参数资料
型号: LTC3780MPG#PBF
厂商: Linear Technology
文件页数: 24/30页
文件大小: 0K
描述: IC REG CTRLR BST PWM CM 24-SSOP
标准包装: 59
PWM 型: 电流模式
输出数: 1
频率 - 最大: 440kHz
占空比: 99%
电源电压: 4 V ~ 36 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -55°C ~ 125°C
封装/外壳: 24-SSOP(0.209",5.30mm 宽)
包装: 管件
LTC3780
APPLICATIONS INFORMATION
I IN , PEAK ( MAX , BUCK ) = 5 ? ? 1 +
? 29 % ?
2 ? ?
?
Double-check the T J in the MOSFET with 70°C ambient
temperature:
T J = 70°C + 1.94W ? 40°C/W = 147.6°C
The maximum power dissipation of switch B occurs in
buck mode. Assuming a junction temperature of T J = 80°C
with ρ 80°C = 1.2, the power dissipation at V IN = 18V is:
C IN is chosen to filter the square current in buck mode. In
this mode, the maximum input current peak is:
= 5 . 7 A
A low ESR (10mΩ) capacitor is selected. Input voltage
ripple is 57mV (assuming ESR dominate ripple).
P B,BUCK =
18 – 12
18
? 5 2 ? 1.2 ? 0.009 = 90mW
C OUT is chosen to filter the square current in boost mode.
In this mode, the maximum output current peak is:
? 5 ? ? 1 +
Double-check the T J in the MOSFET at 70°C ambient
temperature:
I OUT , PEAK ( MAX , BOOST ) =
12
5
?
?
11 % ?
2 ? ?
= 10 . 6 A
P C,BOOST = ( 12 – 5 ) ? 12 ? 5 2 ? 1.4 ? 0.009
+ 2 ? 12 3 ? ? 150p ? 400k = 1.27W
T J = 70°C + 0.09W ? 40°C/W = 73.6°C
The maximum power dissipation of switch C occurs in boost
mode. Assuming a junction temperature of T J = 110°C with
ρ 110°C = 1.4, the power dissipation at V IN = 5V is:
5 2
5
5
Double-check the T J in the MOSFET at 70°C ambient
temperature:
T J = 70°C + 1.08W ? 40°C/W = 113°C
The maximum power dissipation of switch D occurs
in boost mode when its duty cycle is higher than 50%.
Assuming a junction temperature of T J = 100°C with
ρ 100°C = 1.35, the power dissipation at V IN = 5V is:
A low ESR (5mΩ) capacitor is suggested. This capacitor
will limit output voltage ripple to 53mV (assuming ESR
dominate ripple).
PC Board Layout Checklist
The basic PC board layout requires a dedicated ground
plane layer. Also, for high current, a multilayer board
provides heat sinking for power components.
? The ground plane layer should not have any traces and
it should be as close as possible to the layer with power
MOSFETs.
? Place C IN , switch A, switch B and D1 in one com-
pact area. Place C OUT , switch C, switch D and D2 in
one compact area. One layout example is shown in
Figure 10.
5 ? 12
?
P D , BOOST = ? ? ? 5 ? ? 1 . 35 ? 0 . 009 = 0 . 73 W
2
12 ? 5 ?
Double-check the T J in the MOSFET at 70°C ambient
temperature:
T J = 70°C + 0.73W ? 40°C/W = 99°C
V IN
C IN
QA
D1
SW2
QB
L
SW1
QC
D2
QD
V OUT
C OUT
R SENSE
LTC3780
CKT
GND
3780 F10
Figure 10. Switches Layout
3780ff
24
For more information www.linear.com/LTC3780
相关PDF资料
PDF描述
NCP304LSQ27T1G IC VOLT DETECT CMOS 2.7V SC-82AB
RCC30DREF-S13 CONN EDGECARD 60POS .100 EXTEND
LTC1539CGW#TRPBF IC REG CTRLR BUCK PWM CM 36-SSOP
LTC1539CGW#TR IC REG CTRLR BUCK PWM CM 36-SSOP
NCP304LSQ25T1G IC VOLT DETECT CMOS 2.5V SC-82AB
相关代理商/技术参数
参数描述
LTC3783EDHD 制造商:Linear Technology 功能描述:LED DRVR 3.3V/5V/9V/12V/15V/18V/24V 16-Pin DFN EP
LTC3783EDHD#PBF 功能描述:IC LED DRIVER PWM CONTROL 16-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 标准包装:6,000 系列:- 恒定电流:- 恒定电压:- 拓扑:开路漏极,PWM 输出数:4 内部驱动器:是 类型 - 主要:LED 闪烁器 类型 - 次要:- 频率:400kHz 电源电压:2.3 V ~ 5.5 V 输出电压:- 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘 供应商设备封装:8-HVSON 包装:带卷 (TR) 工作温度:-40°C ~ 85°C 其它名称:935286881118PCA9553TK/02-TPCA9553TK/02-T-ND
LTC3783EDHD#TRPBF 功能描述:IC LED DRIVER PWM CONTROL 16-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 标准包装:6,000 系列:- 恒定电流:- 恒定电压:- 拓扑:开路漏极,PWM 输出数:4 内部驱动器:是 类型 - 主要:LED 闪烁器 类型 - 次要:- 频率:400kHz 电源电压:2.3 V ~ 5.5 V 输出电压:- 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘 供应商设备封装:8-HVSON 包装:带卷 (TR) 工作温度:-40°C ~ 85°C 其它名称:935286881118PCA9553TK/02-TPCA9553TK/02-T-ND
LTC3783EFE 制造商:Linear Technology 功能描述:LED DRVR 3.3V/5V/9V/12V/15V/18V/24V 16-Pin TSSOP EP
LTC3783EFE#PBF 功能描述:IC LED DRVR PWM CONTROL 16-TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - LED 驱动器 系列:- 标准包装:60 系列:- 恒定电流:- 恒定电压:- 拓扑:线性(LDO),PWM,升压(升压) 输出数:8 内部驱动器:是 类型 - 主要:背光 类型 - 次要:RGB,白色 LED 频率:500kHz ~ 1.5MHz 电源电压:4.75 V ~ 26 V 输出电压:45V 安装类型:* 封装/外壳:* 供应商设备封装:* 包装:* 工作温度:-40°C ~ 85°C