- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄44988 > LTC1871IMS#TRPBF-1 (LINEAR TECHNOLOGY CORP) SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO10 PDF資料下載
參數(shù)資料
| 型號： | LTC1871IMS#TRPBF-1 |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO10 |
| 封裝： | LEAD FREE, PLASTIC, MSOP-10 |
| 文件頁數(shù)： | 2/36頁 |
| 文件大?。?/td> | 354K |
| 代理商： | LTC1871IMS#TRPBF-1 |
第1頁當(dāng)前第2頁第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頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁
10
LTC1871-1
18711fa
APPLICATIO S I FOR ATIO
WU
UU
When the oscillator’s internal logic circuitry detects a
synchronizing signal on the MODE/SYNC pin, the internal
oscillator ramp is terminated early and the slope compen-
sation is increased by approximately 30%. As a result, in
applications requiring synchronization, it is recommended
that the nominal operating frequency of the IC be pro-
grammed to be about 75% of the external clock frequency.
Attempting to synchronize to too high an external fre-
quency (above 1.3fO) can result in inadequate slope com-
pensation and possible subharmonic oscillation (or jitter).
The external clock signal must exceed 2V for at least 25ns,
and should have a maximum duty cycle of 80%, as shown
in Figure 5. The MOSFET turn on will synchronize to the
rising edge of the external clock signal.
pin is used to charge and discharge an internal oscillator
capacitor. A graph for selecting the value of RT for a given
operating frequency is shown in Figure 6.
Figure 6. Timing Resistor (RT) Value
Figure 5. MODE/SYNC Clock Input and Switching
Waveforms for Synchronized Operation
1871 F05
2V TO 7V
MODE/
SYNC
GATE
IL
tMIN = 25ns
0.8T
D = 40%
T
T = 1/fO
FREQUENCY (kHz)
100
R
T(k
Ω
)
300
1000
1871 F06
10
100
200
1000
900
800
700
600
500
400
0
Programming the Operating Frequency
The choice of operating frequency and inductor value is a
tradeoff between efficiency and component size. Low
frequency operation improves efficiency by reducing
MOSFET and diode switching losses. However, lower
frequency operation requires more inductance for a given
amount of load current.
The LTC1871-1 uses a constant frequency architecture
that can be programmed over a 50kHz to 1000kHz range
with a single external resistor from the FREQ pin to
ground, as shown in Figure 1. The nominal voltage on the
FREQ pin is 0.6V, and the current that flows into the FREQ
INTVCC Regulator Bypassing and Operation
An internal, P-channel low dropout voltage regulator pro-
duces the 5.2V supply which powers the gate driver and
logic circuitry within the LTC1871-1, as shown in Figure 7.
The INTVCC regulator can supply up to 50mA and must be
bypassed to ground immediately adjacent to the IC pins
with a minimum of 4.7
μF tantalum or ceramic capacitor.
Good bypassing is necessary to supply the high transient
currents required by the MOSFET gate driver.
For input voltages that don’t exceed 7V (the absolute
maximum rating for this pin), the internal low dropout
regulator in the LTC1871-1 is redundant and the INTVCC
pin can be shorted directly to the VIN pin. With the INTVCC
pin shorted to VIN, however, the divider that programs the
regulated INTVCC voltage will draw 10μA of current from
the input supply, even in shutdown mode. For applications
that require the lowest shutdown mode input supply
current, do not connect the INTVCC pin to VIN. Regardless
of whether the INTVCC pin is shorted to VIN or not, it is
always necessary to have the driver circuitry bypassed
with a 4.7
μF tantalum or low ESR ceramic capacitor to
ground immediately adjacent to the INTVCC and GND
pins.
In an actual application, most of the IC supply current is
used to drive the gate capacitance of the power MOSFET.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LTC1871HMS#TR | 0.05 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO10 |
| LTC1871HMS | 0.05 A SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO10 |
| LTC1877IMS8#TRPBF | 1.5 A SWITCHING REGULATOR, 605 kHz SWITCHING FREQ-MAX, PDSO8 |
| LTC1929IG-PG | 3 A DUAL SWITCHING CONTROLLER, 310 kHz SWITCHING FREQ-MAX, PDSO28 |
| LTC203MJ/883B | QUAD 1-CHANNEL, SGL POLE SGL THROW SWITCH, CDIP16 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LTC1872BES6 | 制造商:Linear Technology 功能描述:DC DC Cntrlr Single-OUT Step Up 2.5V to 9.8V Input 6-Pin TSOT-23 |
| LTC1872BES6#PBF | 制造商:Linear Technology 功能描述:DC-DC CONTROLLER BOOST 550KH 制造商:Linear Technology 功能描述:DC-DC CONTROLLER, BOOST, 550KHZ, SOT-23-6; Primary Input Voltage:9.8V; No. of Outputs:1; No. of Pins:6; Operating Temperature Min:-40C; Operating Temperature Max:85C; Package / Case:6-SOT-23 ;RoHS Compliant: Yes |
| LTC1872BES6#TR | 功能描述:IC REG CTRLR BST PWM CM SOT23-6 RoHS:否 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 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) |
| LTC1872BES6#TRM | 功能描述:IC REG CTRLR BST PWM CM SOT23-6 RoHS:否 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:4,000 系列:- PWM 型:電壓模式 輸出數(shù):1 頻率 - 最大:1.5MHz 占空比:66.7% 電源電壓:4.75 V ~ 5.25 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 ~ 85°C 封裝/外殼:40-VFQFN 裸露焊盤 包裝:帶卷 (TR) |
| LTC1872BES6#TRMPBF | 功能描述:IC REG CTRLR BST PWM CM SOT23-6 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 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。