- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄375724 > FAN5235 (FAIRCHILD SEMICONDUCTOR CORP) System Electronics Regulator for Mobile PCs PDF資料下載
參數(shù)資料
| 型號(hào)： | FAN5235 |
| 廠商： | FAIRCHILD SEMICONDUCTOR CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | System Electronics Regulator for Mobile PCs |
| 中文描述： | SWITCHED CAPACITOR REGULATOR, 345 kHz SWITCHING FREQ-MAX, PDSO24 |
| 封裝： | QSOP-24 |
| 文件頁(yè)數(shù)： | 12/15頁(yè) |
| 文件大小： | 85K |
| 代理商： | FAN5235 |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)當(dāng)前第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)
FAN5235
12
REV. 1.3.3 1/3/02
MOSFET Selection
The notebook application circuit shown in Figure 1 is designed
to run with an input voltage operating range of 5.4-24V.
This wide input range helps determine the selection of the
MOSFETs for the 3.3V and 5V converters, since the high-side
MOSFET is on (V
out
/ V
in
) of the time, and the low-side
MOSFET 1 – (V
out
/ V
in
) of the time. The maxima and minima
are tabulated in Table 2:
Table 2. MOSFET Duty Cycles
High-side FET
Low-side FET
All four MOSFETs have maximum duty cycles greater than
50%. Thus, it is necessary to size all four approximately the
same.
3.3V and 5V Schottky Selection
The maximum current at which the converters operate in PFM
mode determines selection of a Schottky. In the application
shown in Figure 8, since the transition can occur at a current as
high as 28mV * (17.5K
/ 10K
) / 35m
= 1.4A, the diode
(with 24V input) will be conducting 86% of the period (from
Table 2). It thus has an average current of 1.4A * 0.86 = 1.2A,
which requires a Schottky current rating >1A.
3.3V and 5V Inductor Selection
See Table 1.
3.3V and 5V Output Cap Selection
See Table 1.
12V Component Selection
Calculation of the inductor, diode and output capacitor for the
+12V output fly-back is complex, depending on output power
and efficiency. See Applications Bulletin AB-19 for an Excel
spreadsheet calculation tool. See Table 1 also.
Input Capacitor Selection
Input capacitor selection is determined by ripple current rating.
With two converters operating in parallel at differing duty
cycles, calculation of input ripple current is complex; see
Applications Bulletin AB-19 for an Excel spreadsheet
calculation tool.
V
out
3.3V
5V
V
in
5.4V
.61
.43
24V
.14
.21
V
out
3.3V
5V
V
in
5.4V
.39
.07
24V
.86
.79
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| FAN5236MTC | Dual Mobile-Friendly DDR / Dual-output PWM Controller |
| FAN5236MTCX | Dual Mobile-Friendly DDR / Dual-output PWM Controller |
| FAN5236QSC | Dual Mobile-Friendly DDR / Dual-output PWM Controller |
| FAN5236QSCX | Dual Mobile-Friendly DDR / Dual-output PWM Controller |
| FAN5236 | Dual Mobile-Friendly DDR / Dual-output PWM Controller |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| FAN5235_CAB3026B WAF | 制造商:Fairchild Semiconductor Corporation 功能描述: |
| FAN5235_CAB3116B WAF | 制造商:Fairchild Semiconductor Corporation 功能描述: |
| FAN5235MTC | 功能描述:DC/DC 開(kāi)關(guān)控制器 Regulator System Electronics RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開(kāi)關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK |
| FAN5235MTC_Q | 功能描述:DC/DC 開(kāi)關(guān)控制器 Regulator System Electronics RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開(kāi)關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK |
| FAN5235MTCX | 功能描述:DC/DC 開(kāi)關(guān)控制器 Regulator System Electronics RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開(kāi)關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。