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零件编号 | BD9486F | ||
描述 | LED Drivers | ||
制造商 | ROHM Semiconductor | ||
LOGO | |||
1 Page
Datasheet
LED Drivers for LCD Backlights
1ch Boost up type
White LED Driver for large LCD
BD9486F
1.1 General Description
BD9486F is a high efficiency driver for white LEDs and is
designed for large LCDs. BD9486F has a boost DCDC
converter that employs an array of LEDs as the light
source.
BD9486F has some protect functions against fault
conditions, such as over-voltage protection (OVP), over
current limit protection of DCDC (OCP), LED OCP
protection, and Over boost protection (FBMAX).
Therefore it is available for the fail-safe design over a
wide range output voltage.
Key Specifications
Operating power supply voltage range:9.0V to 18.0V
Oscillator frequency of DCDC: 150kHz (RT=100kΩ)
Operating Current:
2.6mA(Typ.)
Operating temperature range:
-40°C to +85°C
1.2 Package(s)
SOP16
W(Typ) x D(Typ) x H(Max)
10.00mm x 6.20mm x 1.71mm
Pin pitch 1.27mm
Features
DCDC converter with current mode
VOUT discharge function at shutdown
LED protection circuit (Over boost protection, LED
OCP protection)
Over-voltage protection (OVP) for the output voltage
Vout
Adjustable soft start
Adjustable oscillation frequency of DCDC
Wide range of analog dimming 0.2V to 3.0V
UVLO detection for the input voltage of the power
stage
Figure 1. SOP16
Applications
TV, Computer Display, LCD Backlighting
1.3 Typical Application Circuit(s)
Figure 2. Typical Application Circuit
○Product structure:Silicon monolithic integrated circuit
.www.rohm.com
© 2013 ROHM Co., Ltd. All rights reserved.
TSZ22111・14・001
○This product has not designed protection against radioactive rays
1/34
TSZ02201-0F1F0C100240-1-2
13.Feb.2014 Rev.004
http://www.Datasheet4U.com
BD9486F
●2.4 Typical Performance Curves (Reference data)
Datasheet
Figure 7. Circuit current (active)
Figure 8. Fsw vs RT characteristic
Figure 9. FB sink current vs FB voltage characteristic
Figure 10. FB source current vs FB voltage characteristic
Figure 11. ISENSE feedback voltage vs ADIM voltage characteristic
www.rohm.com
© 2013 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
8/34
TSZ02201-0F1F0C100240-1-2
13.Feb.2014 Rev.004
http://www.Datasheet4U.com
BD9486F
【setting example】
Above equation is translated as follows.
RVCC [Ω]
VIN [V] 9 [V]
ICC [A] IDCDC [A] IREG [A]
When VIN=12V, ICC=2.0mA, RREG=10kΩand IDCDC=2mA, RVCC’s value is calculated as follows.
RVCC []
0.002 [A]
12 [V] 9 [V]
0.002 [A] 5.0 [V] 1 0000 []
667 []
(ICC is 2.6mA(typ.)) . Please set each values with tolerance and margin.
Datasheet
●3.2.4 LED current setting
LED current can be adjusted by setting the resistance RS [Ω] which connects to ISENSE pin and ADIM[V].
Relationship between RS and ILED current
With DC dimming (ADIM<3.0V)
RISENSE
1
3
ADIM[V] [Ω]
ILED [ A ]
Without DC dimming (ADIM>3.0V)
RISENSE
1.015[V] [Ω]
ILED [ A ]
【setting example】
If ILED current is 200mA and ADIM is 2.0V, we can calculate RISENSE as below.
RISENSE
1
3
ADIM[V]
ILED [A]
1
3
2.0[V]
0.2[A]
3.33[Ω]
Figure 24. LED current setting example
●3.2.5 DCDC Oscillation Frequency Setting
RRT which connects to RT pin sets the oscillation frequency fSW of DCDC.
○Relationship between frequency fSW and RT resistance (ideal)
R RT
15000
fSW [kHz ]
[k ]
【setting example】
When DCDC frequency fsw is set to 200kHz, RRT is as follows.
RRT
15000
fsw [kHz]
15000
200[kHz]
75
[k]
Figure 25. RT terminal setting example
www.rohm.com
© 2013 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
16/34
TSZ02201-0F1F0C100240-1-2
13.Feb.2014 Rev.004
http://www.Datasheet4U.com
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页数 | 30 页 | ||
下载 | [ BD9486F.PDF 数据手册 ] |
零件编号 | 描述 | 制造商 |
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