参数资料
| 型号： | NCP5387MNR2G |
| 厂商： | ON Semiconductor |
| 文件页数： | 32/37页 |
| 文件大小： | 0K |
| 描述： | IC CTLR BUCK 2/3/4PHASE 40-QFN |
| 产品变化通告： | Specification Change MSL Updated 28/Feb/2008 |
| 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： | 4 |
| 工作温度： | 0°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 40-VFQFN 裸露焊盘 |
| 供应商设备封装： | 40-QFN（6x6） |
| 包装： | 带卷 (TR) |
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NCP5387
Programming the Current Limit and the
Oscillator Frequency
The demo board is set for an operating frequency of
approximately 330 kHz. The ROSC pin provides a 2.0 V
reference voltage which is divided down with a resistor
divider and fed into the current limit pin ILIM. Calculate
the total series resistance to set the frequency and then
proportional to the resistance and frequency is inversely
proportional to the total resistance. The total resistance
may be estimated by equation 2. This equation is valid for
the individual phase frequency in both three and four phase
mode.
calculate the individual RLIM1 and RLIM2 values for the
divider.
The series resistors RLIM1 and RLIM2 sink current from
the ILIM pin to ground. This current is internally mirrored
RTOTAL ^ 24686
30.5 · k W ^ 24686
Fsw?1.1549
330?1.1549
(eq. 2)
into a capacitor to create an oscillator. The period is
Figure 35.
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 (T max ?25))
(eq. 3)
· Vin?Vout * (N?1) · Vout
VILIMIT ^ 6 · IMIN_OCP · DCRTmax )
DCRTmax · Vout
2 · Vin · Fsw
L L
(eq. 4)
Solve for the individual resistors:
RLIM2 + ILIMIT
V · RTOTAL
2·V
(eq. 5)
RLIM1 + RTOTAL?RLIM2
(eq. 6)
Final Equation for the Current Limit Threshold
2 · V · RLIM2
· Vin?Vout * (N?1) · Vout
ILIMIT(Tinductor) ^
RLIM1 ) RLIM2
6 · (DCR25C · (1 ) 0.00393(TInductor?25)))
*
Vout
2 · Vin · Fsw
L 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 four 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
decreases. Use the excel spreadsheet for regulation accuracy
calculations for a specific value of DCR.
http://onsemi.com
32
相关PDF资料 |
PDF描述 |
|---|---|
| NCP5388MNR2G | IC CTLR BUCK 2/3/4PHASE 40-QFN |
| NCP5389MNR2G | IC CTLR BUCK 2/3PHASE 32-QFN |
| NCP5391MNR2G | IC CTLR BUCK 2/3PHASE 32-QFN |
| NCP5392PMNR2G | IC CTLR BUCK 2/3/4PHASE 40QFN |
| NCP5392QMNR2G | IC PHASE CONTROLLER 2/3/4 40-QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| NCP5388 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:2/3/4 Phase Buck Controller for VR10 and VR11 Pentium IV Processor Applications |
| NCP5388MNR2G | 功能描述:其他电源管理 2/3/4 PHASE CNTRLLR RoHS:否 制造商:Texas Instruments 输出电压范围: 输出电流:4 mA 输入电压范围:3 V to 3.6 V 输入电流: 功率耗散: 工作温度范围:- 40 C to + 110 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-48 封装:Reel |
| NCP5389 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:2/3 Phase Buck Controller for VR11 Pentium IV Processor Applications |
| NCP5389MNR2G | 功能描述:IC CTLR BUCK 2/3PHASE 32-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,000 系列:- 应用:电源，ICERA E400，E450 输入电压:4.1 V ~ 5.5 V 输出数:10 输出电压:可编程 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:42-WFBGA，WLCSP 供应商设备封装:42-WLP 包装:带卷 (TR) |
| NCP5391 | 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:2/3 Phase Buck Controller for VR11 Pentium IV Processor Applications |
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