application Information (cont.)

Soft Start

The AL8806 does not have in-built soft-start action – this provides very fast turn off of the output the stage improving PWM dimming accuracy;
nonetheless, adding an external capacitor from the CTRL pin to ground will provide a soft-start delay. This is achieved by increasing the time taken
for the CTRL voltage to rise to the turn-on threshold and by slowing down the rate of rise of the control voltage at the input of the comparator.
Adding a capacitor increases the time taken for the output to reach 90% of its final value, this delay is 0.1ms/nF, but will impact on the PWM
dimming accuracy depending on the delay introduced.

Figure 4 Soft Start with 22nF Capacitor on CTRL Pin (V

= 36V, I

IN

= 667mA, 1 LED)

LED

Reducing Output Ripple

Peak to peak ripple current in the LED(s) can be reduced, if required, by shunting a capacitor C2 a cross the LED(s) as shown al ready in the circuit
schematic.

A value of 1μF will reduce the supply ripple current by a factor three (approx.). Proportionally lo wer ripple can be achieved with higher capacitor
values. Note that the capacitor will not affect operating frequency or efficiency, but it will increase start-up delay, by reducing the rate of rise of
LED voltage. By adding this capacitor the current waveform through the LED(s) changes from a triangular ramp to a more sinusoidal version
without altering the mean current value.

AL8806

Document number: DS35144 Rev. 5 - 2

9 of 15

www.diodes.com

July 2013

© Diodes Incorporated

A

L8806

Application Information (cont.)

Capacitor Selection

The small size of ceramic capacitors makes them ideal for AL8806 applications. X5R and X7R types are recommended because they retain their
capacitance over wider voltage and temperature ranges than other types such as Z5U.

A 2.2μF input capacitor is sufficient for most intended applications of AL8806; however a 4.7μF input capacitor is suggested for input voltages
approaching 30V.

Diode Selection

For maximum efficiency and performance, the rectifier (D1) should be a fast low capacitance Schottky diode with low reverse leakage at the
maximum operating voltage and temperature. The Schottky diode also provides better efficiency than silicon PN diodes, due to a combination of
lower forward voltage and reduced recovery time.

It is important to select parts with a peak current rating above the peak coil current and a continuous current rating higher t h an th e maximum outpu t
load current. In particular, it is recommended to have a diode voltage rating at least 15% higher than the operating voltage to ensure safe operation
during the switching and a current rating at least 10% higher than the average diode current. The power rating is verified by calculating the power
loss through the diode.

Schottky diodes, e.g. B240 or B140, with their low forward voltage drop and fast reverse recovery, are the ideal choice for AL8806 applications.

Thermal and Layout Considerations

For continuous conduction mode of operation, the absolute maximum junction temperature must not be exceeded. The maximum p o wer dissipation
depends on several factors: the thermal resistance of the IC package 
and ambient temperature.

The maximum power dissipation can be calculated using the following formula:

where T

is the maximum operating junction temperature,

J(MAX)

, PCB layout, airflow surrounding the IC, and difference between junction

JA

T


The recommended maximum operating junction temperature, T
junction to ambient thermal resistance, 
enhanced MSOP-8EP package.



, is layout dependent and the AL8806’s JA in MSOP-8EP on a

JA

51 x 51mm double layer PCB with 2oz copper standing in still air is
approximately 69°C/W.

Therefore the maximum power dissipation at T

Figure 5, shows the power derating of the AL8806 on an FR4
51x51mm PCB with 2oz copper standing in still air.

As the ambient temperature increases and/or the PCB area reduces
the maximum allowable power dissipated by the AL8806 will
decrease.

AL8806

Document number: DS35144 Rev. 5 - 2

is the ambient temperature, and

A

is the junction to ambient thermal resistance.

JA

. To support high LED drive at higher ambient temperatures the AL8806 has been packaged in thermally

JA

= +25°C is:

A

P





)MAX(D

C25C125





W/C69



, is 125°C and so maximum ambient temperature is determined by the AL8806’s

J

W45.1

www.diodes.com

10 of 15

1600
1400
1200
1000

800
600
400

Power di s si pa t i on ( m W )

200

0

-40 -25 -10 5 20 35 50 65 80 95 110 125

MSOP-8EP

Ambient tem per at ure ( ° C)

Figure 5 Derating Curve

July 2013

© Diodes Incorporated

A

L8806

Application Information (cont.)

