- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄30767 > LT3641IUFD#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： | LT3641IUFD#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)： | 3/28頁 |
| 文件大小： | 416K |
| 代理商： | LT3641IUFD#TRPBF |
第1頁第2頁當前第3頁第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
11
3641f
when the VIN2 pin voltage is above 2.3V, and the EN2 pin
is above its threshold. The internal top power MOSFET is
turned on each cycle at the beginning of each oscillator
cycle, and turned off when the current owing through
the top MOSFET reaches a level determined by the voltage
at the VC2 node. An error amplier measures the output
voltage through an external resistor divider tied to the FB2
pin and servos the VC2 node. The reference of the error
amplier is determined by the lower of the internal 600mV
reference and the voltage at the SS2 pin.
While the top MOSFET is off, the bottom MOSFET is
turned on in an oscillator cycle until the inductor current
starts to reverse. If the inductor current is higher than the
valley current limit at the beginning of an oscillator cycle,
the bottom MOSFET will remain on and prevent the top
MOSFET from turning on until the overcurrent situation
clears, limiting inductor current in shorted output fault.
An internal regulator provides power to the control circuitry.
The regulator draws most power from the VIN2 pin and a
small portion of power from the VIN pin when the VIN2 pin
voltage is higher than 3V. If the voltage at VIN2 pin is lower
than 3V, the regulator draws all power from the VIN pin.
The EN/UVLO pin is used to put the LT3641 in shutdown,
reducing the input current to less than 1μA. The accurate
1.26V threshold of the EN/UVLO pin provides a program-
mable VINundervoltagelockoutthroughanexternalresistor
divider tied to the EN/UVLO pin. A 2μA hysteresis current
on the EN/UVLO pin prevents switching noise from shut-
ting down the LT3641.
The LT3641 has an overtemperature protection feature
which disables switching in both channels when the junc-
tion temperature exceeds the overtemperature threshold.
Junction temperature will exceed the maximum operating
junction when overtemperature protection is active.
Internal 2μA current sources charge the SS1 pin and the SS2
pin up to about 2V. Soft-start or output voltage tracking of
the two channels can be independently implemented with
capacitors from the SS1 pin and the SS2 pin to ground. Any
undervoltage condition on the VIN pin triggers an internal
latch that discharges the SS1 pin to below 100mV before
it is released. If the EN2 pin goes below its threshold,
or the VIN2 voltage falls below 2.2V, the SS2 pin will be
discharged to below 100mV before it is released.
To optimize efciency, the LT3641 switches to low ripple
Burst Mode operation in light load situations. Between
switching pulses, control-circuitry current is minimized.
A power good comparator with 40mV of hysteresis trips
when the low voltage channel is enabled and the FB2 pin
is above 550mV. The PGOOD2 pin is an open-drain output
that is pulled low when both the outputs are in regulation.
Power-On Reset and Watchdog Timer
The LT3641 includes one power-on reset timer for each
buck regulator and one common watchdog timer. Power-
on reset and watchdog timers are both adjustable using
external capacitors. Operation can be best understood by
referring to the Timing Diagram.
The RST1, RST2 and WDO pins are all open-drain outputs
with weak internal pull-ups to about 2V. The RST1 and RST2
pins are pulled low when the LT3641 is enabled and VIN is
above 3.6V. Once the FB1 pin rises above 1.165V, the high
voltage channel reset timer is started and RST1 is released
after the reset timeout period. The low voltage channel reset
timer is started once the FB2 pin rises above 550mV, and
releases RST2 after the reset timeout period.
The watchdog circuit monitors a μP’s activity. As soon as
RST2 is released, a delay timer is started. The watchdog
timer is started after the delay timer times out. The LT3641
implements windowed watchdog function for higher sys-
tem reliability. The watchdog timer detects falling edges
on the WDI pin. If the falling edges are grouped too close
together or too far apart, the WDO pin is pulled down and
the reset timer is started. When the reset timer times out,
WDO is released and the watchdog timer is again started
after the delay period.
OPERATION
相關PDF資料 |
PDF描述 |
|---|---|
| LT3641EFE#TRPBF | 3.4 A DUAL SWITCHING CONTROLLER, 2350 kHz SWITCHING FREQ-MAX, PDSO28 |
| LT3641EUFD#TRPBF | 3.4 A DUAL SWITCHING CONTROLLER, 2350 kHz SWITCHING FREQ-MAX, PQCC28 |
| 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 |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| LT3645 | 制造商:LINER 制造商全稱:Linear Technology 功能描述:36V 500mA Step-Down Regulator and 200mA LDO |
| LT3645EMSE#PBF | 功能描述:IC REG DL BUCK/LINEAR 12-MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標準包裝:2,500 系列:- 拓撲:降壓（降壓）同步（3），線性（LDO）（2） 功能:任何功能 輸出數(shù):5 頻率 - 開關:300kHz 電壓/電流 - 輸出 1:控制器 電壓/電流 - 輸出 2:控制器 電壓/電流 - 輸出 3:控制器 帶 LED 驅動器:無 帶監(jiān)控器:無 帶序列發(fā)生器:是 電源電壓:5.6 V ~ 24 V 工作溫度:-40°C ~ 85°C 安裝類型:* 封裝/外殼:* 供應商設備封裝:* 包裝:* |
| LT3645EMSE#TRPBF | 功能描述:IC REG DL BUCK/LINEAR 12-MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標準包裝:2,500 系列:- 拓撲:降壓（降壓）同步（3），線性（LDO）（2） 功能:任何功能 輸出數(shù):5 頻率 - 開關:300kHz 電壓/電流 - 輸出 1:控制器 電壓/電流 - 輸出 2:控制器 電壓/電流 - 輸出 3:控制器 帶 LED 驅動器:無 帶監(jiān)控器:無 帶序列發(fā)生器:是 電源電壓:5.6 V ~ 24 V 工作溫度:-40°C ~ 85°C 安裝類型:* 封裝/外殼:* 供應商設備封裝:* 包裝:* |
| LT3645EMSEPBF | 制造商:Linear Technology 功能描述:36V 0.5A Sw. Regulator 0.2A LDO MSOP12EP |
| LT3645EUD#PBF | 功能描述:IC REG DL BUCK/LINEAR 16-QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標準包裝:2,500 系列:- 拓撲:降壓（降壓）同步（3），線性（LDO）（2） 功能:任何功能 輸出數(shù):5 頻率 - 開關:300kHz 電壓/電流 - 輸出 1:控制器 電壓/電流 - 輸出 2:控制器 電壓/電流 - 輸出 3:控制器 帶 LED 驅動器:無 帶監(jiān)控器:無 帶序列發(fā)生器:是 電源電壓:5.6 V ~ 24 V 工作溫度:-40°C ~ 85°C 安裝類型:* 封裝/外殼:* 供應商設備封裝:* 包裝:* |
發(fā)布緊急采購，3分鐘左右您將得到回復。