参数资料
| 型号： | LT3493IDCB#TRMPBF |
| 厂商： | Linear Technology |
| 文件页数： | 15/20页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK ADJ 1.2A 6DFN |
| 标准包装： | 500 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.78 V ~ 34.2 V |
| 输入电压： | 3.6 V ~ 36 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 750kHz |
| 电流 - 输出： | 1.2A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 6-WFDFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 6-DFN-EP（2x3） |
LT3493
APPLICATIONS INFORMATION
a 2.2μF ceramic capacitor at the input. The input voltage
rings as high as 35V and the input current peaks at 20A.
One method of damping the tank circuit is to add another
capacitor with a series resistor to the circuit. In Figure 9b
an aluminum electrolytic capacitor has been added. This
capacitor’s high equivalent series resistance damps the
circuit and eliminates the voltage overshoot. The extra
capacitor improves low frequency ripple ?ltering and can
slightly improve the ef?ciency of the circuit, though it is
likely to be the largest component in the circuit. An alterna-
tive solution is shown in Figure 9c. A 1Ω resistor is added
in series with the input to eliminate the voltage overshoot
(it also reduces the peak input current). A 0.1μF capacitor
improves high frequency ?ltering. This solution is smaller
and less expensive than the electrolytic capacitor. For high
input voltages its impact on ef?ciency is minor, reducing
ef?ciency less than one half percent for a 5V output at full
load operating from 24V.
CLOSING SWITCH
SIMULATES HOT PLUG
Frequency Compensation
The LT3493 uses current mode control to regulate the
output. This simpli?es loop compensation. In particular,
the LT3493 does not require the ESR of the output capaci-
tor for stability allowing the use of ceramic capacitors to
achieve low output ripple and small circuit size.
Figure 10 shows an equivalent circuit for the LT3493 control
loop. The error amp is a transconductance ampli?er with
?nite output impedance. The power section, consisting of
the modulator, power switch and inductor, is modeled as
a transconductance ampli?er generating an output cur-
rent proportional to the voltage at the V C node. Note that
the output capacitor integrates this current, and that the
capacitor on the V C node (C C ) integrates the error ampli-
?er output current, resulting in two poles in the loop. R C
provides a zero. With the recommended output capacitor,
the loop crossover occurs above the R C C C zero. This simple
I IN
V IN
DANGER!
+
LT3493
2.2μF
V IN
20V/DIV
RINGING V IN MAY EXCEED
ABSOLUTE MAXIMUM
RATING OF THE LT3493
I IN
LOW
IMPEDANCE
ENERGIZED
24V SUPPLY
STRAY
INDUCTANCE
DUE TO 6 FEET
(2 METERS) OF
TWISTED PAIR
LT3493
(9a)
5A/DIV
V IN
20μs/DIV
+
10μF
35V
+
2.2μF
20V/DIV
AI.EI.
I IN
5A/DIV
1Ω
(9b)
20μs/DIV
+
LT3493
V IN
20V/DIV
0.1μF
2.2μF
I IN
5A/DIV
(9c)
20μs/DIV
3493 F09
Figure 9. A Well Chosen Input Network Prevents Input Voltage Overshoot and
Ensures Reliable Operation When the LT3493 is Connected to a Live Supply
3493fb
15
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| LT3495EDDB-1#TRMPBF | IC REG BOOST ADJ 0.35A 10DFN |
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| LT3502IMS#TRPBF | IC REG BUCK ADJ 0.5A 10MSOP |
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3493IDCB-TRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:1.2A, 750kHz Step-Down Switching Regulator in 2mm × 3mm DFN |
| LT3494 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Micropower Low Noise Boost Converters with Output Disconnect |
| LT3494A | 制造商:LINER 制造商全称:Linear Technology 功能描述:20mA LED Driver and OLED Driver with Integrated Schottky in 3mm x 2mm DFN |
| LT3494AEDDB | 制造商:LINER 制造商全称:Linear Technology 功能描述:Micropower Low Noise Boost Converters with Output Disconnect |
| LT3494AEDDB#PBF | 制造商:Linear Technology 功能描述:BOOST 2.3 - 16V 0.35A 40V 制造商:Linear Technology 功能描述:BOOST, 2.3 - 16V, 0.35A, 40V, 20QFN |
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