參數(shù)資料
型號(hào)： MAX1778
廠商： Maxim Integrated Products, Inc.
英文描述： 32-Bit Digital Signal Controller with ROM 100-LQFP -40 to 85
中文描述： 四路輸出、TFT LCD DC-DC轉(zhuǎn)換器，帶有緩沖器
文件頁數(shù)： 34/38頁
文件大?。?/td> 1051K
代理商： MAX1778
M
Quad-Output TFT LCD DC-DC
Converters with Buffer
34
______________________________________________________________________________________
converter steps up the input voltage so that the linear
regulator will not drop out. Therefore, to guarantee that
the external pass transistor does not saturate, the step-
up converter
’
s output voltage must be set above the lin-
ear regulator
’
s output voltage plus the transistor
’
s
saturation rating (V
MAIN
≥
V
LDO
+ V
SAT
).
Power-Up Sequencing and Fault Protection
The MAX1778/MAX1880
–
MAX1885
’
s fault protection
cannot be activated until the power-up sequence is
successfully completed and the power ready output
goes low. Therefore, faults on the main output or posi-
tive charge-pump output could damage the controller
or external components. Additional fault protection may
be added as shown in Figure 10. The external MOSFET
and PNP transistor isolate the positive outputs during
startup. When the controller finishes the power-up
sequence, the power-ready output goes low, turning on
the PNP transistor. Any fault on the positive charge-
pump output will pull down the charge pump
’
s output
voltage and trigger the fault protection; otherwise, the
MOSFET
’
s gate slow charges. Once the MOSFET turns
on, any faults on the main step-up converter
’
s output
will pull down the main output voltage and trigger the
fault protection.
VCOM Buffer Startup
The VCOM buffer does not include soft-start. Therefore,
once the VCOM buffer turns on, it draws high surge
currents while charging the output capacitance. In
some applications, the buffer
’
s high startup surge
current could potentially trip the fault detection circuit,
forcing the controller to shut down. In these cases,
adding a soft-start resistive divider between SUPB and
BUFOUT reduces the startup surge current and voltage
drops associated with this load (Figure 11), as shown in
IN
SHDN
SYSTEM
POSITIVE
V
POS(SYS)
= 20V
STARTUP
POSITIVE
V
POS(START)
= 20V
INPUT
V
IN
= 3.3V
SUPP
LX
L1
6.8
μ
H
INPUT
V
IN
= 3.3V
C1
0.22
μ
F
C5
1.0
μ
F
C7
1.0
μ
F
Q2
Q3
C
OUT
(2) 3.3
μ
F
C4
0.1
μ
F
C
IN
4.7
μ
F
R10
100k
R
RDY
5.1k
R1
274k
R2
49.9k
R7
10k
FB
RDY
TGND
FBP
DRVP
GND
REF
FLTSET
INTG
PGND
C
REF
0.22
μ
F
MAX1778
C8
3.3
μ
F
SYSTEM MAIN
V
MAIN(SYS)
= 8V
STARTUP MAIN
V
MAIN(START)
= 8V
C10
0.1
μ
F
C6
0.1
μ
F
R8
100k
R3
750k
R4
49.9k
R9
30k
Figure 10. Power-Up Sequencing and Fault Protection;
相關(guān)PDF資料
PDF描述
MAX1880 Quad-Output TFT LCD DC-DC Converters with Buffer
MAX1881 Quad-Output TFT LCD DC-DC Converters with Buffer
MAX1882 Quad-Output TFT LCD DC-DC Converters with Buffer
MAX1883 Quad-Output TFT LCD DC-DC Converters with Buffer
MAX1884 Quad-Output TFT LCD DC-DC Converters with Buffer
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX1778EUG 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT
MAX1778EUG+ 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 Quad-Output TFT LCD w/Buffer RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT
MAX1778EUG+T 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 Quad-Output TFT LCD w/Buffer RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT
MAX1778EUG-T 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT
MAX1778EVKIT 功能描述:電源管理IC開發(fā)工具 MAX1778/80/81/82 Eval Kit RoHS:否 制造商:Maxim Integrated 產(chǎn)品:Evaluation Kits 類型:Battery Management 工具用于評估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。

采購需求

(若只采購一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購

我的聯(lián)系方式

*
*
*