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参数资料
| 型号： | MAX1620EEE |
| 厂商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分类： | 稳压器 |
| 英文描述： | Digitally Adjustable LCD Bias Supplies |
| 中文描述： | SWITCHING CONTROLLER, 200 kHz SWITCHING FREQ-MAX, PDSO16 |
| 封装： | 0.150 INCH, 0.025 INCH PITCH, QSOP-16 |
| 文件页数： | 17/20页 |
| 文件大小： | 253K |
| 代理商： | MAX1620EEE |
M
Digitally Adjustable LCD Bias S upplies
______________________________________________________________________________________
17
COMPANY
PART
Coilcraft
(847) 639-6400
DO1608
COMMENTS
SIZE IN mm (H x W x L)
μH RANGE
CD43
Up to 68μH
3.2 x 4 diameter
Up to 1mH
3.18 x 4.45 x 6.6
CD54
Up to 220μH
4.5 x 5.2 diameter
Sumida
USA (847) 956-0666
J apan 81-3-3607-5111
CDRH62B
Up to 330μH
TDK
(847) 390-4373
DT1608
Up to 400μH
3.18 x 4.45 x 6.6
Shielded
3 x 6.2 x 6.2
Shielded
NLC565050
Up to 1mH
5 x 5 x 5.6
TPF0410
Up to 1mH
4 diameter x 10 L
Leaded coil
Table 6. Inductor List
LCDON
typically drives an external PNP transistor,
switching a positive V
OUT
to the LCD. R7 limits the base
current in the PNP; R6 turns off the PNP when
LCDON
is
floating. R6 and R7 can be the same value. Choose R7
such that the minimum base current is greater than 1/50
of the collector current. For example, assume V
OUT,MIN
= 12.5V and I
LCD
= 10mA, then determine R7 as follows:
R7
≤
50 x (12.5 - 0.7) / 10mA = 59k
Remember that LCD voltage is the regulated output volt-
age minus the drop across the PNP switch. The drop
across the external transistor (typically 300mV) must be
accounted for.
If a PFET is preferred for the
LCDON
switch, R6 and R7
in Figure 4 may both be raised to 1M
or more to reduce
operating current. Be sure to choose a P
FET
with ade-
quate breakdown voltage. Since load current is typically
on the order of 10mA, an on-resistance of 10
or less is
usually adequate.
Choosing an Inductor
Practical inductor values range from 33μH to 1mH;
however, 100μH is a good choice for a wide range of
applications. Inductors with a ferrite core or equivalent
are recommended. The inductor’s current rating should
exceed the peak current as set by the k-factor and the
coil inductance; however, for most inductor types, the
coil’s specified current can be exceeded by 20% with
no impact on efficiency.
The peak current is set by the coil inductance as follows:
I
PK
= k-factor / L
and
If we assume that V
BATT,MIN
= 5.3V, V
OUT,MAX
=
25V, I
OUT,MIN
= 15mA, and a minimum k-factor of
16μs-V, then the required I
PK
is:
I
PK
= 2 x 15mA x 25 / 5.3 = 142mA
and
L
≤
= 16μs-V / 142mA = 113μH
The next-lowest practical inductor value is 100μH. Its
current rating must be:
24μs-V (maximum k-factor) / 100μH = 240mA
Table 5 summarizes the minimum inductance value
needed to provide various output currents at several
minimum input voltages. Table 6 lists some suitable coil
types and manufacturers, but is not intended to be a
complete list.
I
1
2
I
V
/ V
OUT,MIN
PK
BATT,MIN
OUT,MAX
=
×
×
1.8V
2.7V
3.6V
5.4V
7.2V
12V
IOUT
5mA
100μH
150μH
220μH
330μH
390μH
680μH
10mA
56μH
82μH
100μH
150μH
220μH
330μH
20mA
27μH
39μH
56μH
82μH
100μH
180μH
30mA
18μH
27μH
33μH
56μH
68μH
120μH
V
BATT,MIN
Table 5. Maximum Inductance vs. I
OUT
and V
BATT,MIN
(20V output)
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1620EEE+ | 功能描述:其他电源管理 Digitally Adjustable LCD Bias Supply RoHS:否 制造商:Texas Instruments 输出电压范围: 输出电流:4 mA 输入电压范围:3 V to 3.6 V 输入电流: 功率耗散: 工作温度范围:- 40 C to + 110 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-48 封装:Reel |
| MAX1620EEE+T | 功能描述:LCD 驱动器 Digitally Adjustable LCD Bias Supply RoHS:否 制造商:Maxim Integrated 数位数量:4.5 片段数量:30 最大时钟频率:19 KHz 工作电源电压:3 V to 3.6 V 最大工作温度:+ 85 C 最小工作温度:- 20 C 封装 / 箱体:PDIP-40 封装:Tube |
| MAX1620EEE-T | 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX1620EPE+ | 制造商:Maxim Integrated Products 功能描述:- Rail/Tube |
| MAX1620ESE+ | 制造商:Maxim Integrated Products 功能描述:- Rail/Tube |
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