- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄30770 > LTC3546EUFD#PBF (LINEAR TECHNOLOGY CORP) DUAL SWITCHING CONTROLLER, 4000 kHz SWITCHING FREQ-MAX, PQCC28 PDF資料下載
參數(shù)資料
| 型號： | LTC3546EUFD#PBF |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | DUAL SWITCHING CONTROLLER, 4000 kHz SWITCHING FREQ-MAX, PQCC28 |
| 封裝： | 4 X 5 MM, LEAD FREE, PLASTIC, MO-220, QFN-28 |
| 文件頁數(shù)： | 6/28頁 |
| 文件大?。?/td> | 356K |
| 代理商： | LTC3546EUFD#PBF |
第1頁第2頁第3頁第4頁第5頁當(dāng)前第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
LTC3546
14
3546fb
APPLICATIONS INFORMATION
A general LTC3546 application circuit is shown in Figure 7.
External component selection is driven by the load require-
ment, and begins with the selection of the inductors L1,
and L2. Once L1 and L2 are chosen, CIN, COUT1, and COUT2
can be selected.
Operating Frequency
Selection of the operating frequency is a trade-off between
efciency and component size. High frequency operation
allows the use of smaller inductor and capacitor values.
Operation at lower frequencies improves efciency by
reducing internal gate charge losses but requires larger
inductance values and/or capacitance to maintain low
output ripple voltage.
The operating frequency, fO, of the LTC3546 is determined
by pulling the FREQ pin to VIN, for 2.25MHz operation, by
connecting an external resistor from FREQ to ground, or
by driving an external clock signal into SYNC/MODE.
When using an external resistor to set the oscillator fre-
quency use the following equation:
R
T =
2.5110
11
f
O
Ω
() –20kΩ
for 0.75MHz ≤ fO ≤ 4MHz. Or use Figure 1 to select the
value for RT.
The maximum operating frequency is also constrained
by the minimum on-time (typically 70ns) and duty cycle,
especially when forced continuous mode is selected.
Assuming a worst-case minimum on-time of 150ns, this
can be calculated as:
fO(MAX) 6.67
VOUT
VIN(MAX)
MHz
()
The minimum frequency is limited by leakage and noise
coupling due to the large resistance of RT.
Inductor Selection
Although the inductor does not inuence the operat-
ing frequency, the inductor value has a direct effect on
ripple current. The inductor ripple current ΔIL decreases
with higher inductance and increases with higher VIN or
VOUT.
IL =
VOUT
fO L
1
VOUT
VIN
Accepting larger values of ΔIL allows the use of low induc-
tances, but results in higher output voltage ripple, greater
core losses, and lower output current capability.
A reasonable starting point for setting ripple current is ΔIL
= 0.35ILOAD(MAX),whereILOAD(MAX)isthemaximumoutput
current. The largest ripple ΔIL occurs at the maximum
input voltage. To guarantee that the ripple current stays
below a specied maximum, the inductor value should be
chosen according to the following equation:
L
VOUT
fO IL
1
VOUT
VIN(MAX)
Figure 1. Frequency vs RT
FREQUENCY (MHz)
0
R
T(kΩ)
500
50
450
350
250
150
400
300
200
100
0
2.5
1.5
3.5
3546 F01
4.5
2.0
4.0
1.0
3.0
0.5
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LTC3546IUFD | DUAL SWITCHING CONTROLLER, 4000 kHz SWITCHING FREQ-MAX, PQCC28 |
| LTC3546EUFD | DUAL SWITCHING CONTROLLER, 4000 kHz SWITCHING FREQ-MAX, PQCC28 |
| LTC3546IUFD#TR | DUAL SWITCHING CONTROLLER, 4000 kHz SWITCHING FREQ-MAX, PQCC28 |
| LTC3546EFE | DUAL SWITCHING CONTROLLER, 4000 kHz SWITCHING FREQ-MAX, PDSO28 |
| LTC3546IFE#TRPBF | DUAL SWITCHING CONTROLLER, 4000 kHz SWITCHING FREQ-MAX, PDSO28 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LTC3546EUFDTRPBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Dual Synchronous, 3A/1A or 2A/2A Confi gurable Step-Down DC/DC Regulator |
| LTC3546IFE#PBF | 功能描述:IC REG BUCK SYNC ADJ DL 28TSSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 設(shè)計資源:Design Support Tool 標(biāo)準(zhǔn)包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開關(guān):- 電流 - 輸出:100mA 同步整流器:是 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-5 細型，TSOT-23-5 包裝:剪切帶 (CT) 供應(yīng)商設(shè)備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT |
| LTC3546IFE#TRPBF | 功能描述:IC REG BUCK SYNC ADJ DL 28TSSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 設(shè)計資源:Design Support Tool 標(biāo)準(zhǔn)包裝:1 系列:- 類型:升壓（升壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3V 輸入電壓:0.75 V ~ 2 V PWM 型:- 頻率 - 開關(guān):- 電流 - 輸出:100mA 同步整流器:是 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-5 細型，TSOT-23-5 包裝:剪切帶 (CT) 供應(yīng)商設(shè)備封裝:TSOT-23-5 其它名稱:AS1323-BTTT-30CT |
| LTC3546IFEPBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Dual Synchronous, 3A/1A or 2A/2A Confi gurable Step-Down DC/DC Regulator |
| LTC3546IFETRPBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Dual Synchronous, 3A/1A or 2A/2A Confi gurable Step-Down DC/DC Regulator |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。