参数资料
型号: LT3508HUF#PBF
厂商: Linear Technology
文件页数: 18/26页
文件大小: 0K
描述: IC REG BUCK ADJ 1.4A DL 24QFN
标准包装: 91
类型: 降压(降压)
输出类型: 可调式
输出数: 2
输出电压: 0.8 V ~ 35.3 V
输入电压: 3.7 V ~ 36 V
PWM 型: 电流模式
频率 - 开关: 920kHz ~ 1.06MHz
电流 - 输出: 1.4A
同步整流器:
工作温度: -40°C ~ 150°C
安装类型: 表面贴装
封装/外壳: 24-WFQFN 裸露焊盘
包装: 管件
供应商设备封装: 24-QFN 裸露焊盘(4x4)
产品目录页面: 1331 (CN2011-ZH PDF)
LT3508
APPLICATIONS INFORMATION
LT3508 is absent. This may occur in battery charging
applications or in battery back-up systems where a battery
or some other supply is diode OR-ed with the LT3508’s
output. If the V IN pin is allowed to ?oat and the SHDN pin
is held high (either by a logic signal or because it is tied
to V IN ), then the LT3508’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 V IN pin is grounded while the output
is held high, then parasitic diodes inside the LT3508 can
pull large currents from the output through the SW pin
and the V IN pin. Figure 10 shows a circuit that will run
only when the input voltage is present and that protects
against a shorted or reversed input.
PARASITIC DIODE
PCB Layout
For proper operation and minimum EMI, care must be taken
during printed circuit board layout. Figure 11 shows the
recommended PCB layout with trace and via locations. Note
that large, switched currents ?ow in the LT3508’s V IN and
SW pins, the catch diode (D1) and the input capacitor (C IN ).
The loop formed by these components should be as small
as possible. These components, along with the inductor
and output capacitor, should be placed on the same side
of the circuit board, and their connections should be made
on that layer. Place a local, unbroken ground plane below
these components. The SW and BOOST nodes should be
as small as possible. Finally, keep the FB and V C nodes
small so that the ground traces will shield them from the
SW and BOOST nodes. The exposed pad on the bottom of
the package must be soldered to ground so that the pad
acts as a heat sink. To keep thermal resistance low, extend
V IN
D4
V IN
SW
V OUT
the ground plane as much as possible, and add thermal
vias under and near the LT3508 to additional ground planes
LT3508
3508 F10
Figure 10. Diode D4 Prevents a Shorted Input from Discharging
a Backup Battery Tied to the Output
(11a) Example Layout for FE16 Package
within the circuit board and on the bottom side.
(11b) Example Layout for QFN Package
Figure 11. A Good PCB Layout Ensures Proper Low EMI Operation
3508fd
18
相关PDF资料
PDF描述
RBC22DCMT CONN EDGECARD 44POS .100 WW
LTC1475IS8#PBF IC REG BUCK ADJ 0.75A 8SOIC
RCC36DCMS CONN EDGECARD 72POS .100 WW
LTC1574CS#PBF IC REG BUCK INV ADJ 16SOIC
RCC22DCAT CONN EDGECARD 44POS R/A .100 SLD
相关代理商/技术参数
参数描述
LT3508HUF-TRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Monolithic 1.4A Step-Down Switching Regulator
LT3508IFE#PBF 功能描述:IC REG BUCK ADJ 1.4A DL 16TSSOP 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
LT3508IFE#TRPBF 功能描述:IC REG BUCK ADJ 1.4A DL 16TSSOP 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
LT3508IFEPBF 制造商:Linear Technology 功能描述:Sw. Regulator Dual 1.4A Step-Down TSSOP
LT3508IFE-PBF 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Monolithic 1.4A Step-Down Switching Regulator