Diodes PAM2803AAF095 Schematic [ru]
PAM2803
Document number: DS36400 Rev. 2 - 2
1 of 9
www.diodes.com
December 2014
© Diodes Incorporated
PAM2803
A Product Line of
Diodes Incorporated
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, RS, 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 RS 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.
Features
LED Power Efficiency: up to 90%
Current Accuracy: 5%(VIN = 3.6V to 1.8V @VF = 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
Pin Assignments
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
I
LED
= 750mA, RS = 0.127Ω
3W HIGH POWER WHITE LED DRIVER
Typical Applications Circuit
PAM2803
Document number: DS36400 Rev. 2 - 2
2 of 9
www.diodes.com
December 2014
© Diodes Incorporated
PAM2803
A Product Line of
Diodes Incorporated
Pin
Number
Pin
Name
Function
1
SW
Switch 2 GND
Ground 3 FB
Feedback 4 SHDN
Shut Down
5
VOUT
Output 6 VIN
Input
Parameter
Rating
Unit
Input Pin Voltage
-0.3 to +6
V
SW Pin Voltage
-0.3 to +6
SHDN, FB Pin Voltage
-0.3 to +6
Operating Temperature Range
-40 to +85
°C
Storage Temperature Range
-65 to +125
Lead Temperature (Soldering, 5 sec)
300
Parameter
Rating
Unit
Junction Temperature
-40 to +125
°C
Ambient Temperature
-40 to +85
Pin Description
Block Diagram
Absolute Maximum Ratings (@T
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.
Recommended Operating Conditions (@T
= +25°C, unless otherwise specified.)
A
= +25°C, unless otherwise specified.)
A
PAM2803
Document number: DS36400 Rev. 2 - 2
3 of 9
www.diodes.com
December 2014
© Diodes Incorporated
PAM2803
A Product Line of
Diodes Incorporated
Parameter
Symbol
Package
Max
Unit
Thermal Resistance (Junction to Case)
θ
JC
SOT23-6
130
°C/W
Thermal Resistance (Junction to Ambient)
θ
JA
SOT23-6
250
Internal Power Dissipation
PD
SOT23-6
400
mW
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
Input Voltage Range
VIN
0.9
VF-0.2
(Note 1)
V
Feedback Voltage
VFB
90
95
100
mV
Start-Up Voltage
V
START
VIN: 0V – 3V, I
LED
= 370mA
0.9 V
Hold Voltage
V
HOLD
VIN: 3V – 0V, I
LED
: 750mA – 200mA
0.75 V
Oscillator Frequency
F
OSC
0.85
1.0
1.15
MHz
SHDN Input High
VSH
VIN = 1.8V
1.0
V
SHDN Input Low
VSL
VIN = 1.8V
0.4
V
Over Temperature Shutdown
OTS
150 °C
Over Temperature Hysteresis
OTH
15 °C
Maximum Output Current Range
I
O(MAX)
750
mA
Quiescent Current
IQ
I
LED
= 0mA, VO = 3.4V,
Device Switching @ 1MHz
1 3 mA
Shutdown Current
ISD
Shutdown Mode
1 µA
Switch On Resistance
R
DS(ON)
VO = 3.4V
0.1 Ω
Current Limit
I
LIM
VO = 3.4V
2
A
Efficiency
η
I
LED
= 750mA
90 %
Thermal Information
Electrical Characteristics
(@TA = +25°C, VIN = 2.4V, I
= 750mA, V
LED
= VIN, L = 2.2µH, CIN = 10µF, CO = 10µF, unless otherwise specified.)
SHDN
Note: 1. VF – LED forward voltage.
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