參數(shù)資料
型號(hào)： LT3845AIFE#TRPBF
廠商： LINEAR TECHNOLOGY CORP
元件分類(lèi)： 穩(wěn)壓器
英文描述： SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16
封裝： 4.40 MM, LEAD FREE, PLASTIC, TSSOP-16
文件頁(yè)數(shù)： 10/26頁(yè)
文件大小： 284K
代理商： LT3845AIFE#TRPBF
LT3845A
18
3845afa
Supply UVLO and Shutdown
The SHDN pin has a precision voltage threshold with
hysteresis which can be used as an undervoltage lockout
threshold (UVLO) for the power supply. Undervoltage
lockout keeps the LT3845A in shutdown until the supply
input voltage is above a certain voltage programmed by
theuser.Thehysteresisvoltagepreventsnoisefromfalsely
tripping UVLO.
Resistors are chosen by first selecting RB. Then
RA =RB
VSUPPLY(ON)
1.35V
– 1
VSUPPLY(ON) is the input voltage at which the undervoltage
lockout is disabled and the supply turns on.
Example: Select RB = 49.9k, VSUPPLY(ON) = 14.5V (based
on a 15V minimum input voltage)
RA =49.9k
14.5V
1.35V
– 1
= 486.1k (499k resistor is selected)
If low supply current in standby mode is required, select
a higher value of RB.
The supply turn off voltage is 9% below turn on. In the
example the VSUPPLY(OFF) would be 13.2V.
If additional hysteresis is desired for the enable function,
an external positive feedback resistor can be used from
the LT3845A regulator output.
The shutdown function can be disabled by connecting the
SHDN pin to the VIN through a large value pull-up resistor.
Thispincontainsalowimpedanceclampat6V,sotheSHDN
pin will sink current from the pull-up resistor(RPU):
I
SHDN =
VIN –6V
RPU
Because this arrangement will clamp the SHDN pin to the
6V,itwillviolatethe5Vabsolutemaximumvoltageratingof
the pin. This is permitted, however, as long as the absolute
maximum input current rating of 1mA is not exceeded.
Input SHDN pin currents of <100A are recommended: a
1MΩ or greater pull-up resistor is typically used for this
configuration.
Soft-Start
The desired soft-start time (tSS) is programmed via the
CSS capacitor as follows:
CSS =
2A tSS
1.231V
Theamountoftimeinwhichthepowersupplycanwithstand
a VIN, VCC or VSHDN UVLO fault condition (tFAULT) before
theCSSpinvoltageentersitsactiveregionisapproximated
by the following formula:
tFAULT =
CSS 0.65V
50A
APPLICATIONS INFORMATION
L1
VFB PIN
R2
R1
VOUT
COUT
3845A F03
SHDN PIN
RA
RB
VSUPPLY
3845A F04
Figure 3. Output Voltage Feedback Divider
Figure 4. Undervoltage Feedback Divider
相關(guān)PDF資料
PDF描述
LT3845AMPFE#PBF SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16
LT3845EFE#TR SWITCHING CONTROLLER, 600 kHz SWITCHING FREQ-MAX, PDSO16
LT3956IUHE#TRPBF SWITCHING REGULATOR, PQCC36
LT3957EUHE#TRPBF SWITCHING REGULATOR, PQCC36
LT3957IUHE#PBF SWITCHING REGULATOR, PQCC36
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LT3845AMPFE#PBF 功能描述:IC REG CTRLR BUCK PWM CM 16TSSOP RoHS:是 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤(pán) 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱(chēng):LM1771SSDX
LT3845AMPFE#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 16TSSOP RoHS:是 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤(pán) 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱(chēng):LM1771SSDX
LT3845EFE 制造商:LINER 制造商全稱(chēng):Linear Technology 功能描述:High Voltage Synchronous Current Mode Step-Down Controller with Adjustable Operating Frequency
LT3845EFE#PBF 功能描述:IC REG CTRLR BUCK PWM CM 16TSSOP RoHS:是 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 特色產(chǎn)品:LM3753/54 Scalable 2-Phase Synchronous Buck Controllers 標(biāo)準(zhǔn)包裝:1 系列:PowerWise® PWM 型:電壓模式 輸出數(shù):1 頻率 - 最大:1MHz 占空比:81% 電源電壓:4.5 V ~ 18 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-5°C ~ 125°C 封裝/外殼:32-WFQFN 裸露焊盤(pán) 包裝:Digi-Reel® 產(chǎn)品目錄頁(yè)面:1303 (CN2011-ZH PDF) 其它名稱(chēng):LM3754SQDKR
LT3845EFE#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 16TSSOP RoHS:是 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- PWM 型:電流模式 輸出數(shù):1 頻率 - 最大:500kHz 占空比:96% 電源電壓:4 V ~ 36 V 降壓:無(wú) 升壓:是 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 125°C 封裝/外殼:24-WQFN 裸露焊盤(pán) 包裝:帶卷 (TR)
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(xiě)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

*
*
*