參數(shù)資料
型號(hào)： MAX1542ETP
廠商： MAXIM INTEGRATED PRODUCTS INC
元件分類： 穩(wěn)壓器
英文描述： TFT LCD DC-to-DC Converter with Operational Amplifiers
中文描述： 1.8 A SWITCHING REGULATOR, 1400 kHz SWITCHING FREQ-MAX, PQCC20
封裝： 5 X 5 MM, 0.8 MM HEIGHT, EXPOSED PAD, TQFN-20
文件頁(yè)數(shù)： 17/20頁(yè)
文件大小： 506K
代理商： MAX1542ETP
M
TFT LCD DC-to-DC Converter with
Operational Amplifiers
______________________________________________________________________________________
17
negative charge-pump output voltages for a given
V
MAIN
for one-, two-, and three-stage charge pumps,
based on the following equations:
where G_ON is the positive charge-pump output volt-
age, G_OFF is the negative charge-pump output volt-
age, n is the number of charge-pump stages, and V
D
is
the voltage drop across each diode.
V
D
is the forward voltage drop of the charge-pump
diodes.
Flying Capacitors
Increasing the flying capacitor (C3, C4, and C5) value
increases the output current capability. Increasing the
capacitance indefinitely has a negligible effect on out-
put current capability because the internal switch resis-
tance and the diode impedance limit the source
impedance. A 0.1μF ceramic capacitor works well in
most low-current applications. The flying capacitor
’
s
voltage rating must exceed the following:
V
CX
> n
V
MAIN
Where n is the stage number in which the flying capaci-
tor appears, and V
MAIN
is the main output voltage. For
example, the two-stage positive charge pump in the
Typical Application Circuits
(Figures 1 and 2) where
V
MAIN
= 8V contains two flying capacitors. The flying
capacitor in the first stage (C5) requires a voltage rat-
ing greater than 8V. The flying capacitor in the second
stage (C4) requires a voltage rating greater than 16V.
Charge-Pump Output Capacitor
Increasing the output capacitance or decreasing the
ESR reduces the output ripple voltage and the peak-to-
peak transient voltage. With ceramic capacitors, the
output voltage ripple is dominated by the capacitance
value. Use the following equation to approximate the
required capacitor value:
where V
RIPPLE
is the acceptable peak-to-peak output-
voltage ripple.
Charge-Pump Rectifier Diodes
To maximize the available output voltage, use Schottky
diodes with a current rating equal to or greater than two
times the average charge-pump input current. If the
loaded charge-pump output voltage is greater than
required, some or all of the Schottky diodes can be
replaced with low-cost silicon switching diodes with an
equivalent current rating. The charge-pump input cur-
rent is:
where n is the number of charge-pump stages.
I
I
n
CP IN
_
CP OUT
_
=
×
C
I
F
V
OUT
LOAD
OSC
RIPPLE
≥
×
×
2
G ON
G OFF
_
V
n V
(
V
n V
(
V
MAIN
MAIN
D
MAIN
D
_
)
)
=
+
=
POSITIVE CHARGE-PUMP
OUTPUT VOLTAGE vs. V
MAIN
V
MAIN
(V)
G
12
10
8
6
4
10
20
30
40
50
60
0
2
14
2-STAGE CHARGE-PUMP
3-STAGE CHARGE-PUMP
V
D
= 0.3V TO 1V
1-STAGE CHARGE-PUMP
Figure 5. Positive Charge-Pump Output Voltage vs. V
MAIN
NEGATIVE CHARGE-PUMP
OUTPUT VOLTAGE vs. V
MAIN
V
MAIN
(V)
G
12
10
8
6
4
-40
-35
-30
-25
-20
-15
-10
-5
-0
-45
2
14
1-STAGE
CHARGE-PUMP
2-STAGE
CHARGE-PUMP
3-STAGE
CHARGE-PUMP
V
D
= 0.3V TO 1V
Figure 6. Negative Charge-Pump Output Voltage vs. V
MAIN
相關(guān)PDF資料
PDF描述
MAX1551-MAX1555 SOT23 Dual-Input USB/AC Adapter 1-Cell Li+Battery Chargers
MAX1551 SOT23. Dual-Input. USB/AC Adapter. 1-Cell Li+ Battery Chargers
MAX1555 SOT23. Dual-Input. USB/AC Adapter. 1-Cell Li+ Battery Chargers
MAX1552 Complete Power IC for Low-Cost PDAs
MAX1552ETE Complete Power IC for Low-Cost PDAs
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX1542ETP+ 功能描述:LCD 驅(qū)動(dòng)器 TFT LCD DC/DC Conv w/Op Amps RoHS:否 制造商:Maxim Integrated 數(shù)位數(shù)量:4.5 片段數(shù)量:30 最大時(shí)鐘頻率:19 KHz 工作電源電壓:3 V to 3.6 V 最大工作溫度:+ 85 C 最小工作溫度:- 20 C 封裝 / 箱體:PDIP-40 封裝:Tube
MAX1542ETP+T 功能描述:LCD 驅(qū)動(dòng)器 TFT LCD DC/DC Conv w/Op Amps RoHS:否 制造商:Maxim Integrated 數(shù)位數(shù)量:4.5 片段數(shù)量:30 最大時(shí)鐘頻率:19 KHz 工作電源電壓:3 V to 3.6 V 最大工作溫度:+ 85 C 最小工作溫度:- 20 C 封裝 / 箱體:PDIP-40 封裝:Tube
MAX1542ETP-T 功能描述:LCD 驅(qū)動(dòng)器 RoHS:否 制造商:Maxim Integrated 數(shù)位數(shù)量:4.5 片段數(shù)量:30 最大時(shí)鐘頻率:19 KHz 工作電源電壓:3 V to 3.6 V 最大工作溫度:+ 85 C 最小工作溫度:- 20 C 封裝 / 箱體:PDIP-40 封裝:Tube
MAX1543ETP 功能描述:LCD 驅(qū)動(dòng)器 RoHS:否 制造商:Maxim Integrated 數(shù)位數(shù)量:4.5 片段數(shù)量:30 最大時(shí)鐘頻率:19 KHz 工作電源電壓:3 V to 3.6 V 最大工作溫度:+ 85 C 最小工作溫度:- 20 C 封裝 / 箱體:PDIP-40 封裝:Tube
MAX1543ETP+ 功能描述:LCD 驅(qū)動(dòng)器 TFT LCD DC/DC Conv w/Op Amps RoHS:否 制造商:Maxim Integrated 數(shù)位數(shù)量:4.5 片段數(shù)量:30 最大時(shí)鐘頻率:19 KHz 工作電源電壓:3 V to 3.6 V 最大工作溫度:+ 85 C 最小工作溫度:- 20 C 封裝 / 箱體:PDIP-40 封裝:Tube
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)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(gòu)。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(gòu)。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(gòu)

我的聯(lián)系方式

*
*
*