A Product Line of
Diodes Incorporated
PAM2863
2A LED DRIVER with INTERNAL SWITCH
Description
The PAM2863 is a continuous mode inductive step-down converter,
designed for driving single or multiple series connected LEDs
efficiently from a voltage source higher than the LED voltage. The
device operates from an input supply between 4.5V and 40V and
provides an externally adjustable output current of up to 2A.
Depending upon supply voltage and external components, this can
provide up to 30 watts of output power.
The PAM2863 includes the output switch and a high-side output
current sensing circuit, which uses an external resistor to set the
nominal average output current.
Output current can be adjusted below the set value, by applying an
external control signal to the VSET pin.
The VSET pin will accept either a DC voltage or a PWM waveform.
The soft-start time can be increased using an external capacitor from
the VSET pin to ground. Applying a voltage of 0.2V or lower to the
VSET pin turns the output off and switches the device into a low
current standby state.
Pin Assignments
Applications
•
•
High End LED Flashlight
LED Light Bar
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
Simple Low Parts Count
Internal 40V NDMOS Switch
2A Output Current
Single Pin On/Off and Brightness Control Using DC Voltage or
PWM
Soft-Start
High Efficiency (up to 97%)
Wide Input Voltage Range: 4.5V to 40V
Output Shutdown
Open LED Protection
Short LED Protection
Up to 1MHz Switching Frequency
Typical 5% Output Current Accuracy
Pb-Free SOP-8(EP) Packages
PAM2863
Document number: DSxxxxx Rev. 1 - 0
1 of 11
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October 2012
© Diodes Incorporated
A Product Line of
Diodes Incorporated
PAM2863
Typical Applications Circuit
Pin Descriptions
Pin
Number
5, 6
3, 7, 8
Pin
Name
LX
GND
Function
Drain of NDMOS switch.
Ground (0V)
• Multi-function On/Off and brightness control pin:
• Leave floating for normal operation.
• Drive to voltage below 0.2V to turn off output current
• Drive with DC voltage (0.3V < VSET< 2.5V) to adjust output current from 12% to 100% of I
OUTnom
• Drive with PWM signal from open-collector or open-drain transistor, to adjust output
current. Adjustment range 1% to 100% of I
OUTnom
for f < 500Hz
• Connect a capacitor from this pin to ground to increase soft-start time. (Default soft-start time = 0.1ms.
Additional soft-start time is approx.1.5ms/1nF)
Connect resistor RS from this pin to VIN to define nominal average output current IOUTnom = 0.1/Rs
Input voltage (6V to 40V). Decouple to ground with 10μF or higher X7R ceramic capacitor close to device.
4
VSET
2
1
ISENSE
VIN
PAM2863
Document number: DSxxxxx Rev. 1 - 0
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October 2012
© Diodes Incorporated
A Product Line of
Diodes Incorporated
PAM2863
Functional 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 Voltage Range
LX, I
SENSE
Pin Voltage
VSET Pin Voltage
Maximum Junction Temperature
Storage Temperature
Soldering Temperature
Rating
-0.3 to +40
-0.3 to +40
-0.3 to +6.0
170
-65 to +170
300, 5sec
Unit
V
°C
Recommended Operating Conditions
(@T
A
= +25°C, unless otherwise specified.)
Parameter
Input Voltage Range
Ambient Temperature Range
Junction Temperature Range
Rating
4.5 to 40
-40 to +85
-40 to +125
Unit
V
°C
°C
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© Diodes Incorporated
PAM2863
Document number: DSxxxxx Rev. 1 - 0
A Product Line of
Diodes Incorporated
PAM2863
Thermal Information
Parameter
Thermal Resistance (Junction to Ambient)
Thermal Resistance (Junction to Case)
Package
SOP-8(EP)
SOP-8(EP)
Symbol
θ
JA
θ
JC
Max
90
11
Unit
°C/W
Electrical Characteristics
(@T
A
= +25°C, V
IN
= 16V, unless otherwise specified.)
Parameter
Inout Voltage
Output Current
Shutdown Current
Quiescent Current without Switching
Mean Current Sense Threshold Voltage
Sense Threshold Hysteresis
ISENSE Pin Input Current
VSET Range on VSET Pin
DC Voltage on VSET Pin to Enable
DC Voltage on VSET Pin to Disable
LX Switch on Resistance
LX Switch Leakage Current
Soft-Start Time
Operating Frequency
Recommended Minimum Switch ON Time
Recommended Maximum Switch Frequency
Max Duty Circle
Recommended Duty Cycle Range
Internal Comparator Propagation Delay
Over Temperature Protection
Temp Protection Hysteresis
Current Limit
Note:
Symbol
V
IN
I
LED
I
SD
I
Q
V
SENSE
V
SENSE_HYS
I
SENSE
V
EN
V
EN(ON)
V
EN(OFF)
R
LX
I
LX(LEAK)
T
SS
F
LX
T
ON_REC
F
LX(MAX)
R
S
= 0.1Ω
Test Conditions
Min
4.5
Typ
1
2
20
0.6
Max
40
Units
V
A
A
R
S
= 0.05Ω
VSET Pin Grounded
VSET Pin Floating, V
IN
= 16V
Measured on I
SENSE
Pin with
Respect to V
IN
V
SENSE
= V
IN
-0.1
For DC Dimming
V
EN
Rising
V
EN
Falling
@I
LX
= 100mA
V
IN
= 16V, C
EN
= 1nF
V
IN
= 16V, V
O
= 9.6V (3 LEDs),
L = 47µH,
ΔI
= 0.25A (I
LED
= 1A)
For 4% Accuracy
0.3
95
40
µA
mA
100
±13
8
105
mV
%
µA
2.5
0.25
0.2
0.3
5
1.5
233
500
1.0
98
V
V
V
Ω
µA
Ms
kHz
Ns
MHz
%
%
Ns
°C
°C
A
D
LX
T
PD
(Note 1)
T
OTP
T
OTP_HYS
I
XL(MAX)
Peak Inductor Current
25
45
150
40
2.5
75
1. V
SENSE
: LevelA: 95mV to 100mV; level B: 100mV to 105mV
Parameters are not tested at production, but guaranteed by design.
PAM2863
Document number: DSxxxxx Rev. 1 - 0
4 of 11
www.diodes.com
October 2012
© Diodes Incorporated
A Product Line of
Diodes Incorporated
PAM2863
Typical Performance Characteristics
(@T
A
= +25°C, V
IN
= 16V, unless otherwise specified.)
PAM2863
Document number: DSxxxxx Rev. 1 - 0
5 of 11
www.diodes.com
October 2012
© Diodes Incorporated
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