參數(shù)資料
型號(hào)： LTC3872ETS8
廠商： LINEAR TECHNOLOGY CORP
元件分類： 穩(wěn)壓器
英文描述： SWITCHING CONTROLLER, 650 kHz SWITCHING FREQ-MAX, PDSO8
封裝： 1 MM HEIGHT, PLASTIC, MO-193, TSOT-23, 8 PIN
文件頁(yè)數(shù)： 18/20頁(yè)
文件大?。?/td> 261K
代理商： LTC3872ETS8
LTC3872
7
3872fa
APPLICATIO S I FOR ATIO
WU
U
Output Voltage Programming
The output voltage is set by a resistor divider according
to the following formula:
VV
R
O =+
12
1
2
1
.
The external resistor divider is connected to the output
as shown in the Typical Application on the front page,
allowing remote voltage sensing.
Application Circuits
A basic LTC3872 application circuit is shown on the front
page of this datasheet. External component selection is
driven by the characteristics of the load and the input
supply.
Duty Cycle Considerations
For a boost converter operating in a continuous conduction
mode (CCM), the duty cycle of the main switch is:
D
VV
V
VV
OD
IN
OD
=
+
–
where VD is the forward voltage of the boost diode. For
converters where the input voltage is close to the output
voltage, the duty cycle is low and for converters that develop
a high output voltage from a low voltage input supply, the
duty cycle is high. The LTC3872 has a built-in circuit that
allows the extension of the maximum duty cycle while
keeping the minimum switch off time unchanged. This
is accomplished by reducing the clock frequency when
the duty cycle is close to 80%. This function allows the
user to obtain high output voltages from low input supply
voltages. The shift of frequency with duty cycle is shown
in the Typical Performance Characteristics section.
The Peak and Average Input Currents
The control circuit in the LTC3872 is measuring the input
current (either by using the RDS(ON) of the power MOSFET
or by using a sense resistor in the MOSFET source), so
the output current needs to be reected back to the input
in order to dimension the power MOSFET properly. Based
on the fact that, ideally, the output power is equal to the
input power, the maximum average input current is:
I
D
The peak input current is
I
D
IN MAX
OMAX
MAX
IN PEAK
OMAX
MAX
()
–
:
–
=
=+
1
21
χ
Ripple Current IL and the χ Factor
The constant χ in the equation above represents the
percentage peak-to-peak ripple current in the inductor,
relative to its maximum value. For example, if 30% ripple
current is chosen, then χ = 0.30, and the peak current is
15% greater than the average.
For a current mode boost regulator operating in CCM,
slope compensation must be added for duty cycles above
50% in order to avoid subharmonic oscillation. For the
LTC3872, this ramp compensation is internal. Having an
internally xed ramp compensation waveform, however,
does place some constraints on the value of the inductor
and the operating frequency. If too large an inductor is
used, the resulting current ramp (IL) will be small relative
to the internal ramp compensation (at duty cycles above
50%), and the converter operation will approach voltage
mode (ramp compensation reduces the gain of the current
loop). If too small an inductor is used, but the converter
is still operating in CCM (continuous conduction mode),
the internal ramp compensation may be inadequate to
prevent subharmonic oscillation. To ensure good current
相關(guān)PDF資料
PDF描述
LTC3872EDDB#TRM SWITCHING CONTROLLER, 650 kHz SWITCHING FREQ-MAX, PDSO8
LTC3872ITS8#PBF SWITCHING CONTROLLER, 650 kHz SWITCHING FREQ-MAX, PDSO8
LTC3872ITS8#TRPBF SWITCHING CONTROLLER, 650 kHz SWITCHING FREQ-MAX, PDSO8
LTC3872HTS8#TRPBF SWITCHING CONTROLLER, 650 kHz SWITCHING FREQ-MAX, PDSO8
LTC3872HTS8#PBF SWITCHING CONTROLLER, 650 kHz SWITCHING FREQ-MAX, PDSO8
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC3872ETS8#PBF 制造商:Linear Technology 功能描述:DC DC Cntrlr Single-OUT Step Up 2.75V to 9.8V Input 8-Pin TSOT-23 制造商:Linear Technology 功能描述:BOOST 9.8VIN 550KHZ 60V 8TSOT23 制造商:Linear Technology 功能描述:BOOST, 9.8VIN, 550KHZ, 60V, 8TSOT23 制造商:Linear Technology 功能描述:DC-DC CONTROLLER, BOOST, 550KHZ, TSOT-23-8; Primary Input Voltage:9.8V; No. of Outputs:1; Output Current:10A; No. of Pins:8; Operating Temperature Min:-40C; Operating Temperature Max:85C; Package / Case:8-TSOT-23 ;RoHS Compliant: Yes 制造商:Linear Technology 功能描述:DC-DC CONTROLLER, BOOST, 550KHZ, TSOT-23-8; Primary Input Voltage:9.8V; No. of Outputs:1; No. of Pins:8; Operating Temperature Min:-40C; Operating Temperature Max:85C; Package / Case:8-TSOT-23 ;RoHS Compliant: Yes
LTC3872ETS8#TRMPBF 功能描述:IC REG CTRLR BST PWM CM TSOT23-8 RoHS:是 類別: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 包裝:Digi-Reel® 產(chǎn)品目錄頁(yè)面:1303 (CN2011-ZH PDF) 其它名稱:LM3754SQDKR
LTC3872ETS8#TRPBF 功能描述:IC REG CTRLR BST PWM CM TSOT23-8 RoHS:是 類別: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 包裝:帶卷 (TR)
LTC3872HDDB#TRMPBF 功能描述:IC REG CTRLR BST PWM CM 8-DFN RoHS:是 類別: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 包裝:帶卷 (TR)
LTC3872HDDB#TRPBF 功能描述:IC REG CTRLR BST PWM CM 8-DFN RoHS:是 類別: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 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

*
*
*