- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄44983 > LT3430IFE-1#TR (LINEAR TECHNOLOGY CORP) 6.5 A SWITCHING REGULATOR, 120 kHz SWITCHING FREQ-MAX, PDSO16 PDF資料下載
參數(shù)資料
| 型號： | LT3430IFE-1#TR |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 6.5 A SWITCHING REGULATOR, 120 kHz SWITCHING FREQ-MAX, PDSO16 |
| 封裝： | 4.40 MM, PLASTIC, TSSOP-16 |
| 文件頁數(shù)： | 4/28頁 |
| 文件大小： | 321K |
| 代理商： | LT3430IFE-1#TR |
第1頁第2頁第3頁當前第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
LT3430/LT3430-1
12
34301fa
Reduced Inductor Value and Discontinuous Mode
If the smallest inductor value is of most importance to a
converter design, in order to reduce inductor size/cost,
discontinuous mode may yield the smallest inductor solu-
tion. The maximum output load current in discontinuous
mode, however, must be calculated and is dened later
in this section.
Discontinuous mode is entered when the output load
current is less than one-half of the inductor ripple current
(ILP-P). In this mode, inductor current falls to zero before
the next switch turn on (see Figure 8). Buck converters
will be in discontinuous mode for output load current
given by:
IOUT
Discontinuous Mode
<
+
()(
–
)
()(
)( )()
VV V
V
Vf L
OUT
F
IN
OUT
F
IN
2
The inductor value in a buck converter is usually chosen
large enough to keep inductor ripple current (ILP-P) low;
this is done to minimize output ripple voltage and maximize
output load current. In the case of large inductor values,
as seen in the equation above, discontinuous mode will
be associated with “l(fā)ight loads.”
When choosing small inductor values, however, discontinu-
ous mode will occur at much higher output load currents.
The limit to the smallest inductor value that can be chosen
is set by the LT3430/LT3430-1 peak switch current (IP) and
the maximum output load current required, given by:
IOUT(MAX)
Discontinuous Mode
=<
ILP-P
2
=
()
+
I
If L V
VV V
V
P
PIN
OUT
F
IN
OUT
F
2
()(
)
()(
–
)
ILP-P
Example: For VIN = 15V, VOUT = 5V, VF = 0.52V, f = 200kHz
and L = 4.7H.
IOUT(MAX)
Discontinuous
Mode
=
+
3
200 10
4 7 10
15
2 5 0 52 1550 52
23
6
(
)( .
)( )
(.
)(
– – .
)
IOUT(MAX)
= 1.21A
Discontinuous Mode
What has been shown here is that if high inductor ripple
current and discontinuous mode operation can be tolerated,
small inductor values can be used. If a higher output load
current is required, the inductor value must be increased.
If IOUT(MAX) no longer meets the discontinuous mode
criteria, use the IOUT(MAX) equation for continuous mode;
the LT3430/LT3430-1 are designed to operate well in both
modes of operation, allowing a large range of inductor
values to be used.
Short-Circuit Considerations
The LT3430/LT3430-1 are current mode controllers. They
use the VC node voltage as an input to a current compara-
tor which turns off the output switch on a cycle-by-cycle
basis as this peak current is reached. The internal clamp on
the VC node, nominally 2V, then acts as an output switch
peak current limit. This action becomes the switch current
limit specication. The maximum available output power
is then determined by the switch current limit.
A potential controllability problem could occur under
short-circuit conditions. If the power supply output is
short circuited, the feedback amplier responds to the
low output voltage by raising the control voltage, VC, to its
peak current limit value. Ideally, the output switch would
be turned on, and then turned off as its current exceeded
the value indicated by VC. However, there is nite response
time involved in both the current comparator and turnoff
of the output switch. These result in a minimum on time
tON(MIN). When combined with the large ratio of VIN to
(VF + I R), the diode forward voltage plus inductor I R
voltage drop, the potential exists for a loss of control.
Expressed mathematically the requirement to maintain
control is:
ft
VI R
V
ON
F
IN
≤
+
APPLICATIONS INFORMATION
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LT3430EFE-1#TR | 6.5 A SWITCHING REGULATOR, 120 kHz SWITCHING FREQ-MAX, PDSO16 |
| LT3430IFE-1 | 6.5 A SWITCHING REGULATOR, 120 kHz SWITCHING FREQ-MAX, PDSO16 |
| LT3430EFE-1 | 6.5 A SWITCHING REGULATOR, 120 kHz SWITCHING FREQ-MAX, PDSO16 |
| LT3467AIDDB#PBF | 2.5 A SWITCHING REGULATOR, 2700 kHz SWITCHING FREQ-MAX, PDSO8 |
| LT3467AIDDB | 2.5 A SWITCHING REGULATOR, 2700 kHz SWITCHING FREQ-MAX, PDSO8 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LT3430IFEPBF | 制造商:Linear Technology 功能描述:Sw. Regulator 3A 200kHz 60V TSSOP16EP |
| LT3431 | 制造商:LINER 制造商全稱:Linear Technology 功能描述:High Voltage, 3A,500kHz Step-Down Switching Regulator |
| LT3431EFE | 功能描述:IC REG BUCK ADJ 3A 16TSSOP RoHS:否 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 標準包裝: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 |
| LT3431EFE#PBF | 功能描述:IC REG BUCK ADJ 3A 16TSSOP 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:- 標準包裝:250 系列:- 類型:降壓（降壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:1.2V 輸入電壓:2.05 V ~ 6 V PWM 型:電壓模式 頻率 - 開關(guān):2MHz 電流 - 輸出:500mA 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:6-UFDFN 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:6-SON（1.45x1） 產(chǎn)品目錄頁面:1032 (CN2011-ZH PDF) 其它名稱:296-25628-2 |
| LT3431EFE#TR | 功能描述:IC REG BUCK ADJ 3A 16TSSOP RoHS:否 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 標準包裝: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 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。