PCB Layout

When laying out the PCB for the AL8806 the following should be observed:

1. The decoupling capacitor C1 has to be placed as close as possible to V

2. The sense resistor, R

3. The anode of the freewheel diode (D1), the SW pin and the inductor have to be placed as close as possible to each other to avoid ringing.

, has to be placed as close as possible to VIN and SET

SET

R

SET

IN

To avoid
radiated EMI
keep dashed
tracks as
short as
possible

IN

V

AL8806

SET

D1

C2

C1

CTRL

GND

SW

L1

Figure 6 PCB Layout

The AL8806 has two evaluation boards available on request (AL8806EV4 and AL8806EV6). Information can be found on the Diodes website and
from a Diodes’ sales representative.

Application Example

A typical application example for the AL8806 is the MR16 lamp; which normally operate from 12VDC or 12VAC supplies, using conventional
electromagnetic transformers or electronic transformers.

As a replacement for MR16 halogen lamps, LED lamps offer a more energy efficient solution - radiating no h eat and no Ultra Violet light. The l ow
thermal impedance of the AL8806 and its 1.5A switch capability allows it drive some of the latest multi-die LEDs; which increases the lamp’s
luminance.

This application example is intended to fit into the base connector space of an MR16 style LED lamp . The design has been optimized f or pa rt coun t
and thermal performance for a multi-die LED in the Lens section as well as EMI conformance.

AL8806

Document number: DS35144 Rev. 5 - 2

Figure 7 MR16 Schematic

11 of 15

www.diodes.com

July 2013

© Diodes Incorporated

A

L8806

Application Information (cont.)

Application Example

The output of the 12V transformer is fed into the bridge rectifier, comprising of D2, D3, D4 and D5. C10 offers an optional EMI filtering at the input.
(see figure 9)

Capacitor, C
used to sustain operation of the device during the low part of the rectified AC wave. In the case of a system driving two LEDs at 1.1A, one 470µF
plus 47µF capacitors are required.

Capacitors C3 and C9 provide local decoupling for the AL8806 and for the schottky freewheeling diode, D1. It is important that C3 i s as close as
possible to the AL8806’s V

The LED current is determined by the total resistance between the V
BOM).

C4 decouples the LED connections, again to minimize EMI, as well as smoothing the current.
D1 operates as the freewheeling diode, providing a current path for the LED current when the power switch at SW pin is off.

Capacitors C5 to C9, 1.5nF have been added to improve the overall EMI performa nce. C5 is connected across the Suppl y pins to reduce radiation
via the wiring. C6 and C7 also assist the reduction of EMI via the wiring. C8 snubs high frequency radiation f rom the harmonics in the switching
regulator.

A large number of vias have been used to improve the grounding effect throughout the PCB to improve the evaluation board’s EMI performance.

BULK

(cont.)

, (capacitors C1 and C2 on the PCB and BOM are multiple components to reduce size) forms the bulk reservoir capacitance -

pin and that C9 is as close to the VIN and shottky diode as possible, as reflected in the layout shown below in figure 8.

IN

and SET pins (R1 and R2 in figures 7 (schematic) and 8 (top PCB) and

IN

Figure 8 AL8806EV6 evaluation board (Top)

AL8806

Document number: DS35144 Rev. 5 - 2

12 of 15

www.diodes.com

Figure 9 AL8806EV6 evaluation board (Bottom)

© Diodes Incorporated

July 2013

A

L8806

Application Information (cont.)

AL8806EV6 BOM

Count Designator Description Package Manufacturer Part Number

1 C1 Capacitor, 470uF, 25V Aluminium Electrolytic
1 C2 Capacitor, 4.7µF 10% 50V X7R 1210 Kemet C1210X475K5RAC

3 C3, C9, C10 Capacitor, 100nF 10% 50V X7R 0805

1 C4 Capacitor, 100nF 10% 50V X7R 1206

4 C5 to C8 Capacitor, 1.5nF 10% 50V or 100V, COG 0805 generic

1 L1 Inductor, shielded, 15µH 20% 6.6 x 6.6mm

1 L2 Inductor, ferrite bead, 6A, 30ohms @100MHz 0805 TDK MPZ2012S300A
1 R1 Resistor, 0.15ohms 1% 250ppm 125mW 0805 generic
1 R2 Resistor, 0.2ohms 1% 250ppm 125mW 0805 generic

