- 您现在的位置：买卖IC网 > PDF目录14838 > LT3437EFE#PBF (Linear Technology)IC REG BUCK ADJ 0.5A 16TSSOP PDF资料下载
参数资料
| 型号： | LT3437EFE#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 22/28页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK ADJ 0.5A 16TSSOP |
| 标准包装： | 95 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 1.25 V ~ 54 V |
| 输入电压： | 3.3 V ~ 60 V |
| PWM 型： | 电流模式，混合 |
| 频率 - 开关： | 200kHz |
| 电流 - 输出： | 500mA |
| 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： | 16-TSSOP（0.173"，4.40mm）裸露焊盘 |
| 包装： | 管件 |
| 供应商设备封装： | 16-TSSOP-EP |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页当前第22页第23页第24页第25页第26页第27页第28页
LT3437
APPLICATIO S I FOR ATIO
( ) ( V OUT ) + t EFF ( 1 / 2 )( I OUT )( V IN )( f )
THERMAL CALCULATIONS
Power dissipation in the LT3437 chip comes from four
sources: switch DC loss, switch AC loss, boost circuit
current, and input quiescent current. The following formu-
las show how to calculate each of these losses. These
formulas assume continuous mode operation, and should
not be used for calculating efficiency at light load currents.
Switch loss:
2
R SW I OUT
P SW =
V IN
Boost current loss:
Thermal resistance for the LT3437 package is influenced
by the presence of internal or backside planes. With a full
plane under the package, thermal resistance will be about
45 ° C for the FE and DD packages. No plane will increase
resistance to about 150 ° C/W. To calculate die temperature,
use the proper thermal resistance number for the desired
package and add in worst-case ambient temperature:
T J = T A + Q JA (P TOT )
With the DD package (Q JA = 45 ° C/W) at an ambient
temperature of 70 ° C:
T J = 70 + 45(0.1) = 74.5 ° C
HIGH TEMPERATURE OPERATION
P BOOST =
( V OUT ) 2 ( I OUT /30 )
V IN
Extreme care must be taken when designing LT3437
applications to operate at high ambient temperatures. The
LT3437 is designed to work at elevated temperatures but
Quiescent current loss:
P Q = V IN (500 μ A) + V OUT (800 μ A)
R SW = switch resistance ( ≈ 1 when hot )
t EFF = effective switch current/voltage overlap time
(t r + t f + t IR + t IF )
t r = (V IN /0.6)ns
t f = (V IN /2)ns
t IR = t IF = (I OUT /0.05)ns
f = switch frequency
Example: with V IN = 40V, V OUT = 5V and I OUT = 250mA:
erratic operation can occur due to external components.
Each passive component should be checked for absolute
value and voltage ratings to ensure loop stability at tem-
perature. Boost and Catch diode leakages, as well as
increased series resistance, will adversely affect efficiency
and low quiescent current operation. Junction tempera-
ture increase in the diodes due to self heating (leakage)
and power dissipation should be measured to ensure their
maximum temperature specifications are not violated.
Input Voltage vs Operating Frequency Considerations
The absolute maximum input supply voltage for the LT3437
is specified at 80V. This is based solely on internal semi-
( )( ) ( ) 5 +
1 0 . 25
P SW =
40
2
/
( 92 )( 12 )( 0 . 25 )( 40 )( 200 e 3 )
conductor junction breakdown effects. Due to internal
power dissipation, the actual maximum V IN achievable in
a particular application may be less than this.
0 . 008 + 0 . 092 = 0 . 1 W
P BOOST = ( 5 ) 2 ( 0 . 25 / 30 ) = 0 . 005 W
40
P Q = 40 ( 0 . 0005 ) + 5 ( 0 . 0008 ) = 0 . 024 W
Total power dissipation is:
P TOT = 0.1 + 0.065 + 0.024 = 0.13W
A detailed theoretical basis for estimating internal power
loss is given in the section Thermal Considerations. Note
that AC switching loss is proportional to both operating
frequency and output current. The majority of AC switch-
ing loss is also proportional to the square of input voltage.
For example, while the combination of V IN = 40V, V OUT =
5V at 700mA and f OSC = 200kHz may be easily achievable,
simultaneously raising V IN to 80V and f OSC to 700kHz is not
possible. Nevertheless, input voltage transients up to 80V
can usually be accommodated, assuming the resulting
3437fc
22
相关PDF资料 |
PDF描述 |
|---|---|
| RBC19DREN-S734 | CONN EDGECARD 38POS .100 EYELET |
| ISC1812ER681J | INDUCTOR WW 680UH 5% 1812 |
| PM2120-221K | INDUCTOR TOROID 220UH 10% SMD |
| ISC1812ER471J | INDUCTOR WW 470UH 5% 1812 |
| LTC1751EMS8#PBF | IC REG SWITCHD CAP DBL ADJ 8MSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3437HFE | 制造商:LINER 制造商全称:Linear Technology 功能描述:High Voltage 500mA, 200kHz Step-Down Switching Regulator with 100μA Quiescent Current |
| LT3437HFE#PBF | 功能描述:IC REG BUCK ADJ 0.5A 16TSSOP 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 |
| LT3437HFE#TRPBF | 功能描述:IC REG BUCK ADJ 0.5A 16TSSOP 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:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 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 裸露焊盘 |
| LT3437IDD | 制造商:Linear Technology 功能描述:SP-SWREG/Monolithic, 60V, 500mA, 200kHz Step-down Converter w/ BurstMode |
| LT3437IDD#PBF | 功能描述:IC REG BUCK ADJ 0.5A 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 |
发布紧急采购，3分钟左右您将得到回复。