- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄30767 > LT3641EUFD#TRPBF (LINEAR TECHNOLOGY CORP) 3.4 A DUAL SWITCHING CONTROLLER, 2350 kHz SWITCHING FREQ-MAX, PQCC28 PDF資料下載
參數(shù)資料
| 型號： | LT3641EUFD#TRPBF |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 3.4 A DUAL SWITCHING CONTROLLER, 2350 kHz SWITCHING FREQ-MAX, PQCC28 |
| 封裝： | 4 X 5 MM, LEAD FREE, PLASTIC, MO-220, QFN-28 |
| 文件頁數(shù)： | 4/28頁 |
| 文件大?。?/td> | 416K |
| 代理商： | LT3641EUFD#TRPBF |
第1頁第2頁第3頁當(dāng)前第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁
LT3641
12
3641f
Setting the Output Voltages
The internal reference voltage is 1.265V for the high
voltage channel, and 600mV for the low voltage channel.
The output voltages are set by resistor dividers according
to the following formulas:
R2
= R1
VOUT1
1.265V
1
R4
= R3
VOUT2
0.6V
1
Use 1% resistors in the resistor dividers. To avoid noise
problems, R1 should be 100k or less, and R3 should
be 50k or less. Reference designators refer to the Block
Diagram.
Switching Frequency
The LT3641 uses a constant-frequency PWM architecture
that can be programmed to switch from 350kHz to 2.2MHz
by using a resistor tied from the RT pin to ground. Table
1 shows the necessary RT value for a desired switching
frequency.
Table 1. Switching Frequency vs RT Value
SWITCHING FREQUENCY (MHz)
RT (k)
0.35
267
0.5
182
1
82.5
2
32.4
2.2
27.4
Selection of the operating frequency is mainly a trade-off
between efciency and component size. The advantage
of high frequency operation is that smaller inductor and
capacitor values may be used. The disadvantage is lower
efciency.
APPLICATIONS INFORMATION
The high switching frequency also decreases the duty
cycle range. The reason is that the LT3641 switches have
nite minimum on- and off-times independent of the
switching frequency. The top switch in the high voltage
channel can turn on for a minimum of ~60ns and turn off
for a minimum of ~70ns. The top switch in the low voltage
channel can turn on for a minimum of ~110ns and turn
off for a minimum of ~70ns. The minimum and maximum
duty cycles are:
DCMIN = fS tON(MIN)
DCMAX = 1 – fS tOFF(MIN)
where fSistheswitchingfrequency,tON(MIN)istheminimum
switch on-time, and tOFF(MIN) is the minimum switch
off-time. These equations illustrate how duty cycle range
increases when switching frequency decreases.
The internal oscillator of the LT3641 can be synchronized
to an external 350kHz to 2.5MHz positive clock signal on
the SYNC pin. The RT value should be chosen such that
the internal oscillator’s frequency is 20% lower than the
lowest SYNC clock frequency (refer to Table 1). To avoid
erratic operation, the LT3641 ignores the SYNC signal
until the FB1 pin voltage is above 1.165V. When applying
a SYNC signal, the rising edges reset the LT3641’s internal
clock and initiate a switch cycle. The amplitude of the
SYNC signal must be at least 2V. The SYNC pulse width
must be at least 40ns.
VIN Voltage Range
The LT3641’s minimum operating voltage is 3.6V typical.
A higher minimum operating voltage can be accurately
programmed with a resistor divider between the VIN pin
and the EN/UVLO pin. The EN/UVLO threshold is 1.26V.
When the LT3641 is enabled, a 2μA current ows out of the
EN/UVLO pin generating hysteresis to prevent the switching
action from falsely disabling the LT3641. Choose the divider
resistances for appropriate hysteresis voltage.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LT3641IUFD#PBF | 3.4 A DUAL SWITCHING CONTROLLER, 2350 kHz SWITCHING FREQ-MAX, PQCC28 |
| LT3653EDCB#TRPBF | 1.2 A BATTERY CHARGE CONTROLLER, 1650 kHz SWITCHING FREQ-MAX, PDSO8 |
| LT3684IMSE | 4 A SWITCHING REGULATOR, 3300 kHz SWITCHING FREQ-MAX, PDSO10 |
| LT3684EDD#TR | 4 A SWITCHING REGULATOR, 3300 kHz SWITCHING FREQ-MAX, PDSO10 |
| LT3694-1EUFD#PBF | 2.6 A SWITCHING REGULATOR, 2500 kHz SWITCHING FREQ-MAX, PQCC28 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LT3641HFE#PBF | 功能描述:IC REG BUCK SYNC ADJ DL 28TSSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 設(shè)計(jì)資源:Design Support Tool 標(biāo)準(zhǔn)包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開關(guān):- 電流 - 輸出:100mA 同步整流器:是 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-5 細(xì)型，TSOT-23-5 包裝:剪切帶 (CT) 供應(yīng)商設(shè)備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT |
| LT3641HFE#TRPBF | 功能描述:IC REG BUCK SYNC ADJ DL 28TSSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 設(shè)計(jì)資源:Design Support Tool 標(biāo)準(zhǔn)包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開關(guān):- 電流 - 輸出:100mA 同步整流器:是 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-5 細(xì)型，TSOT-23-5 包裝:剪切帶 (CT) 供應(yīng)商設(shè)備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT |
| LT3641IFE#PBF | 功能描述:IC REG BUCK SYNC ADJ DL 28TSSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 設(shè)計(jì)資源:Design Support Tool 標(biāo)準(zhǔn)包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開關(guān):- 電流 - 輸出:100mA 同步整流器:是 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-5 細(xì)型，TSOT-23-5 包裝:剪切帶 (CT) 供應(yīng)商設(shè)備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT |
| LT3641IFE#TRPBF | 功能描述:IC REG BUCK SYNC ADJ DL 28TSSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 設(shè)計(jì)資源:Design Support Tool 標(biāo)準(zhǔn)包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開關(guān):- 電流 - 輸出:100mA 同步整流器:是 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-5 細(xì)型，TSOT-23-5 包裝:剪切帶 (CT) 供應(yīng)商設(shè)備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT |
| LT3641IUFD#PBF | 功能描述:IC REG BUCK SYNC ADJ DL 28QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 設(shè)計(jì)資源:Design Support Tool 標(biāo)準(zhǔn)包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開關(guān):- 電流 - 輸出:100mA 同步整流器:是 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-5 細(xì)型，TSOT-23-5 包裝:剪切帶 (CT) 供應(yīng)商設(shè)備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。