BELLING BL8040 High efficiency 1.2mhz 30v boost led driver Datasheet

BL8040
High Efficiency 1.2MHz 30V Boost LED Driver
DESCRIPTION
FEATURES
BL8040 is a step-up converter designed for
driving up to 7 series white LED's from a single
cell Lithium Ion battery. Its low 250mV feedback
voltage reduces power loss and improves
efficiency.
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Optimized operation frequency can meet the
requirement of small LC filters value and low
operation current with high efficiency. Internal
soft start function can reduce the inrush current.
Tiny package type provides the best solution for
PCB space saving and total BOM cost.
BL8040 is available in SOT23-6 package that is PB
free.
2.5V to 5.5V Input Voltage
Drivers up to 8 Series WLEDs
Low 250mV Feedback Voltage
1.2MHz Fixed Switching Frequency
Internal 1.6A Switch Current Limit
Internal Compensation
Thermal Shutdown
Over Voltage Protection
Dimming with wide Frequency Range
Available in SOT23-6 Package
APPLICATIONS
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Camera Flash White LED
PDA LED back light
Digital still cameras
TYPICAL APPLICATION
Figure1. BL8040 Typical Application Circuit
ORDERING INFORMATION
MARKING INFORMATION
BL8040 □
1□
2□
3
Code
Description
1
Temperature & Rohs:
2
Package Type:
Marking
B6: SOT-23-6
WL: Product Code
3
Packing Type:
Product Classification
BL8040CB6TR
C: -40~85°C, Pb Free Rohs Std.
YW: Date Code
1
5
4
WLYW
WLYW
TR: Tape & Reel (Standard)
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6
1
2
3
BL8040
PIN DESCRIPTION
Pin No.
Symbol
1
LX
2
3
GND
FB
4
EN
5
OVP
6
IN
Description
Power Switch Output. LX is the drain of the internal MOSFET switch. Connect the
power inductor and output rectifier to LX. LX can swing between GND and 30V.
Ground.
Feedback Input. The FB voltage is 0.25V. Connect a resistor divider to FB.
Chip enable, but a PWM signal with various duty cycle can directly sent to EN pin to
achieve the backlight dimming.
Over Voltage Input. OV measures the output voltage for open circuit protection.
Connect OV to the output at the top of the LED string.
Power Supply. Must be locally bypassed.
ABSOLUTE MAXIMUM RATING
Parameter
IN, EN Pin Voltage
SW Pin Voltage
All Other Pin Voltage
Junction Temperature (TJ)
Ambient Temperature (TA)
Power Dissipation
Thermal Resistance (θJA)
Thermal Resistance (θJC)
Storage Temperature (Ts)
Lead Temperature & Time
Value
-0.3V to 6V
-0.3V to 30V
-0.3V to 6V
150C
-40C to 85C
600mW
250C/W
130C/W
-65C to 150C
260C, 10Sec
SOT23-6
RECOMMENDED WORK CONDITIONS
Parameter
Value
Input Voltage Range
Output Voltage Range
Operating Junction Temperature(Tj)
2.5V to 5.5V
VIN to 30V
-40C –125C
ELECTRICAL CHARACTERISTICS
(Ta=25C, unless otherwise noted)
Symbol
Item
Conditions
Min.
VIN
Operating Input Voltage
2.5
VFB
IFB
Feedback Voltage
FB input Bias Current
SW Leakage
237
-50
IQ
Quiescent Current
FSW
DMAX
VEN
VOVP
Oscillator Frequency
Maximum Duty Cycle
EN Threshold
OVP Threshold
SW On-Resistance
Current Limit
Thermal Shutdown
ILIMIT
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VSW=20V
VFB=0.2V, Switch
VEN=0V
VIN=4V, Duty Cycle = 50%
2
Typ.
250
-10
0.15
0.1
1.2
90
1
28
400
1.6
160
Max.
Unit
5.5
V
263
mV
nA
uA
mA
uA
MHz
%
V
V
mΩ
A
C
1
0.3
1
650
BL8040
TYPICAL PERFORMANCE CHARACTERISTICS
Quiescent Current VS. Supply Voltage
CE pin Bias Current VS. EN pin Voltage
(VCE=0V)
(Vin=VCE)
0.80
0.030
Quiescent Current (uA)
CE Pin Bias Current (uA)
0.70
0.025
0.020
0.015
0.010
0.005
0.60
0.50
0.40
0.30
0.20
0.10
0.000
0.00
0
1
2
3
4
CE Pin Voltage (V)
5
6
0
3
4
5
6
Efficiency VS. Output Current (4LEDS)
250
100
245
90
240
80
235
70
Efficiency (%)
FB Pin Voltage (mV)
2
Supply Voltage (V)
FB Pin Voltage VS. Supply Voltage
230
225
220
215
60
50
40
30
210
20
Vout=18V
205
2
3
4
Supply Voltage (V)
5
Iout=25mA
Iout=60mA
Iout=100mA
10
Vout=15V
200
0
6
2.5
Max. Output Current VS. Output Voltage
1000
700
5.5
250
245
240
FB Pin Voltage (mV)
800
3.5
4.5
Supply Voltage (V)
FB Pin Voltage VS. Supply Voltage
Vin=2.5V
Vin=3.0V
Vin=5.0V
Vin=3.5V
Vin=4.2V
900
Maximum Output Current(mA)
1
600
500
400
300
235
230
225
220
215
200
210
100
205
6串9并
6串8并
200
0
4
10
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16
Output Voltage(V)
22
3.0
28
3
3.5
4.0
4.5
Supply Voltage (V)
5.0
5.5
BL8040
PWM BRIGHTNESS DIMMING CONTROL at EN PIN
When EN pin is forced a PWM signal with frequency higher than 20KHz, the chip is in dimming mode. The internal
circuit changes the feedback voltage according to the duty cycle of the PWM signal. The feedback voltage (Vfb) is
simply defined as below:
Vfb=250mV x Duty Cycle (%)
To shut down the chip, one has to make the EN signal low, and keep its low state for more than 2.5ms.
PACKAGE INFORMATION
Package
SOT-23-6
Devices per reel
Package dimension：
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4
3000Pcs
Unit
mm