参数资料
型号: LT3685EMSE#TRPBF
厂商: Linear Technology
文件页数: 17/24页
文件大小: 0K
描述: IC REG BUCK ADJ 2A 10MSOP
标准包装: 2,500
类型: 降压(降压)
输出类型: 可调式
输出数: 1
输出电压: 0.79 V ~ 20 V
输入电压: 3.6 V ~ 36 V
PWM 型: 电流模式
频率 - 开关: 200kHz ~ 2.4MHz
电流 - 输出: 2A
同步整流器:
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: 10-TFSOP,10-MSOP(0.118",3.00mm 宽)裸露焊盘
包装: 带卷 (TR)
供应商设备封装: 10-MSOP
LT3685
APPLICATIONS INFORMATION
a complete discussion). The low loss ceramic capacitor,
combined with stray inductance in series with the power
source, forms an under damped tank circuit, and the
voltage at the V IN pin of the LT3685 can ring to twice the
nominal input voltage, possibly exceeding the LT3685’s
rating and damaging the part. If the input supply is poorly
controlled or the user will be plugging the LT3685 into an
energized supply, the input network should be designed
to prevent this overshoot. Figure 9 shows the waveforms
that result when an LT3685 circuit is connected to a 24V
supply through six feet of 24-gauge twisted pair. The
?rst plot is the response with a 4.7μF ceramic capacitor
at the input. The input voltage rings as high as 50V and
the input current peaks at 26A. A good solution is shown
in Figure 9b. A 0.7 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. For high input voltages its impact on
ef?ciency is minor, reducing ef?ciency by 1.5 percent for
a 5V output at full load operating from 24V.
High Temperature Considerations
The PCB must provide heat sinking to keep the LT3685
cool. The Exposed Pad on the bottom of the package must
be soldered to a ground plane. This ground should be tied
to large copper layers below with thermal vias; these lay-
additional vias can reduce thermal resistance further. With
these steps, the thermal resistance from die (or junction)
to ambient can be reduced to JA = 35°C/W or less. With
100 LFPM air?ow, this resistance can fall by another 25%.
Further increases in air?ow will lead to lower thermal re-
sistance. Because of the large output current capability of
the LT3685, it is possible to dissipate enough heat to raise
the junction temperature beyond the absolute maximum of
125°C. When operating at high ambient temperatures, the
maximum load current should be derated as the ambient
temperature approaches 125°C.
Power dissipation within the LT3685 can be estimated by
calculating the total power loss from an ef?ciency measure-
ment and subtracting the catch diode loss and inductor
loss. The die temperature is calculated by multiplying the
LT3685 power dissipation by the thermal resistance from
junction to ambient.
Other Linear Technology Publications
Application Notes 19, 35 and 44 contain more detailed de-
scriptions and design information for buck regulators and
other switching regulators. The LT1376 data sheet has a more
extensive discussion of output ripple, loop compensation and
stability testing. Design Note 100 shows how to generate a
bipolar output supply using a buck regulator.
ers will spread the heat dissipated by the LT3685. Place
3685fb
17
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LT3685IDD#PBF 功能描述:IC REG BUCK ADJ 2A 10DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:250 系列:- 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON(1.45x1) 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2
LT3685IDD#TRPBF 功能描述:IC REG BUCK ADJ 2A 10DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压(升压) 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型,TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT
LT3685IDD-PBF 制造商:LINER 制造商全称:Linear Technology 功能描述:36V, 2A, 2.4MHz Step-Down Switching Regulator
LT3685IDD-TRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:36V, 2A, 2.4MHz Step-Down Switching Regulator
LT3685IMSE#PBF 功能描述:IC REG BUCK ADJ 2A 10MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:250 系列:- 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON(1.45x1) 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2