- 您现在的位置：买卖IC网 > PDF目录1833 > LTC3876EFE#PBF (Linear Technology)IC CTLR DC/DC DDR DUAL 38-TSSOP PDF资料下载
参数资料
| 型号： | LTC3876EFE#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 22/48页 |
| 文件大小： | 0K |
| 描述： | IC CTLR DC/DC DDR DUAL 38-TSSOP |
| 产品培训模块： | LTC3876 Dual DC/DC Controller |
| 标准包装： | 50 |
| 应用： | 控制器，DDR，DDR2，DDR3 |
| 输入电压： | 4.5 V ~ 38 V |
| 输出数： | 2 |
| 输出电压： | 可调 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 38-TFSOP （0.173"，4.40mm 宽）裸露焊盘 |
| 供应商设备封装： | 38-TSSOP 裸露焊盘 |
| 包装： | 管件 |
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页第41页第42页第43页第44页第45页第46页第47页第48页
LTC3876
APPLICATIONS INFORMATION
The previous discussion generally applies to high density/
high current applications where I OUT(MAX) > 10A and low
inductor values are used. For applications where I OUT(MAX)
V SENSE
20mV/DIV
500ns/DIV
3876 F04a
V ESL(STEP)
< 10A, set R F to 10Ω and C F to 1000pF. This will provide
a good starting point.
The filter components need to be placed close to the IC.
The positive and negative sense traces need to be routed
as a differential pair and Kelvin (4-wire) connected to the
sense resistor.
Figure 4a. Voltage Waveform Measured
Directly Across the Sense Resistor
V SENSE
20mV/DIV
DCR Inductor Current Sensing
For applications requiring higher efficiency at high load
currents, the LTC3876 is capable of sensing the voltage
drop across the inductor DCR, as shown in Figure 5. The
DCR of the inductor represents the small amount of DC
winding resistance, which can be less than 1mΩ for today’s
low value, high current inductors.
In a high current application requiring such an inductor,
conduction loss through a sense resistor would cost several
500ns/DIV
3876 F04b
points of efficiency compared to DCR sensing.
Figure 4b. Voltage Waveform Measured After the
Sense Resistor Filter. C F = 1000pF, R F = 100Ω
Note that the SENSE1 – and SENSE2 – pins are also used
for sensing the output voltage for the adjustment of top
gate on time, t ON . For this purpose, there is an additional
internal 500k resistor from each SENSE – pin to SGND,
therefore there is an impedance mismatch with their cor-
responding SENSE + pins. The voltage drop across the
R F causes an offset in sense voltage. For example, with
R F = 100Ω, at V OUT = V SENSE– = 5V, the sense-voltage
offset V SENSE(OFFSET) = V SENSE– ? R F /500k = 1mV. Such
small offset may seem harmless for current limit, but
The inductor DCR is sensed by connecting an RC filter
across the inductor. This filter typically consists of one or
two resistors (R1 and R2) and one capacitor (C1) as shown
in Figure 5. If the external (R1||R2) ? C1 time constant is
chosen to be exactly equal to the L/DCR time constant, the
voltage drop across the external capacitor is equal to the
voltage drop across the inductor DCR multiplied by R2/
(R1 + R2). Therefore, R2 may be used to scale the voltage
across the sense terminals when the DCR is greater than
INDUCTOR
could be significant for current reversal detection (I REV ),
L
DCR
V OUT
causing excess negative inductor current at discontinuous
mode. Also, at V SENSE(MAX) = 30mV, a mere 1mV offset
LTC3876
L/DCR = (R1||R2) C1
R1
C OUT
SENSE
will cause a significant shift of zero-current ITH voltage
by (2.4V – 0.8V) ? 1mV/30mV = 53mV. Too much shift
may not allow the output voltage to return to its regulated
SENSE +
–
C1
R2
(OPT)
3876 F05
value after the output is shorted due to ITH foldback.
Therefore, when a larger filter resistor R F value is used,
it is recommended to use an external 500k resistor from
each SENSE + pin to SGND, to balance the internal 500k
C1 NEAR SENSE PINS
Figure 5. DCR Current Sensing
resistor at its corresponding SENSE – pin.
3876f
22
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3878EGN#PBF | IC REG CTRLR BUCK PWM CM 16-SSOP |
| LTC3879EUD#PBF | IC REG CTRLR BUCK PWM CM 16-QFN |
| LTC3880EUJ-1#PBF | IC REG CTRLR BUCK PWM CM 40-QFN |
| LTC3890EUH#PBF | IC REG CTRLR BUCK PWM CM 32-QFN |
| LTC3891EFE#PBF | IC REG CTRLR BUCK PWM CM 20TSSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3876EUHF#PBF | 功能描述:IC CTLR DC/DC DDR DUAL 38-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| LTC3876EUHF#TRPBF | 功能描述:IC CTLR DC/DC DDR DUAL 38-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| LTC3876IFE#PBF | 功能描述:IC CTLR DC/DC DDR DUAL 38-TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| LTC3876IFE#TRPBF | 功能描述:IC CTLR DC/DC DDR DUAL 38-TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| LTC3876IUHF#PBF | 功能描述:IC CTLR DC/DC DDR DUAL 38-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
发布紧急采购，3分钟左右您将得到回复。