AL8811
Document number: DS36090 Rev. 2 - 2
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© Diodes Incorporated
A
L8811
Boost/Buck/Inverting DC-DC CONVERTER
Description
The AL8811 is a monolithic control circuit containing the primary
functions required for DC-to-DC converters. These devices consist of
an internal temperature compensated reference, comparator,
controlled duty cycle oscillator with an active current limit circuit, driver
and high current output switch. This series is specifically designed for
incorporating in Boost, Buck and voltage-inverting applications with a
minimum number of external components.
Features
Operation from 3.0V to 20V Input
Low Standby Current
Current Limiting
Output Switch Current to 1.6A
Output Voltage Adjustable
Frequency Operation to 100 kHz
Precision 2% Reference
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
Pin Assignments
MSOP-8
Applications
Low Voltage LED Lighting such as MR-16
General Purpose DC-DC Converter
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.
Typical Application Diagram
Electronic Transformer compatible MR16 lamp Simplified Schematic
AL8811
Document number: DS36090 Rev. 2 - 2
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June 2013
© Diodes Incorporated
A
L8811
Pin Descriptions
Pin Name Pin Number Descriptions
Current
Switch+
1
Internal switch transistor collector:
Connect to Inductor for boost converter.
Connect to V
CC
for Buck or Inverting converter
Current
Switch-
2
Internal switch transistor emitter:
Connect to GND for boost converter
Connect to Inductor for buck or inverting converter
CT 3 Timing Capacitor to control the switching frequency
GND 4
Feedback 5 Feedback pin for inverting input of internal comparator
VCC 6 Supply voltage pin
Current
Sense
7
Peak Current Sense Input by monitoring the voltage drop across an external current sense
resistor to limit the peak current through the switch
Current
Drive
8
Current drive collector:
Normally connected to V
CC
directly or via a resistor.
Functional Diagram
AL8811
Document number: DS36090 Rev. 2 - 2
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© Diodes Incorporated
A
L8811
Absolute Maximum Ratings (@T
A
= +25°C, unless otherwise specified.)
Symbol Parameter Rating Unit
V
CC
Power Supply Voltage 20 V
V
IR
Comparator Input Voltage Range -0.3 to +36 V
V
C (SWITCH)
“Current Switch +” Collector Voltage 36 V
V
E (SWITCH)
„Current Switch –„ Emitter Voltage (V
PIN
1 = 36V)
36 V
V
CE (SWITCH)
“Current Switch” Collector to Emitter Voltage 36 V
V
C (DRIVER)
“Current Drive” Collector Voltage 36 V
I
C (DRIVER)
“Current Drive” Collector Current 100 mA
I
SW
“Current Switch” Current 1.6 A
P
D
Power Dissipation (Note 4) 600 mW
JA
Thermal Resistance 130
C/W
T
MJ
Maximum Junction Temperature +150
C
T
STG
Storage Temperature Range -65 to +150
C
ESD HBM Human Body Model ESD Protection 1 kV
ESD MM Machine Model ESD Protection 150 V
Caution: Stresses greater than the 'Absolute Maximum Ratings' specified above, may cause permanent damage to the device. These are stress ratings only;
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
Symbol Parameter Min
Max
Unit
V
CC
Supply Voltage 3 20 V
T
OP
Operating Junction Temperature Range
-40
+105
C
Electrical Characteristics (@ V
CC
= 5V, T
A
= +25°C, unless otherwise specified.)
Symbol Parameter Min Typ Max Unit
OSCILLATOR
f
OSC
Frequency (V
PIN
5 = 0V, C
T
= 1.0nF, T
A
= +25°C)
24 33 42 kHz
I
CHG
Charge Current (V
CC
= 5.0V to 20V, T
A
= +25°C)
24 30 42 µA
I
DISCHG
Discharge Current (V
CC
= 5.0V to 20V, T
A
= +25°C)
140 200 260 µA
I
DISCHG
/ I
CHG
Discharge to Charge Current Ratio (Pin 7 to V
CC
, T
A
= +25°C)
5.2 6.5 7.5
V
IPK (SENSE)
Current Limit Sense Voltage (I
CHG
= I
DISCHG
, T
A
= +25°C)
300 400 450 mV
OUTPUT SWITCH (Note 4)
V
CE(sat)
Saturation Voltage, Darlington Connection
(I
SW
= 1.0A, Pins 1, 8 connected)
— 1.0 1.3 V
V
CE(sat)
Saturation Voltage, Darlington Connection
(I
SW
= 1.0A, ID = 50mA, Forced ß 20)
— 0.45 0.7 V
h
FE
DC Current Gain (I
SW
= 1.0A, V
CE
= 5.0V, T
A
= +25°C)
50 75
I
C(off)
Collector Off-State Current (V
CE
= 20V)
— 0.01 100 µA
COMPARATOR
V
th
Threshold Voltage T
A
= +25°C
1.225 1.25 1.275 V
Reg
(LINE)
Threshold Voltage Line Regulation (V
CC
= 3.0V to 20V)
— 1.4 6.0 mV
TOTAL DEVICE
I
CC
Supply Current (V
CC
= 5.0V to 20V, C
T
=1.0nF, Pin 7 = V
CC
,
V
PIN 5
> V
th
Pin 2 = Gnd, remaining pins open)
3.5 mA

AL8811M8-13

Mfr. #:
Manufacturer:
Diodes Incorporated
Description:
Switching Voltage Regulators Boost/Buck/Inv DC-DC 3 - 20V 1.6A 100kHz
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
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