- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄39399 > LT3500HMSE#TRPBF (LINEAR TECHNOLOGY CORP) 3.5 A SWITCHING REGULATOR, 2800 kHz SWITCHING FREQ-MAX, PDSO16 PDF資料下載
參數(shù)資料
| 型號： | LT3500HMSE#TRPBF |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 3.5 A SWITCHING REGULATOR, 2800 kHz SWITCHING FREQ-MAX, PDSO16 |
| 封裝： | LEAD FREE, PLASTIC, MSOP-16 |
| 文件頁數(shù)： | 6/28頁 |
| 文件大?。?/td> | 318K |
| 代理商： | LT3500HMSE#TRPBF |
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
LT3500
14
3500fc
APPLICATIONS INFORMATION
To maintain output regulation, this peak current must be
less than the LT3500’s switch current limit, ILIM. ILIM is
guaranteed to be greater than 2.3A over the entire duty
cycle range. The maximum output current is a function
of the chosen inductor value:
I
OUT1(MAX) = ILIM
ΔI
L
2
=2.3 –
ΔI
L
2
If the inductor value is chosen so that the ripple current
is small, then the available output current will be near the
switch current limit.
One approach to choosing the inductor is to start with the
simple rule given above, look at the available inductors
and choose one to meet cost or space goals. Then use
these equations to check that the LT3500 will be able to
deliver the required output current. Note again that these
equations assume that the inductor current is continuous.
Discontinuous operation occurs when IOUT1 is less than
IL/2 as calculated above.
Figure 4 illustrates the inductance value needed for a 3.3V
output with a maximum load capability of 2A. Referring
to Figure 4, an inductor value between 3.3μH and 4.7μH
will be sufcient for a 15V input voltage and a switch
frequency of 750kHz. There are several graphs in the
Typical Performance Characteristics section of this data
sheet that show inductor selection as a function of input
voltage and switch frequency for several popular output
voltages and output ripple currents. Also, low inductance
may result in discontinuous mode operation, which is
okay, but further reduces maximum load current. For
details of maximum output current and discontinuous
mode operation, see Linear Technology Application Note
44. Finally, for duty cycles greater than 50% (VOUT1/VIN
> 0.5), there is a minimum inductance required to avoid
subharmonic oscillations. See Application Note 19 for
more information.
Input Capacitor Selection
Bypass the input of the LT3500 circuit with a 4.7μF or
higher ceramic capacitor of X7R or X5R type. A lower
value or a less expensive Y5V type can be used if there
is additional bypassing provided by bulk electrolytic or
tantalum capacitors. The following paragraphs describe
the input capacitor considerations in more detail.
Step-down regulators draw current from the input sup-
ply in pulses with very fast rise and fall times. The input
capacitor is required to reduce the resulting voltage
ripple at the LT3500 and to force this very high frequency
switching current into a tight local loop, minimizing EMI.
The input capacitor must have low impedance at the
switching frequency to do this effectively, and it must
have an adequate ripple current rating.
A conservative value is the RMS input current is given
by:
I
CIN(RMS) =
I
OUT1 VOUT1 VIN VOUT1
()
0.5
V
IN
<
I
OUT1
2
and is largest when VIN = 2VOUT1 (50% duty cycle).
Figure 4. Inductor Values for 2A Maximum Load Current
(VOUT1 = 3.3V, IRIPPLE = 1A)
INPUT VOLTAGE (V)
5
250
FREQUENCY
(kHz)
500
1000
1250
1500
25
2500
3500 F04
750
15
10
30
35
20
40
1750
2000
2250
L = 6.8μH
L = 4.7μH
L = 3.3μH
L = 2.2μH
L = 1.5μH
L = 1μH
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LT3500IMSE#TRPBF | 3.5 A SWITCHING REGULATOR, 2800 kHz SWITCHING FREQ-MAX, PDSO16 |
| LT3757MPMSE#TRPBF | SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO10 |
| LT3757HMSE#TRPBF | SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO10 |
| LT574AKNW | 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, PARALLEL ACCESS, PDIP28 |
| LT574ALNW | 1-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, PARALLEL ACCESS, PDIP28 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LT3500IDD#PBF | 功能描述:IC REG DL BUCK/LINEAR 12-DFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 拓?fù)?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(guān):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(qū)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(yīng)商設(shè)備封裝:* 包裝:* |
| LT3500IDD#TRPBF | 功能描述:IC REG DL BUCK/LINEAR 12-DFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 拓?fù)?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(guān):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(qū)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(yīng)商設(shè)備封裝:* 包裝:* |
| LT3500IDD-PBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Monolithic 2A Step-Down Regulator Plus Linear Regulator/Controller |
| LT3500IDD-TRPBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Monolithic 2A Step-Down Regulator Plus Linear Regulator/Controller |
| LT3500IMSE#PBF | 功能描述:IC REG DL BUCK/LINEAR 16-MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 + 切換式 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 拓?fù)?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(guān):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(qū)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(yīng)商設(shè)備封裝:* 包裝:* |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。