参数资料
| 型号： | NCP5387MNR2G |
| 厂商： | ON Semiconductor |
| 文件页数： | 35/37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
Vout + Zout + RFB · DCR · 6
RDRP + RFB · DCR · 6
RFB should be set to provide optimal thermal
compensation in conjunction with thermistor RT2, RISO1
and RISO2. With RFB set to 1.0 k W , RFB1 is usually set to
100 W for maximum phase boost, and 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 introduces an
offset which is proportional to the output current thereby
forcing a controlled, resistive output impedance.
RRDP determines the target output impedance by the
basic equation:
Iout RDRP
(eq. 10)
Zout
The value of the inductor ’s DCR varies with temperature
according to the following equation 11:
DCR(T) + DCR25C · (1 ) 0.00393(T?25))
(eq. 11)
The system can be thermally compensated to cancel this
effect 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 total value for RISO1 plus RISO2
is approximately 1.0 k W .
The output impedance varies with inductor temperature by the equation:
Zout(T) +
RFB · DCR25C · (1 ) 0.00393(T?25)) · 6
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(T?25)) · 6
Rdroop
(eq. 13)
RT2(T) + RT225C · e b
*
1 1
273 ) T
The typical equation of a NTC is based on a curve fit
equation 14.
(eq. 14)
298
The demo board is populated with a 10 k W NTC with a
Beta of 4300. Figure 39 shows the uncompensated and
compensated output impedance versus temperature.
VRHOT and VRFAN
The NCP5387 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.
The following equations can be used to find the
temperature trip points.
RT1(T) + RT125C · e b
1
273 ) T
*
1
298
(eq. 15)
RatioNTC(T) :
RNTC2 ) RT1(T)
RNTC1 ) RNTC2 ) RT1(T)
(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 40 is a plot of
Figure 39. Uncompensated and Compensated Output
Impedance vs. Temperature
equation 16. The horizontal, trip threshold voltages
intersect the Ratio NTC curve at the respective activation
and deactivation 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
be verified with an actual system thermal solution.
http://onsemi.com
35
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 |
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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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