A Product Line of
Diodes Incorporated
PAM2803
3W HIGH POWER WHITE LED DRIVER
Description
The PAM2803 is a step-up DC-DC converter that delivers a regulated
output current. The device switches at a 1.0MHz constant frequency,
allowing for the use of small value external inductor and ceramic
capacitors.
The PAM2803 is targeted to be used for driving loads up to 1A from a
two-cell alkaline battery. The LED current can be programmed by the
external current sense resistor, R
S
, connected between the feedback
pin (FB) and ground. A low 95mV feedback voltage reduces the
power loss in the Rs for better efficiency. With its internal 2A, 100mΩ
NMOS switch, the device can provide high efficiency even at heavy
load. During the shutdown mode, the feedback resistor R
S
and the
load are completely disconnected and the current consumption is
reduced to less than 1µA.
The PAM2803 is available in the 6-lead SOT23-6 package.
Pin Assignments
Features
LED Power Efficiency: up to 90%
Current Accuracy: 5%(V
IN
= 3.6V to 1.8V @V
F
= 3.7V)
Low Start-Up Voltage: 0.9V (I
LED
= 270mA)
Low Hold Voltage: 0.75 (I
LED
= 200mA)
1MHz Switching Frequency
Uses Small, Low Profile External Components
Low R
DS(ON)
: 100mΩ (typ)
Over Temperature Protection
Low Profile SOT23-6 Package
Pb-Free Package
Applications
White LED Torch (Flashlight)
White LED Camera Flash
DSC (Digital Still Camera) Flash
Cellular Camera Phone Flash
PDA Camera Flash
Camcorder Torch (Flashlight) Lamp
Typical Applications Circuit
I
LED
= 750mA, R
S
= 0.127Ω
PAM2803
Document number: DS36400 Rev. 2 - 2
1 of 9
www.diodes.com
December 2014
© Diodes Incorporated
A Product Line of
Diodes Incorporated
PAM2803
Pin Description
Pin
Number
1
2
3
4
5
6
Pin
Name
SW
GND
FB
SHDN
VOUT
VIN
Switch
Ground
Feedback
Shut Down
Output
Input
Function
Block Diagram
Absolute Maximum Ratings
(@T
A
= +25°C, unless otherwise specified.)
These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may
affect device reliability. All voltages are with respect to ground.
Parameter
Input Pin Voltage
SW Pin Voltage
SHDN, FB Pin Voltage
Operating Temperature Range
Storage Temperature Range
Lead Temperature (Soldering, 5 sec)
Rating
-0.3 to +6
-0.3 to +6
-0.3 to +6
-40 to +85
-65 to +125
300
Unit
V
°C
Recommended Operating Conditions
(@T
A
= +25°C, unless otherwise specified.)
Parameter
Junction Temperature
Ambient Temperature
Rating
-40 to +125
-40 to +85
Unit
°C
PAM2803
Document number: DS36400 Rev. 2 - 2
2 of 9
www.diodes.com
December 2014
© Diodes Incorporated
A Product Line of
Diodes Incorporated
PAM2803
Thermal Information
Parameter
Thermal Resistance (Junction to Case)
Thermal Resistance (Junction to Ambient)
Internal Power Dissipation
Symbol
θ
JC
θ
JA
P
D
Package
SOT23-6
SOT23-6
SOT23-6
Max
130
250
400
Unit
°C/W
mW
Electrical Characteristics
(@T
A
= +25°C, V
IN
= 2.4V, I
LED
= 750mA, V
SHDN
= V
IN
, L = 2.2µH, C
IN
= 10µF, C
O
= 10µF, unless otherwise specified.)
Parameter
Input Voltage Range
Feedback Voltage
Start-Up Voltage
Hold Voltage
Oscillator Frequency
SHDN Input High
SHDN Input Low
Over Temperature Shutdown
Over Temperature Hysteresis
Maximum Output Current Range
Quiescent Current
Shutdown Current
Switch On Resistance
Current Limit
Efficiency
Note:
1. VF – LED forward voltage.
Symbol
V
IN
V
FB
V
START
V
HOLD
F
OSC
V
SH
V
SL
OTS
OTH
I
O(MAX)
I
Q
I
SD
R
DS(ON)
I
LIM
η
V
IN
= 1.8V
V
IN
= 1.8V
Test Conditions
V
IN
: 0V – 3V, I
LED
= 370mA
V
IN
: 3V – 0V, I
LED
: 750mA – 200mA
Min
0.9
90
0.85
1.0
Typ
95
0.9
0.75
1.0
150
15
1
Max
V
F
-0.2
(Note 1)
100
1.15
0.4
3
1
Units
V
mV
V
V
MHz
V
V
°C
°C
mA
mA
µA
Ω
A
%
I
LED
= 0mA, V
O
= 3.4V,
Device Switching @ 1MHz
Shutdown Mode
V
O
= 3.4V
V
O
= 3.4V
I
LED
= 750mA
750
2
0.1
90
PAM2803
Document number: DS36400 Rev. 2 - 2
3 of 9
www.diodes.com
December 2014
© Diodes Incorporated
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