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Электронный компонент: FAN5607

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www.fairchildsemi.com
REV. 1.0.0 6/22/04
Features
Parallel LED Driver Supports all Forward Voltages
Adaptive V
OUT
Adjustment to the Highest Diode Voltage
Internally Matched LED Current Sources
Built-in Charge Pump has Three Modes of Operation:
1X, 1.5X, and 2X Mode
Up to 93% Efficiency
Low EMI, Low Ripple
Up to 120mA Output Current (
)
External Resistor to Set Maximum (100%) LED Current
Enable Input Can be Duty-Cycle-Modulated to Control
LED Current Level Between 0 and 100%
2.4V to 5.5V Input Voltage Range
I
CC
< 1A in Shutdown Mode
1MHz Operating Frequency
Shutdown Isolates Output from Input
Soft-Start Limits Inrush Current
Short Circuit Protection
Minimal External Components Needed
Available in a 4x4mm 16-lead MLP Package
Applications
Cell Phones
Handheld Computers
PDA, DSC, MP3 Players
Keyboard Backlight
LED Displays
Description
The FAN5607 generates regulated output current from a bat-
tery with input voltage varying between 2.7V to 5.5V.
Switch reconfiguration and fractional switching techniques
are utilized to achieve high efficiency over the entire input
voltage range. A proprietary internal circuitry continuously
monitors each LED current loop and automatically adjusts
the generated output DC voltage to the lowest minimum
value required by the LED having the highest forward volt-
age. This adaptive nature of the FAN5607 eliminates the
need for LED pre-selection (matching) and ensures opera-
tion at high efficiency. When the input voltage is sufficiently
high to sustain the programmed current level in the LEDs,
the FAN5607 re-configures itself to operate as a linear regu-
lator, and the DC-DC converter is turned off. Only two 0.1F
to 1F bucket capacitors and two 4.7F input/output capaci-
tors are needed for proper operation. LED current can be
programmed using an external resistor. The resistor sets the
maximum LED current and a PWM signal applied to the
enable pin can modulate that current level between 0mA
(off) and the maximum level.
Soft-start circuitry prevents excessive current draw during
power on. The device has built-in short circuit protection.
The device is available in 4x4mm 16-lead MLP package.
4
30
mA
FAN5607
LED Driver with Adaptive Charge Pump DC/DC
Converter
Typical Application
CAP1
CAP2
C
OUT
C
IN
LED-
LED-
LED-
LED-
EN
V
OUT
V
OUT
V
IN
V
IN
R
SET
R
SET
GND
FAN5607
CAP+
CAP+
CAP-
CAP-
2
REV. 1.0.0 6/22/04
FAN5607
PRODUCT SPECIFICATION
Definition of Terms
Output Current Accuracy:
reflects the difference between the measured value of the output current (LED) and
programmed value of this current
.
Current Matching:
refers to the absolute value of difference in current between the two LED branches.
Efficiency:
is expressed as a ratio between the electrical power into the LEDs and the total power consumed from the input
power supply.
Note:
1. Some competitors calculate the power efficiency as a function of V
OUT
instead of V
LED
. This method neglects the power lost
due to the cathode
and provides an efficiency "improved" up to 5%.
Output Current Accuracy (%)
I
OUT
measured
I
OUT
programmed
(
) 100
I
OUT
programmed
--------------------------------------------------------------------------------------------------------------------
=
Current Matching (%)
I
LED
branch 1
I
LED
branch 2
(
) 100
I
LED
branch 1
I
LED
branch 2
+
(
)
-----------------------------------------------------------------------------------------------------
=
Efficiency
V
LEDi
I
LEDi
i
1
=
4
V
IN
I
IN
--------------------------------------------
=
voltage
0
PRODUCT SPECIFICATION
FAN5607
REV. 1.0.0 6/22/04
3
CAP2-
4x4mm 16-Lead MLP
FAN5607
Top-View
GND
CAP2+
CAP1-
NC
EN
NC
NC
V
OUT
V
IN
CAP1+
R
SET
LED-
LED-
LED-
LED-
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Pin Assignments
Pin Descriptions
Test Circuit
Pin No.