1 D1
4 D2 to D5 Diode, Super Barrier Rectifier, 36V 2A SBR2U30 PowerDi123 Diodes Inc SBR2U30P1-7

1 U1 IC, LED Driver, AL8806 MSOP-8EP Diodes Inc AL8806MP8-13

Diode, schottky, 36V 2A DFLS230 (alternatives:
DFLS230L or LH)

Radial,

10 x 12.5mm

PowerDi123 Diodes Inc DFLS230-7

Rubycon 25ZLH470M

Kemet

NIC

Kemet

NIC

Coilcraft

NIC

Würth

C1210X475K5RAC

NMC0805X7R104K50TRPF

C1206104K5RAC7800

NMC1206X7R104K50TRPF

MSS7341-153ML

NPIS64D150MTRF

744777115

The AL8806 guarantees high level of performance both with 12VAC and 12VDC power supply.

Ordering Information

AL8806 XXX - XX

AL8806 XXX - XX

Package

Package

MP8 : MSOP-8EP

MP8 : MSOP-8EP

Packing

Packing

13 : 13” Tape & Reel

13 : 13” Tape & Reel

Part Number Package Code Packaging

AL8806MP8-13 MP8 MSOP-8EP 2500/Tape & Reel -13

AL8806

Document number: DS35144 Rev. 5 - 2

13 of 15

www.diodes.com

Quantity Part Number Suffix

Tape and Reel

July 2013

© Diodes Incorporated

A

Marking Information

MSOP-8EP

L8806

Part Number Package

AL8806MP8-13 MSOP-8EP

Package Outline Dimensions (All dimensions in mm.)

Please see AP02002 at http://www.diodes.com/datasheets/ap02002.pdf for latest version.

D

x

y

1

A

e

A1

D

E

8Xb

A2

E2

A3

D1

E3

E1

Gauge Plane
Seating Plane

See Detail C

0.25

4

X

1

c

0

°

4

X

Detail C

1

0

°

a

L

Suggested Pad Layout

Please see AP02001 at http://www.diodes.com/datasheets/ap02001.pdf for the latest version.

X C

G

Y2

AL8806

Document number: DS35144 Rev. 5 - 2

X1

Y

Y1

Dimensions

14 of 15

www.diodes.com

MSOP-8EP

Dim Min Max Typ

A - 1.10 ­A1 0.05 0.15 0.10
A2 0.75 0.95 0.86
A3 0.29 0.49 0.39

b 0.22 0.38 0.30
c 0.08 0.23 0.15

D 2.90 3.10 3.00
D1 1.60 2.00 1.80

E 4.70 5.10 4.90
E1 2.90 3.10 3.00
E2 1.30 1.70 1.50
E3 2.85 3.05 2.95

e - - 0.65
L 0.40 0.80 0.60
a 0° 8° 4°
x - - 0.750
y - - 0.750

All Dimensions in mm

Value

(in mm)

C 0.650

G 0.450

X 0.450

X1 2.000

Y 1.350
Y1 1.700
Y2 5.300

July 2013

© Diodes Incorporated

A

L8806

DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
(AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).

Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes
without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the
application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or
trademark rights, nor the rights of others. Any Customer or user of this document or products described herein in such applications shall assume
all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated
website, harmless against all damages.

Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthorized sales channel.
Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorize d application, Customers shall indemnify and
hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or
indirectly, any claim of personal injury or death associated with such unintended or unauthorized application.

Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings
noted herein may also be covered by one or more United States, international or foreign trademarks.

This document is written in English but may be translated into multiple languages for reference. Onl y the English version of this document is the
final and determinative format released by Diodes Incorporated.

Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express
written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:

A. Life support devices or systems are devices or systems which:

1. are intended to implant into the body, or

2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the

labeling can be reasonably expected to result in significant injury to the user.
B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the

failure of the life support device or to affect its safety or effectiveness.
Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and

acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any
use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related
information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its
representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems.

Copyright © 2013, Diodes Incorporated

www.diodes.com

IMPORTANT NOTICE

LIFE SUPPORT

AL8806

Document number: DS35144 Rev. 5 - 2

15 of 15

www.diodes.com

July 2013

© Diodes Incorporated