- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄67757 > LT3493IDCB#PBF (LINEAR TECHNOLOGY CORP) 2.2 A SWITCHING REGULATOR, 815 kHz SWITCHING FREQ-MAX, PDSO6 PDF資料下載
參數(shù)資料
| 型號(hào)： | LT3493IDCB#PBF |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 2.2 A SWITCHING REGULATOR, 815 kHz SWITCHING FREQ-MAX, PDSO6 |
| 封裝： | 2 X 3 MM, LEAD FREE, PLASTIC, MO-229, DFN-6 |
| 文件頁數(shù)： | 5/20頁 |
| 文件大?。?/td> | 588K |
| 代理商： | LT3493IDCB#PBF |
LT3493
13
3493fb
APPLICATIONS INFORMATION
At light loads, the inductor current becomes discontinu-
ous and the effective duty cycle can be very high. This
reduces the minimum input voltage to approximately
400mV above VOUT. At higher load currents, the inductor
current is continuous and the duty cycle is limited by the
maximum duty cycle of the LT3493, requiring a higher
input voltage to maintain regulation.
Soft-Start
The SHDN pin can be used to soft-start the LT3493, reducing
the maximum input current during start-up. The SHDN pin
is driven through an external RC lter to create a voltage
ramp at this pin. Figure 7 shows the start-up waveforms
with and without the soft-start circuit. By choosing a large
RC time constant, the peak start-up current can be reduced
to the current that is required to regulate the output, with
no overshoot. Choose the value of the resistor so that it
can supply 20μA when the SHDN pin reaches 2.3V.
Shorted and Reversed Input Protection
If the inductor is chosen so that it won’t saturate exces-
sively, an LT3493 buck regulator will tolerate a shorted
output. There is another situation to consider in systems
where the output will be held high when the input to the
LT3493 is absent. This may occur in battery charging ap-
plications or in battery backup systems where a battery
or some other supply is diode OR-ed with the LT3493’s
output. If the VIN pin is allowed to oat and the SHDN pin
is held high (either by a logic signal or because it is tied
to VIN), then the LT3493’s internal circuitry will pull its
quiescent current through its SW pin. This is ne if your
system can tolerate a few mA in this state. If you ground
the SHDN pin, the SW pin current will drop to essentially
zero. However, if the VIN pin is grounded while the output
is held high, then parasitic diodes inside the LT3493 can
pull large currents from the output through the SW pin
and the VIN pin. Figure 8 shows a circuit that will run only
when the input voltage is present and that protects against
a shorted or reversed input.
Hot Plugging Safely
The small size, robustness and low impedance of ceramic
capacitors make them an attractive option for the input
bypass capacitor of LT3493 circuits. However, these capaci-
tors can cause problems if the LT3493 is plugged into a
live supply (see Linear Technology Application Note 88 for
IOUT (mA)
1
5.0
V
IN
(V)
6.5
7.0
7.5
10
100
1000
3493 G15
6.0
5.5
TO START
TO RUN
IOUT (mA)
1
4.3
V
IN
(V)
4.5
4.7
4.9
5.1
10
100
1000
3493 G16
4.1
3.9
3.7
3.5
5.3
5.5
TO START
TO RUN
(6a) Typical Minimum Input Voltage, VOUT = 5V
(6b) Typical Minimum Input Voltage, VOUT = 3.3V
Figure 6
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LT3493EDCB#TRM | 2.2 A SWITCHING REGULATOR, 815 kHz SWITCHING FREQ-MAX, PDSO6 |
| LT3493EDCB#TR | 2.2 A SWITCHING REGULATOR, 815 kHz SWITCHING FREQ-MAX, PDSO6 |
| LT3513EUHF#TRPBF | 3.5 A SWITCHING REGULATOR, 2220 kHz SWITCHING FREQ-MAX, PQCC38 |
| LT3513EUHF#PBF | 3.5 A SWITCHING REGULATOR, 2220 kHz SWITCHING FREQ-MAX, PQCC38 |
| LT3513IUHF#TRPBF | 3.5 A SWITCHING REGULATOR, 2220 kHz SWITCHING FREQ-MAX, PQCC38 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LT3493IDCB-TR | 制造商:LINER 制造商全稱:Linear Technology 功能描述:1.2A, 750kHz Step-Down Switching Regulator in 2mm × 3mm DFN |
| LT3493IDCBTRMPBF | 制造商:Linear Technology 功能描述:DC-DC Converter Step-Down 3.6-36V DFN6EP |
| LT3493IDCB-TRPBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:1.2A, 750kHz Step-Down Switching Regulator in 2mm × 3mm DFN |
| LT3494 | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Micropower Low Noise Boost Converters with Output Disconnect |
| LT3494A | 制造商:LINER 制造商全稱:Linear Technology 功能描述:20mA LED Driver and OLED Driver with Integrated Schottky in 3mm x 2mm DFN |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。