参数资料
| 型号： | NCP5386AMNR2G |
| 厂商： | ON Semiconductor |
| 文件页数： | 28/33页 |
| 文件大小： | 0K |
| 描述： | IC CTLR BUCK 1/2PHASE 32-QFN |
| 标准包装： | 2,500 |
| 应用： | 控制器，Intel VR10、VR11、AMD CPU |
| 输入电压： | 4.75 V ~ 5.25 V |
| 输出数： | 2 |
| 工作温度： | 0°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 32-VFQFN 裸露焊盘 |
| 供应商设备封装： | 32-QFN（5x5） |
| 包装： | 带卷 (TR) |
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NCP5386, NCP5386A, NCP5386B
Programming the Current Limit and the
Oscillator Frequency
The demo board is set for an operating frequency of
approximately 330 kHz. The OSC pin provides a 2.0 V
reference voltage which is divided down with a resistor
to create an oscillator. The period is proportional to the
resistance and frequency is inversely proportional to the
resistance. The resistance may be estimated by equation 2.
divider and fed into the current limit pin ILIM. Calculate
the total series resistance to set the frequency and then
calculate the individual values for current limit divider.
The series resistors RLIM1 and RLIM2 sink current to
R TOTAL ^ 24686
30.5 k W ^ 24686
F SW ? 1.1549
330 ? 1.1549
(eq. 2)
ground. This current is internally mirrored into a capacitor
100
90
80
70
60
50
40
30
20
10
FOSC (2 F , Measured)
FOSC (2 F , Calculated)
0
0
200
400
600
800
1000
1200
FOSC (kHz)
Figure 30. ROSC vs. FOSC, 2 Phase
The current limit function is based on the total sensed
current of all phases multiplied by a gain of 6. DCR sensed
based on the expected average maximum temperature of
the inductor windings.
inductor current is function of the winding temperature.
The best approach is to set the maximum current limit
Calculate the current limit voltage:
DCRTmax + DCR25C ·
(1 ) 0.00393 · C ? 1 (T max ? 25 · C))
(eq. 3)
V ILIMIT ^ 6 ·
I MIN_OCP · DCR Tmax )
DCR Tmax · V out
2 · V IN · F s
·
V IN * V OUT
L
* (N ? 1) ·
V OUT
L
(eq. 4)
Solve for the individual resistors:
RLIM2 +
VILIMIT · RTOTAL
2·V
(eq. 5)
RLIM1 + R TOTAL * R LIM2
(eq. 6)
Final Equation for the Current Limit Threshold
ILIMIT(Tinductor) ^
2 · V · RLIM2
RLIM1 ) RLIM2
5.84 · (DCR 25C · (1 ) 0.00393 · C ? 1 (T Inductor ? 25 · C)))
*
V OUT
2 · V IN · Fs
·
V IN ? V OUT
L
* (N ? 1) ·
V OUT
L
(eq. 7)
The inductors on the demo board have a DCR at 25 ° C of
0.75 m W . Selecting the closest available values of 16.9 k W
for RLIM1 and 13.7 k W for RLIM2 yield a nominal
operating frequency of 330 kHz and an approximate
current limit of 152 A at 100 ° C. The total sensed current
can be observed as a scaled voltage at the VDRP pin added
to a positive, no ? load offset of approximately 1.3 V.
Inductor Selection
When using inductor current sensing it is recommended
that the inductor does not saturate by more than 10% at
maximum load. The inductor also must not go into hard
saturation before current limit trips. The demo board includes
a two phase output filter using the T50 ? 8 core from
Micrometals with 4turns and a DCR target of 0.75 m W @
25 ° C. Smaller DCR values can be used, however, current
sharing accuracy and droop accuracy decrease as DCR
http://onsemi.com
28
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相关代理商/技术参数 |
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|---|---|
| NCP5386B | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:1/2 Phase Controller for CPU and Chipset Applications |
| NCP5386BMNR2G | 功能描述:软开关 PWM 控制器 1/2 PHASE CONTROLLER RoHS:否 制造商:Fairchild Semiconductor 输出端数量: 输出电流: 开关频率: 工作电源电压:30 V 电源电流: 最大工作温度:+ 105 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel |
| NCP5386MNR2G | 功能描述:软开关 PWM 控制器 1/2 PHASE CONTROLLER RoHS:否 制造商:Fairchild Semiconductor 输出端数量: 输出电流: 开关频率: 工作电源电压:30 V 电源电流: 最大工作温度:+ 105 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel |
| NCP5386SMNR2G | 制造商:ON Semiconductor 功能描述: |
| NCP5387 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:2/3/4 Phase Controller for CPU Applications |
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