參數(shù)資料
型號(hào)： LTC3521IUF#PBF
廠商： LINEAR TECHNOLOGY CORP
元件分類： 穩(wěn)壓器
英文描述： SWITCHING REGULATOR, 1350 kHz SWITCHING FREQ-MAX, PQCC24
封裝： 4 X 4 MM, LEAD FREE, PLASTIC, MO-220WGGD, QFN-24
文件頁(yè)數(shù)： 7/22頁(yè)
文件大?。?/td> 1476K
代理商： LTC3521IUF#PBF
LTC3521
15
3521fa
Buck Input Capacitor Selection
ThePVIN2pinprovidescurrenttothebuckconverterpower
switch and is the supply pin for the IC’s internal circuitry.
It is recommended that a low ESR ceramic capacitor with
a value of at least 4.7F be used to bypass this pin. The
capacitor should be placed as close to the pin as possible
and have a short return to ground.
Buck Output Voltage Programming
The output voltage is set by a resistive divider, according
to the following formula:
VOUT2,3 = 0.6V 1+
R2
R1
Theexternaldividerisconnectedtotheoutput,asshownin
Figure 3. It is recommended that a feedforward capacitor,
CFF, be placed in parallel with resistor R2 to improve the
noise immunity of the feedback node. Table 3 provides
the recommended resistor and feedforward capacitor
combinations for common output voltage options.
Table 3. Buck Resistor Divider Values
VOUT
R1
R2
CFF
0.6V
–
0
–
0.8V
200k
69.8k
22pF
1.0V
118k
80.6k
22pF
1.2V
100k
102k
22pF
1.5V
78.7k
121k
22pF
1.8V
68.1k
137k
22pF
2.7V
63.4k
226k
33pF
3.3V
60.4k
274k
33pF
Buck-Boost Output Voltage Programming
The buck-boost output voltage is set by a resistive divider
according to the following formula:
VOUT1 = 0.6V 1+
R2
R1
The external divider is connected to the output, as shown
in Figure 4. The buck-boost converter utilizes voltage
mode control and the value of R2 plays an integral role
in the dynamics of the feedback loop. In general, a larger
value for R2 will increase stability and reduce the speed of
the transient response. A smaller value of R2 will reduce
stability but increase the transient response speed. A good
starting point is to choose R2 = 1MΩ, then calculate the
required value of R1 to set the desired output voltage ac-
cording to the above formula. If a large output capacitor
is used, the bandwidth of the converter is reduced. In
such cases R2 can be reduced to improve the transient
response. If a large inductor or small output capacitor is
utilized, the loop will be less stable and the phase margin
can be improved by increasing the value of R2.
Buck-Boost Inductor Selection
To achieve high efficiency, a low ESR inductor should be
utilized for the buck-boost converter. The inductor must
haveasaturationratinggreaterthantheworstcaseaverage
inductor current plus half the ripple current. The peak-to-
peakinductorcurrentripplewillbelargerinbuckandboost
mode than in the buck-boost region. The peak-to-peak
inductor current ripple for each mode can be calculated
APPLICATIONS INFORMATION
LTC3521
GND
0.6V
≤ VOUT3 ≤ 5.25V
0.6V
≤ VOUT2 ≤ 5.25V
FB3
R1
3521 F03
R2
FB2
R1
R2
Figure 3. Setting the Buck Output Voltage
LTC3521
GND
1.8V
≤ VOUT1 ≤ 5.25V
FB1
R1
3521 F04
R2
Figure 4. Setting the Buck-Boost Output Voltage
相關(guān)PDF資料
PDF描述
LTC3525DESC6-3.3#PBF 0.45 A SWITCHING REGULATOR, PDSO6
LTC3525LESC6-3TRM 0.45 A SWITCHING REGULATOR, PDSO6
LTC3525LESC6-3 0.45 A SWITCHING REGULATOR, PDSO6
LTC3526BEDC-2 0.5 A SWITCHING REGULATOR, 2400 kHz SWITCHING FREQ-MAX, PDSO6
LTC3526EDC 0.5 A SWITCHING CONTROLLER, 1300 kHz SWITCHING FREQ-MAX, PDSO6
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC3522 制造商:LINER 制造商全稱:Linear Technology 功能描述:Synchronous 400mA Buck-Boost and 200mA Buck Converters
LTC3522EUD 制造商:LINER 制造商全稱:Linear Technology 功能描述:Synchronous 400mA Buck-Boost and 200mA Buck Converters
LTC3522EUD#PBF 功能描述:IC REG BUCK BOOST SYNC ADJ 16QFN 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:- 產(chǎn)品培訓(xùn)模塊:MIC23xxx HyperLight Load™ Regulators 標(biāo)準(zhǔn)包裝:5,000 系列:HyperLight Load® 類型:降壓（降壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:1.8V 輸入電壓:2.7 V ~ 5.5 V PWM 型:混合物 頻率 - 開關(guān):4MHz 電流 - 輸出:2A 同步整流器:是 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:8-VFDFN 裸露焊盤，8-MLF? 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:8-MLF?（2x2） 產(chǎn)品目錄頁(yè)面:1094 (CN2011-ZH PDF) 其它名稱:576-3303-2
LTC3522EUD#TRPBF 功能描述:IC REG BUCK BOOST SYNC ADJ 16QFN 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:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 類型:降壓（降壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:1.2V，1.5V，1.8V，2.5V 輸入電壓:2.7 V ~ 20 V PWM 型:- 頻率 - 開關(guān):- 電流 - 輸出:50mA 同步整流器:是 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:10-TFSOP，10-MSOP（0.118"，3.00mm 寬）裸露焊盤 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:10-MSOP 裸露焊盤
LTC3523 制造商:LINER 制造商全稱:Linear Technology 功能描述:Synchronous 600mA Step-Up and 400mA Step-Down DC/DC Converters
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

*
*
*