Pin Name
Pin Function Description
1
EN
Enable Pin
2
NC
No Connection
3
NC
No Connection
4
NC
No Connection
5
R
SET
External resistor to set LED current
6
V
OUT
Output to LEDs Anode
7
V
IN
Input
8
CAP1+
Bucket capacitor positive connection
9
CAP1-
Bucket capacitor negative terminal
10
CAP2-
Bucket capacitor negative connection
11
CAP2+
Bucket capacitor positive terminal
12
GND
Ground
13
LED-
4th LED Cathode
14
LED-
3rd LED Cathode
15
LED-
2nd LED Cathode
16
LED-
1st LED Cathode
EN
NC
NC
NC
CAP2
1
F
CAP1
1
F
V
IN
= 2.7V to 5.5V
C
IN
4.7
F
V
OUT
C
OUT
4.7
F
R
SET
4 White LEDs
Fairchild QTLP670C-IW
Super Bright LED
1
4
5
8
9
16
13
12
FAN5607
All capacitors are Ceramic chip capacitors
To V
OUT
Pin
Figure 1. Test Circuit
4
REV. 1.0.0 6/22/04
FAN5607
PRODUCT SPECIFICATION
Absolute Maximum Ratings
(
Note 2)
Recommended Operating Conditions
Note:
2. Operation beyond the absolute maximum ratings may cause damage to device.
3. Using Mil Std. 883E, method 3015.7(Human Body Model) and EIA/JESD22C101-A (Charge Device Model)
Parameter
Min
Max
Unit
V
IN
, V
OUT
Voltage to GND
-0.3
6.0
V
Any other Pin Voltage to GND
-0.3
V
IN
+ 0.3
V
Power Dissipation
Internally
Limited
Lead Soldering Temperature (10 seconds)
300
C
Operating Junction Temperature Range
150
C
Storage Temperature
-55
150
C
Electrostatic Discharge Protection Level (Note 3)
HBM
4
kV
CDM
2
Parameter
Min
Typ
Max
Unit
Input Voltage Range, V
IN
2.4
5.5
V
Operating Ambient Temperature Range
-40
25
85
C
LED Forward Voltage
4
V
Current through each LED
2
30
mA
PRODUCT SPECIFICATION
FAN5607
REV. 1.0.0 6/22/04
5
Electrical Characteristics
V
IN
= 2.7V to 5.5V, T
A
= -40C to +85C, Test Circuit Figure 1, Unless otherwise noted.
Typical values are at T
A
= 25C
Parameter
Conditions
Min.
Typ.
Max.
Units
Input Undervoltage Lockout
1.7
1.8
2.3
V
I
LED
Accuracy
5
%
Current Matching
3
%
Output Voltage (V
OUT
= V
f
+ V
Cathode
)
LED V
f
= 3.5V
3.62
V
Quiescent Current, I
Q
V
IN
= 5.5V,
I
OUT
= 0mA
130
400
A
Shutdown Supply Current
V
EN
= 0V
1
A
Output Short Circuit Current
V
IN
= 5.5V,
V
OUT
= 0V
65
mA
V
OUT
Over Voltage Protection
5.1
V
V
IN
At Mode Transition From 1X to 1.5X
LED V
f
= 3.5V,
I
OUT
= 4 x 20mA
3.76
V
V
IN
At Mode Transition From 1.5X to 2X
LED V
f
= 3.5V,
I
OUT
= 4 x 20mA
2.85
V
Peak Efficiency
V
IN
= 3.75V,
LED V
f
= 3.5V,
I
LED
= 20mA
93
%
Oscillator Frequency
0.8
1
1.2
MHz
Thermal Shutdown Threshold
145
C
Thermal Shutdown Hysteresis
15
C
EN Logic Input High Voltage
1.6
V
EN Logic Input Low Voltage
0.4
V
EN Input Bias Current
EN to V
IN
or GND
-1
1
A
I
LED
20mA
I
LED
20mA