- 您现在的位置：买卖IC网 > PDF目录1832 > LTC3836EUFD#TRPBF (Linear Technology)IC REG CTRLR BUCK PWM CM 28-QFN PDF资料下载
参数资料
| 型号： | LTC3836EUFD#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 21/30页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 28-QFN |
| 标准包装： | 2,500 |
| 系列： | PolyPhase® |
| PWM 型： | 电流模式 |
| 输出数： | 2 |
| 频率 - 最大： | 825kHz |
| 占空比： | 97% |
| 电源电压： | 2.75 V ~ 4.5 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 ~ 85°C |
| 封装/外壳： | 28-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页第18页第19页第20页当前第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
LTC3836
APPLICATIONS INFORMATION
Using a Sense Resistor
A sense resistor R SENSE can be connected between V IN
and SW to sense the output load current. In this case, the
drain of the topside N-channel MOSFET is connected to
SENSE – pin and the source is connected to the SW pin of
the LTC3836. Therefore, the current comparator monitors
the voltage developed across R SENSE , not the V DS of the
top MOSFET. The output current that the LTC3836 can
provide in this case is given by:
V IN decreases below 3V. Figure 12 shows the amount of
change as the supply is reduced down to 2.4V. Also
shown is the effect on V REF .
Minimum On-Time Considerations
Minimum on-time, t ON(MIN) , is the smallest amount of time
that the LTC3836 is capable of turning the main N-chan-
nel MOSFET on and then off. It is determined by internal
timing delays and the gate charge required to turn on the
V SENSE(MAX) I RIPPLE
R DS(ON)
I OUT(MAX) =
–
2
top MOSFET. Low duty cycle and high frequency applica-
tions may approach the minimum on-time limit and care
should be taken to ensure that:
Setting ripple current as 40% of I OUT(MAX) and using
Figure 1 to choose SF, the value of R SENSE is:
t ON(MIN) <
V OUT
f OSC ? V IN
R SENSE = ? SF ?
5
6
V SENSE(MAX)
I OUT(MAX)
If the duty cycle falls below what can be accommodated
by the minimum on-time, the LTC3836 will begin to skip
Variation in the resistance of a sense resistor is much
smaller than the variation in on-resistance of an external
MOSFET. Therefore the load current is well controlled with
a sense resistor. However the sense resistor causes extra
I 2 R losses in addition to those of the MOSFET. Therefore,
using a sense resistor lowers the ef?ciency of LTC3836,
especially at high load currents.
Low Supply Operation
Although the LTC3836 can function down to below 2.4V,
the maximum allowable output current is reduced as
105
cycles (unless forced continuous mode is selected). The
output voltage will continue to be regulated, but the ripple
current and ripple voltage will increase. The minimum on-
time for the LTC3836 is typically about 200ns. However,
as the peak sense voltage (I L(PEAK) ? R DS(ON) ) decreases,
the minimum on-time gradually increases up to about
250ns. This is of particular concern in forced continuous
applications with low ripple current at light loads. If forced
continuous mode is selected and the duty cycle falls below
the minimum on-time requirement, the output will be
regulated by overvoltage protection.
100
95
V REF
MAXIMUM
SENSE VOLTAGE
90
85
80
75
2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0
INPUT VOLTAGE (V)
3836 F12
Figure 12. Line Regulation of V REF and
Maximum Sense Voltage for Low Input Supply
3836fb
21
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3838IFE#TRPBF | IC REG CTRLR BUCK PWM CM 38TSSOP |
| LTC3839EUH#PBF | IC REG CTRLR BUCK PWM CM 32-QFN |
| LTC3850IGN-2#TRPBF | IC REG CTRLR BUCK PWM CM 28-SSOP |
| LTC3850IGN#PBF | IC REG CTRLR BUCK PWM CM 28-SSOP |
| LTC3851EGN#PBF | IC REG CTRLR BUCK PWM CM 16-SSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3838EFE#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: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) |
| LTC3838EFE#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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR) |
| LTC3838EUHF#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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR) |
| LTC3838EUHF#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:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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:24-WQFN 裸露焊盘 包装:带卷 (TR) |
| LTC3838EUHF-1#PBF | 制造商:Linear Technology 功能描述:IC REG CTRLR BUCK PWM CM 38QFN 制造商:Linear Technology 功能描述:BUCK DUAL CNTRL 4.5-38V 2MHZ 38QFN 制造商:Linear Technology 功能描述:BUCK, DUAL, CNTRL, 4.5-38V, 2MHZ, 38QFN 制造商:Linear Technology 功能描述:DC-DC CONTROLLER, DUAL, BUCK, ADJ, QFN-38, Primary Input Voltage:38V, No. of Outputs:2, Output Current:25A, No. of Pins:38, Operating Temperature Min:-40C, Operating Temperature Max:125C, MSL:MSL 1 - Unlimited , RoHS Compliant: Yes 制造商:Linear Technology 功能描述:DP-SWREG/Controller, Dual, Fast, Accurate Step-Down Controller with Differential |
发布紧急采购，3分钟左右您将得到回复。