参数资料
| 型号： | NCP5388MNR2G |
| 厂商： | ON Semiconductor |
| 文件页数： | 32/34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 13/June/2008 Product Discontinuation 30/Sept/2011 |
| 标准包装： | 2,500 |
| 应用： | 控制器，Intel Pentium? IV |
| 输入电压： | 10.8 V ~ 13.2 V |
| 输出数： | 4 |
| 工作温度： | 0°C ~ 70°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（7x7） |
| 包装： | 带卷 (TR) |
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NCP5388
Vout + Zout + RFB · DCR · 5.94
Iout RDRP
RFB · DCR · 5.94
RDRP +
RFB is always set to 1.0 k W and RFB1 is usually set to
100 W for maximum phase boost. The value of RF is
typically set to 4.0 k W .
Droop Injection and Thermal Compensation
The VDRP signal is generated by summing the sensed
output currents for each phase and applying a gain of
approximately six. VDRP is externally summed into the
feedback network by the resistor RDRP. This induces an
offset which is proportional to the output current thereby
forcing the controlled resistive output impedance.
RRDP determines the target output impedance by the
basic equation:
(eq.
10)
Zout
The value of the inductor ’s DCR varies with temperature
according to the following equation 10:
DCRTmax + DCR25C · (1 ) 0.00393 · C ? 1(TTmax ? 25 · C))
(eq. 11)
The system can be thermally compensated to cancel this
effect out to a great degree by adding an NTC (negative
temperature coefficient resistor) in parallel with RFB to
reduce the droop gain as the temperature increases. The
NTC device is nonlinear. Putting a resistor in series with the
NTC helps make the device appear more linear with
temperature. The series resistor is split and inserted on both
sides of the NTC to reduce noise injection into the feedback
loop. The recommended value for RISO1 and RISO2 is
approximately 1.0 k W .
The output impedance varies with inductor temperature by the equation:
Zout(T) +
RFB · DCR25C · (1 ) 0.00393 · C ? 1(T max ? 25C)) · 5.94
Rdroop
(eq. 12)
By including the NTC RT2 and the series isolation resistors the new equation becomes:
Zout(T) +
RFB · (RISO1 ) RT2(T) ) RISO2)
RFB ) RISO1 ) RT2(T) ) RISO2
· DCR25C · (1 ) 0.00393 · C ? 1(T max ? 25C)) · 5.94
Rdroop
(eq. 13)
1 1
RT2(T) + RT225C · e b
*
298
273 ) T
The typical equation of a NTC is based on a curve fit
equation 13.
(eq. 14)
The demo board is populated with a 10 k W NTC with a
Beta of 4300. Figure 21 shows the uncompensated and
compensated output impedance versus temperature.
VRHOT and VRFAN
Thermal monitoring provides two threshold sensitive
comparators for thermal monitoring. The circuit consists of
two comparators that compare the voltage on the NTC pin
to an internal resistor divider connected to VREF. By
powering the external temperature sense divider with
VREF the tolerance of the VREF voltage is canceled out.
The data sheet specifications for the thresholds are shown
as ratios with respect to VREF.
VR_FAN Upper Threshold Ratio = 0.3625
VR_FAN Lower Threshold Ratio = 0.3025
VR_HOT Upper Threshold Ratio = 0.2815
VR_HOT Lower Threshold Ratio = 0.2190
The following equations can be used to find the
temperature trip points.
RT1(T) + RT125C · e b
1
273 ) T
*
1
298
(eq. 15)
RNTC2 ) RT1(T)
RatioNTC(T) :
RNTC1 ) RNTC2 ) RT1(T)
Figure 21. Uncompensated and Compensated Output
Impedance vs. Temperature
ON Semiconductor provides an excel spreadsheet to
help with the selection of the NTC. The actual selection of
the NTC will be effected by the location of the output
inductor with respect to the NTC and airflow, and should
(eq. 16)
The demo board contains a 68 K NTC for RT1 with a
Beta of 4750. RNTC1 is populated with 15 k W and RNTC2
is populated with a zero ohm resistor. Figure 22 is a plot of
equation 15. The horizontal trip thresholds intersect the
Ratio NTC curve.
be verified with an actual system thermal solution.
http://onsemi.com
32
相关PDF资料 |
PDF描述 |
|---|---|
| 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 |
| NCP5392TMNR2G | IC PHASE CONTROLLER 2/3/4 40-QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 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 |
| NCP5391MNR2G | 功能描述:软开关 PWM 控制器 2/3 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 |
| NCP5392 | 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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