- 您現(xiàn)在的位置：買(mǎi)賣(mài)IC網(wǎng) > PDF目錄44984 > LT3493EDCB-3#TR (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)： | LT3493EDCB-3#TR |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類(lèi)： | 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, PLASTIC, MO-229, DFN-6 |
| 文件頁(yè)數(shù)： | 2/20頁(yè) |
| 文件大?。?/td> | 401K |
| 代理商： | LT3493EDCB-3#TR |
第1頁(yè)當(dāng)前第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)
10
LT3493-3
3493-3f
larger value provides a higher maximum load current and
reduces output voltage ripple at the expense of slower
transient response. If your load is lower than 1.2A, then
you can decrease the value of the inductor and operate
with higher ripple current. This allows you to use a
physically smaller inductor, or one with a lower DCR
resulting in higher efficiency. There are several graphs in
the Typical Performance Characteristics section of this
data sheet that show the maximum load current as a
function of input voltage and inductor value for several
popular output voltages. Low inductance may result in
discontinuous mode operation, which is okay, but further
reduces maximum load current. For details of the maxi-
mum output current and discontinuous mode operation,
see Linear Technology Application Note 44.
Catch Diode
Depending on load current, a 1A to 2A Schottky diode is
recommended for the catch diode, D1. The diode must
have a reverse voltage rating equal to or greater than the
maximum input voltage. The ON Semiconductor MBRM140
is a good choice; it is rated for 1A continuous forward
current and a maximum reverse voltage of 40V.
Input Capacitor
Bypass the input of the LT3493-3 circuit with a 1
F or
higher value ceramic capacitor of X7R or X5R type. Y5V
types have poor performance over temperature and ap-
plied voltage and should not be used. A 1
F ceramic is
adequate to bypass the LT3493-3 and will easily handle
the ripple current. However, if the input power source has
high impedance, or there is significant inductance due to
long wires or cables, additional bulk capacitance may be
APPLICATIO S I FOR ATIO
WU
U
Table 1. Inductor Vendors
Vendor
URL
Part Series
Inductance Range (
H)
Size (mm)
Sumida
www.sumida.com
CDRH4D28
1.2 to 4.7
4.5
× 4.5
CDRH5D28
2.5 to 10
5.5
× 5.5
CDRH8D28
2.5 to 33
8.3
× 8.3
Toko
www.toko.com
A916CY
2 to 12
6.3
× 6.2
D585LC
1.1 to 39
8.1
× 8.0
Würth Elektronik
www.we-online.com
WE-TPC(M)
1 to 10
4.8
× 4.8
WE-PD2(M)
2.2 to 22
5.2
× 5.8
WE-PD(S)
1 to 27
7.3
× 7.3
necessary. This can be provided with a low performance
electrolytic capacitor.
Step-down regulators draw current from the input supply
in pulses with very fast rise and fall times. The input
capacitor is required to reduce the resulting voltage ripple
at the LT3493-3 and to force this very high frequency
switching current into a tight local loop, minimizing EMI.
A 1
F capacitor is capable of this task, but only if it is
placed close to the LT3493-3 and the catch diode; see the
PCB Layout section. A second precaution regarding the
ceramic input capacitor concerns the maximum input
voltage rating of the LT3493-3. A ceramic input capacitor
combined with trace or cable inductance forms a high
quality (underdamped) tank circuit. If the LT3493-3 circuit
is plugged into a live supply, the input voltage can ring to
twice its nominal value, possibly exceeding the LT3493-
3’s voltage rating. This situation is easily avoided; see the
Hot Plugging Safely section.
Output Capacitor
The output capacitor has two essential functions. Along
with the inductor, it filters the square wave generated by
the LT3493-3 to produce the DC output. In this role it
determines the output ripple so low impedance at the
switching frequency is important. The second function is
to store energy in order to satisfy transient loads and
stabilize the LT3493-3’s control loop.
Ceramic capacitors have very low equivalent series resis-
tance (ESR) and provide the best ripple performance. A
good value is:
COUT = 65/VOUT
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LT3494EDDB#PBF | 0.25 A SWITCHING REGULATOR, PDSO8 |
| LT3494EDDB | 0.25 A SWITCHING REGULATOR, PDSO8 |
| LT3502AEDC#PBF | 1.1 A SWITCHING REGULATOR, 2800 kHz SWITCHING FREQ-MAX, PDSO8 |
| LT3502AIDC#PBF | 1.1 A SWITCHING REGULATOR, 2800 kHz SWITCHING FREQ-MAX, PDSO8 |
| LT3502AIDC#TR | 1.1 A SWITCHING REGULATOR, 2800 kHz SWITCHING FREQ-MAX, PDSO10 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LT3493EDCBPBF | 制造商:LT 功能描述:Pb Free |
| LT3493EDCB-PBF | 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 |
| LT3493EDCB-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 |
| LT3493EDCBTRMPBF | 制造商:Linear Technology 功能描述:Sw. Regulator 1.2A 750kHz Step-Down DFN6 |
| LT3493EDCB-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 |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。