- 您现在的位置：买卖IC网 > PDF目录15288 > LTC3829EUHF#TRPBF (Linear Technology)IC REG CTRLR BUCK PWM CM 38-QFN PDF资料下载
参数资料
| 型号： | LTC3829EUHF#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 18/40页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 38-QFN |
| 标准包装： | 2,500 |
| 系列： | PolyPhase® |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 850kHz |
| 占空比： | 94% |
| 电源电压： | 4.5 V ~ 38 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 封装/外壳： | 38-WFQFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
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页当前第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页
LTC3829
APPLICATIONS INFORMATION
R = R O ? exp ? B ? ?
?
? T + 273 T O + 273 ? ? ?
TheNTCresistorhasanegativetemperaturecoefficient,
meaning its value decreases as temperature rises. The
V ITEMP voltage, therefore, decreases as temperature in-
creases and in turn, the V SENSEMAX(ADJ) will increase to
compensate the DCR temperature coefficient. The NTC
resistor, however, is nonlinear and the user can linear-
ize its value by building a resistor network with regular
resistors. Consult the NTC manufacture data sheets for
detailed information.
Another use for the ITEMP pins, in addition to NTC com-
pensated DCR sensing, is adjusting V SENSE(MAX) to values
between the nominal values of 30mV, 50mV and 75mV for
a more precise current limit. This is done by applying a
voltage less than 0.5V to the ITEMP pin. V SENSE(MAX) will
be varied per the previous equation and the same duty cycle
limitations will apply. The current limit can be adjusted using
this method either with a sense resistor or DCR sensing.
NTC Compensated DCR Sensing
For DCR sensing applications where a more accurate
current limit is required, a network consisting of an NTC
thermistor placed from the ITEMP pin to ground will
provide correction of the current limit over temperature.
Figure 2b shows this network. Resistors R S and R P will
linearize the impedance the ITEMP pin sees. To implement
NTC compensated DCR sensing, design the DCR sense
filter network per the same procedure mentioned in the
previous selection, except calculate the divider components
using the room temperature value of the DCR. For a single
output rail operating from one phase:
1. Set the ITEMP pin resistance to 50k at 25°C. With
10μA flowing out of the ITEMP pin, the voltage on the
ITEMP pin will be 0.5V at room temperature. Current
limit correction will occur for inductor temperatures
greater than 25°C.
2. Calculate the ITEMP pin resistance and the maximum
inductor temperature which is typically 100°C. Use the
equations:
Calculate the values for R P and R S . A simple method is to
graph the following R S versus R P equations with R S on
the y-axis and R P on the x-axis.
R S = R ITEMP25C – R NTC25C || R P
R S = R ITEMP100C – R NTC100C || R P
Next, find the value of R P that satisfies both equations
which will be the point where the curves intersect. Once
R P is known, solve for R S .
The resistance of the NTC thermistor can be obtained
from the vendor’s data sheet either in the form of graphs,
tabulated data or formulas. The approximate value for the
NTC thermistor for a given temperature can be calculated
from the following equation:
? ? 1 1 ? ?
–
?
where:
R = resistance at temperature T, which is in degrees C
R O = resistance at temperature T O , typically 25°C
B = B-constant of the thermistor.
Figure 5 shows a typical resistance curve for a 100k therm-
istor and the ITEMP pin network over temperature.
Starting values for the NTC compensation network are
listed below:
? NTC R O = 100k
? R S = 20k
? R P = 50k
But, the final values should be calculated using the above
equations and checked at 25°C and 100°C.
R ITEMP100C =
V ITEMP100C
10μA
V ITEMP100C = 0.5V – 1.3 MAX
18
I
? DCR(MAX) ? R2 / ( R1 + R2 ) ? ( 100 ° C – 25 ° C ) ? 0.4 / 100
V SENSE(MAX)
For more information www.linear.com/LTC3829
3829fa
相关PDF资料 |
PDF描述 |
|---|---|
| GBM43DTMN | CONN EDGECARD 86POS R/A .156 SLD |
| RLB9012-561KL | INDUCTOR HI CURRENT RADIAL 560UH |
| LTC3862IUH#TRPBF | IC REG CTRLR BST PWM CM 24-QFN |
| GBM43DTMD | CONN EDGECARD 86POS R/A .156 SLD |
| RLB9012-471KL | INDUCTOR HI CURRENT RADIAL 470UH |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3829IFE#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 38TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:PolyPhase® 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
| LTC3829IFE#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 38TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:PolyPhase® 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
| LTC3829IUHF#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 38-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:PolyPhase® 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
| LTC3829IUHF#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 38-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:PolyPhase® 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 V 降压:是 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
| LTC3830-1ES8 | 功能描述:IC REG CTRLR BUCK PWM VM 8-SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,000 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:1MHz 占空比:50% 电源电压:9 V ~ 10 V 降压:无 升压:是 回扫:是 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:无 工作温度:-40°C ~ 85°C 封装/外壳:8-TSSOP（0.173"，4.40mm 宽） 包装:带卷 (TR) |
发布紧急采购，3分钟左右您将得到回复。