参数资料
| 型号： | MAX8709BETI+T |
| 厂商： | Maxim Integrated |
| 文件页数： | 22/24页 |
| 文件大小： | 0K |
| 描述： | IC CNTRLR CCFL HI EFF 28-TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 类型： | CCFL 控制器 |
| 频率： | 25 ~ 300 kHz |
| 电流 - 电源： | 1.5mA |
| 电流 - 输出： | 500mA |
| 电源电压： | 4.6 V ~ 28 V |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 28-WFQFN 裸露焊盘 |
| 供应商设备封装： | 28-TQFN-EP（5x5） |
| 包装： | 带卷 (TR) |
High-Efficiency CCFL Backlight
Controller with SMBus Interface
acceptable fault transient response and does not cause
excessive ringing at the beginning of a DPWM pulse.
for REF, CCV, CCI, and ILIM (if a resistive voltage-
divider is used).
Larger CCV values reduce transient overshoot but can
reduce light output at low-DPWM duty cycles by increasing
the time required to reach the tube strike voltage.
Other Components
The external bootstrap circuits formed by D1 and
C5/C6 in Figure 1 power the high-side MOSFET drivers.
Connect BST1/BST2 through a signal-level silicon
diode to V DD , and bypass it to LX1/LX2 with a 0.1μF
ceramic capacitor.
Layout Guidelines
Careful PC board layout is critical to achieve stable
operation. The high-voltage section and the switching
section of the circuit require particular attention. The
high-voltage sections of the layout need to be well sep-
arated from the control circuit. Most layouts for single-
lamp notebook displays are constrained to the long
and narrow form factor, so this separation occurs natu-
rally. Follow these guidelines for good PC board layout:
1) Keep the high-current paths short and wide, espe-
cially at the ground terminals. This is essential for
stable, jitter-free operation, and high efficiency.
2) Utilize a star-ground configuration for power and
analog grounds. The power and analog grounds
should be completely isolated—meeting only at the
center of the star. The center should be placed at
the exposed backside pad to the QFN package.
Using separate copper islands for these grounds
may simplify this task. Quiet analog ground is used
C2
N1
N2
3)
4)
5)
6)
7)
8)
Route high-speed switching nodes away from sen-
sitive analog areas (CCI, CCV, REF, V FB , I FB , I SEC ,
ILIM). Make all pin-strap control input connections
(ILIM, etc.) to analog ground or V CC rather than
power ground or V DD .
Mount the decoupling capacitor from V CC to GND
as close as possible to the IC with dedicated
traces that are not shared with other signal paths.
The current-sense paths for LX1 and LX2 to GND
must be made using Kelvin-sense connections to
guarantee the current-limit accuracy. With 8-pin
SO MOSFETs, this is best done by routing power
to the MOSFETs from outside using the top copper
layer, while connecting GND and LX inside (under-
neath) the 8-pin SO package.
Ensure the feedback connections are short and
direct. To the extent possible, IFB, VFB, and ISEC
connections should be far away from the high-volt-
age traces and the transformer.
To the extent possible, high-voltage trace clear-
ance on the transformer’s secondary should be
widely separated. The high-voltage traces should
also be separated from adjacent ground planes to
prevent lossy capacitive coupling.
The traces to the capacitive voltage-divider on the
transformer’s secondary need to be widely sepa-
rated to prevent arcing. Moving these traces to
opposite sides of the board can be beneficial in
some cases (see Figure 9).
D1
C4
T1
C3
R2
LAMP
HIGH-CURRENT PRIMARY CONNECTION
NOTE: DUAL MOSFET N2 IS MOUNTED ON THE BOTTOM SIDE OF THE PC BOARD DIRECTLY UNDER N1.
Figure 9. High-Voltage Components Layout Example
HIGH-VOLTAGE SECONDARY CONNECTION
22
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX8709ETI | 功能描述:显示驱动器和控制器 RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel |
| MAX8709ETI+ | 功能描述:显示驱动器和控制器 CCFL Backlight Controller w/SMBus RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel |
| MAX8709ETI+T | 功能描述:显示驱动器和控制器 CCFL Backlight Controller w/SMBus RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel |
| MAX8709ETI-T | 功能描述:显示驱动器和控制器 RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel |
| MAX8709EVKIT | 功能描述:显示开发工具 MAX8709 Eval Kit RoHS:否 制造商:4D Systems 产品:4Display Shields 工具用于评估:?OLED-160-G1, ?OLED-160-G2 接口类型:Serial 工作电源电压:5 V |
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