- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄44994 > LTC3835IGN-1#TR (LINEAR TECHNOLOGY CORP) 3 A SWITCHING CONTROLLER, 580 kHz SWITCHING FREQ-MAX, PDSO16 PDF資料下載
參數(shù)資料
| 型號： | LTC3835IGN-1#TR |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 3 A SWITCHING CONTROLLER, 580 kHz SWITCHING FREQ-MAX, PDSO16 |
| 封裝： | 0.150 INCH, PLASTIC, SSOP-16 |
| 文件頁數(shù)： | 8/28頁 |
| 文件大小： | 303K |
| 代理商： | LTC3835IGN-1#TR |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁當(dāng)前第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
LTC3835-1
16
38351fc
APPLICATIONS INFORMATION
High input voltage applications in which large MOSFETs
are being driven at high frequencies may cause the
maximum junction temperature rating for the LTC3835-1
to be exceeded. The INTVCC current, which is dominated
by the gate charge current, is supplied by the 5.25V VIN
LDO. Power dissipation for the IC in this case is equal
to VIN IINTVCC. The gate charge current is dependent
on operating frequency as discussed in the Efciency
Considerations section. The junction temperature can be
estimated by using the equations given in Note 2 of the
Electrical Characteristics. For example, the LTC3835-1
INTVCC current is limited to less than 25mA from a 24V
supply when in the GN package:
TJ = 70°C + (25mA)(24V)(90°C/W) = 125°C
To prevent the maximum junction temperature from being
exceeded, the input supply current must be checked while
operating in continuous conduction mode (PLLIN/MODE
= INTVCC) at maximum VIN.
Topside MOSFET Driver Supply (CB, DB)
External bootstrap capacitors CB connected to the BOOST
pins supply the gate drive voltages for the topside MOSFET.
Capacitor CB in the Functional Diagram is charged though
external diode DB from INTVCC when the SW pin is low. When
oneofthetopsideMOSFETistobeturnedon,thedriverplaces
the CB voltageacrossthegate-sourceofthedesiredMOSFET.
This enhances the MOSFET and turns on the topside switch.
The switch node voltage, SW, rises to VIN and the BOOST pin
follows. With the topside MOSFET on, the boost voltage is
above the input supply: VBOOST = VIN + VINTVCC. The value
of the boost capacitor CB needs to be 100 times that of the
totalinputcapacitanceofthetopsideMOSFET(s).Thereverse
breakdown of the external Schottky diode must be greater
than VIN(MAX). When adjusting the gate drive level, the nal
arbiter is the total input current for the regulator. If a change
is made and the input current decreases, then the efciency
has improved. If there is no change in input current, then
there is no change in efciency.
Fault Conditions: Current Limit and Current Foldback
The LTC3835-1 includes current foldback to help limit load
current when the output is shorted to ground. If the output
falls below 70% of its nominal output level, then the maxi-
mum sense voltage is progressively lowered from 100mV
to 30mV. Under short-circuit conditions with very low duty
cycles, the LTC3835-1 will begin cycle skipping in order to
limit the short-circuit current. In this situation the bottom
MOSFET will be dissipating most of the power but less than
in normal operation. The short-circuit ripple current is deter-
mined by the minimum on-time tON(MIN) of the LTC3835-1
(≈180ns), the input voltage and inductor value:
ΔIL(SC) = tON(MIN) (VIN/L)
The resulting short-circuit current is:
I
mV
R
I
SC
SENSE
LSC
=
10
1
2
–
()
Δ
Fault Conditions: Overvoltage Protection (Crowbar)
The overvoltage crowbar is designed to blow a system input
fusewhentheoutputvoltageoftheregulatorrisesmuchhigher
thannominallevels.Thecrowbarcauseshugecurrentstoow,
that blow the fuse to protect against a shorted top MOSFET
if the short occurs while the controller is operating.
A comparator monitors the output for overvoltage condi-
tions.Thecomparator(OV)detectsovervoltagefaultsgreater
than 10% above the nominal output voltage. When this
condition is sensed, the top MOSFET is turned off and the
bottom MOSFET is turned on until the overvoltage condition
is cleared. The bottom MOSFET remains on continuously
for as long as the OV condition persists; if VOUT returns to
a safe level, normal operation automatically resumes. A
shorted top MOSFET will result in a high current condition
which will open the system fuse. The switching regulator
will regulate properly with a leaky top MOSFET by altering
the duty cycle to accommodate the leakage.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LTC3835EDHC-1#TRPBF | 3 A SWITCHING CONTROLLER, 580 kHz SWITCHING FREQ-MAX, PDSO16 |
| LTC3835IGN-1 | 3 A SWITCHING CONTROLLER, 580 kHz SWITCHING FREQ-MAX, PDSO16 |
| LTC3835IUFD | 3 A SWITCHING CONTROLLER, 580 kHz SWITCHING FREQ-MAX, PQCC20 |
| LTC3850EUF | 0.1 A DUAL SWITCHING CONTROLLER, 860 kHz SWITCHING FREQ-MAX, PQCC28 |
| LTC3850EUF#TR | 0.1 A DUAL SWITCHING CONTROLLER, 860 kHz SWITCHING FREQ-MAX, PQCC28 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LTC3835IUFD#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 20-QFN 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 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-5°C ~ 125°C 封裝/外殼:32-WFQFN 裸露焊盤 包裝:Digi-Reel® 產(chǎn)品目錄頁面:1303 (CN2011-ZH PDF) 其它名稱:LM3754SQDKR |
| LTC3835IUFD#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 20-QFN 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: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 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX |
| LTC3836EGN#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 28-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 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 升壓:是 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:24-WQFN 裸露焊盤 包裝:帶卷 (TR) |
| LTC3836EGN#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 28-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 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 升壓:是 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-40°C ~ 125°C 封裝/外殼:24-WQFN 裸露焊盤 包裝:帶卷 (TR) |
| LTC3836EUFD#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 28-QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 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 升壓:是 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 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，3分鐘左右您將得到回復(fù)。