参数资料
型号: LT3640EUFD#PBF
厂商: LINEAR TECHNOLOGY CORP
元件分类: 稳压器
英文描述: 3.4 A DUAL SWITCHING CONTROLLER, 2350 kHz SWITCHING FREQ-MAX, PQCC28
封装: 5 X 4 MM, LEAD FREE, PLASTIC, MO-220, QFN-28
文件页数: 13/24页
文件大小: 506K
代理商: LT3640EUFD#PBF
LT3640
0
3640f
3640 F10
L2
L1
CIN2
CIN
CBST
COUT1
COUT2
Figure 9a shows the power-on reset timing. Having FB1
or FB2 high starts the CPOR oscillator. After tRST, the cor-
responding RST is released. When both RST1 and RST2
are released, the CWDT oscillator starts. Figure 9b shows
thewatchdogwaveformwiththeWDIperiodbetweentWDL
and tWDU.TheWDIfallingedgeresetstheCWDToscillator.
The CPOR oscillator is disabled and WDO remains high.
Figure 9c shows the watchdog waveform with the WDI
period longer than tWDU. WDO is asserted for a period of
tRST when the watchdog upper boundary, tWDU, expires.
PCB Layout
For proper operation and minimum EMI, care must be
taken during the printed circuit board (PCB) layout. Figure
10 shows the recommended component placement with
trace, ground plane and via locations. The input loop of
the high voltage channel, which is formed by the VIN
and SW1 pins, the external catch diode (D1), the input
capacitor (CIN) and the ground, should be as small as
possible. These external components should be placed
on the same side of the circuit board as the LT3640, and
their connections should be made on that layer. Place a
local, unbroken ground plane below these components.
The BST and SW nodes should be as small as possible.
The boost capacitor (CBST) should be as close to the BST
and SW pins as possible.
The input loop of the low voltage channel is formed by
the VIN2 pin, the input capacitor (CIN2) and the ground.
Place CIN2 close to the VIN2 and the GND pin to minimize
this loop. Place a local, unbroken ground plane below
this input loop.
Keep the FB1 and FB2 nodes small so that the ground
traces will shield them from the switching nodes. The
Exposed Pad on the bottom of the package must be sol-
dered to the ground so that the pad acts as a heat sink. To
keep thermal resistance low, extend the ground plane as
much as possible, and add thermal vias under and near
the LT3640 to additional ground planes within the circuit
board and on the bottom side.
Figure 10. Recommended PCB Layout, FE28 Package
applicaTions inForMaTion
相关PDF资料
PDF描述
LS4601-9RD2TB1 1-OUTPUT 100 W AC-DC PWR FACTOR CORR MODULE
LM3722E3.08MWC 1-CHANNEL POWER SUPPLY SUPPORT CKT, UUC
L4973D5.1-013TR 5.5 A SWITCHING REGULATOR, 300 kHz SWITCHING FREQ-MAX, PDSO20
LSM-1.5/16-W3 1-OUTPUT DC-DC REG PWR SUPPLY MODULE
LM3354MM-4.1/NOPB SWITCHED CAPACITOR REGULATOR, 1400 kHz SWITCHING FREQ-MAX, PDSO10
相关代理商/技术参数
参数描述
LT3640EUFDTRPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Monolithic Buck Regulator with Power-On Reset and Watchdog Timer
LT3640IFE 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Monolithic Buck Regulator with Power-On Reset and Watchdog Timer
LT3640IFE#PBF 功能描述:IC REG BUCK FIX/ADJ DL 28TSSOP 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
LT3640IFE#TRPBF 功能描述:IC REG BUCK FIX/ADJ DL 28TSSOP 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
LT3640IFEPBF 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Monolithic Buck Regulator with Power-On Reset and Watchdog Timer