- 您现在的位置：买卖IC网 > PDF目录44993 > LTC3810IG#TR (LINEAR TECHNOLOGY CORP) SWITCHING CONTROLLER, PDSO28 PDF资料下载
参数资料
| 型号： | LTC3810IG#TR |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 稳压器 |
| 英文描述： | SWITCHING CONTROLLER, PDSO28 |
| 封装： | 5.30 MM, PLASTIC, SSOP-28 |
| 文件页数： | 7/36页 |
| 文件大小： | 495K |
| 代理商： | LTC3810IG#TR |
第1页第2页第3页第4页第5页第6页当前第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
LTC3810
15
3810fb
The basic LTC3810 application circuit is shown on the rst
page of this data sheet. External component selection is
primarily determined by the maximum input voltage and
load current and begins with the selection of the sense
resistance and power MOSFET switches. The LTC3810
uses either a sense resistor or the on-resistance of the
synchronous power MOSFET for determining the inductor
current. The desired amount of ripple current and operating
frequency largely determines the inductor value. Next, CIN
is selected for its ability to handle the large RMS current
into the converter and COUT is chosen with low enough
ESR to meet the output voltage ripple and transient
specication. Finally, loop compensation components
are selected to meet the required transient/phase margin
specications.
Maximum Sense Voltage and VRNG Pin
Inductor current is determined by measuring the volt-
age across a sense resistance that appears between the
SENSE– and SENSE+ pins. The maximum sense voltage
is set by the voltage applied to the VRNG pin and is equal
to approximately:
VSENSE(MAX) = 0.173VRNG – 0.026
The current mode control loop will not allow the inductor
current valleys to exceed VSENSE(MAX)/RSENSE. In prac-
tice, one should allow some margin for variations in the
LTC3810 and external component values and a good guide
for selecting the sense resistance is:
RSENSE =
VSENSE(MAX)
1.3 IOUT(MAX)
An external resistive divider from INTVCC can be used
to set the voltage of the VRNG pin between 0.5V and 2V
resulting in nominal sense voltages of 60mV to 320mV.
Additionally, the VRNG pin can be tied to SGND or INTVCC
in which case the nominal sense voltage defaults to 95mV
or 215mV, respectively.
Connecting the SENSE+ and SENSE– Pins
The LTC3810 can be used with or without a sense resis-
tor. When using a sense resistor, place it between the
source of the bottom MOSFET, M2, and PGND. Connect
the SENSE+ and SENSE– pins to the top and bottom of
the sense resistor. Using a sense resistor provides a well
dened current limit, but adds cost and reduces efciency.
Alternatively, one can eliminate the sense resistor and use
the bottom MOSFET as the current sense element by simply
connecting the SENSE+ pin to the lower MOSFET drain
and SENSE– pin to the MOSFET source. This improves
efciency, but one must carefully choose the MOSFET
on-resistance, as discussed below.
Power MOSFET Selection
The LTC3810 requires two external N-channel power
MOSFETs, one for the top (main) switch and one for the
bottom (synchronous) switch. Important parameters for
the power MOSFETs are the breakdown voltage BVDSS,
threshold voltage V(GS)TH, on-resistance RDS(ON), input
capacitance and maximum current IDS(MAX).
When the bottom MOSFET is used as the current sense
element, particular attention must be paid to its on-resis-
tance. MOSFET on-resistance is typically specied with
a maximum value RDS(ON)(MAX) at 25°C. In this case,
additional margin is required to accommodate the rise in
MOSFET on-resistance with temperature:
RDS(ON)(MAX) =
RSENSE
T
The
ρT term is a normalization factor (unity at 25°C)
accounting for the signicant variation in on-resistance
with temperature (see Figure 5) and typically varies
from 0.4%/°C to 1.0%/°C depending on the particular
MOSFET used.
Figure 5. RDS(ON) vs Temperature
APPLICATIONS INFORMATION
JUNCTION TEMPERATURE (°C)
–50
ρ
TNORMALIZED
ON-RESISTANCE
1.0
1.5
150
3810 F05
0.5
0
50
100
2.0
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3810EG | SWITCHING CONTROLLER, PDSO28 |
| LTC3812EFE-5 | 1 A SWITCHING CONTROLLER, PDSO16 |
| LTC3812IFE-5#TR | 1 A SWITCHING CONTROLLER, PDSO16 |
| LTC3812EFE-5#TR | 1 A SWITCHING CONTROLLER, PDSO16 |
| LTC3812IFE-5 | 1 A SWITCHING CONTROLLER, PDSO16 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3810IUH-5#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 32-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 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) |
| LTC3810IUH-5#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 32-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 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) |
| LTC3811EG#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP 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) |
| LTC3811EG#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP 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) |
| LTC3811EUHF#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) |
发布紧急采购，3分钟左右您将得到回复。