- 您现在的位置：买卖IC网 > PDF目录1224 > LM5051MAEVAL/NOPB (National Semiconductor)BOARD EVAL FOR LM5051MA PDF资料下载
参数资料
| 型号： | LM5051MAEVAL/NOPB |
| 厂商： | National Semiconductor |
| 文件页数： | 13/23页 |
| 文件大小： | 0K |
| 描述： | BOARD EVAL FOR LM5051MA |
| 标准包装： | 1 |
| 主要目的： | 电源管理，O 环控制器/低压侧 |
| 嵌入式： | 否 |
| 已用 IC / 零件： | LM5051 |
| 已供物品： | 板 |
SNVS702D – OCTOBER 2011 – REVISED MARCH 2013
Several factors can prevent the nFGD pin from indicating that the external MOSFET is operating normally. If the
LM5051 is used to connect parallel, redundant power supplies, one of the connected supplies may hold the
INP/VSS pin voltage close enough to the LM5051 INN pin voltage that the V SD(TST) threshold is not exceeded.
Additionally, operating with a high output capacitance value and low output load current may require a significant
amount of time before the output load capacitance is discharged to the point where the V SD(TST) threshold is
crossed and the nFGD pin switches.
The status of the nFGD pin does not depend on the status of the OFF pin. The status of the nFGD pin depends
only on the voltage at the INN pin relative to the INP/VSS pin being above, or below, the V SD(TST) threshold
voltage.
The nFGD output pin requires pull-up to an external voltage source, and must not be pulled higher than 5.5V
above the INP/VSS pin. It is recommended that the nFGD pin is not required to sink more than 2mA.
VCC PIN
The VCC pin is connected to the cathode of the internal shunt (zener) voltage regulator. The anode of the shunt
regulator is connected to the INP/VSS pin. The VCC pin provides bias for internal circuitry, as well as gate drive
to the external MOSFET. The VCC pin should always be bypassed with a 0.1 μ F ceramic capacitor to the
INP/VSS pin.
Typically, the VCC pin is biased from the LINE pin, through the internal 50 k ? series resistor, when the available
V LINE voltage is not less than the 36V minimum operating voltage.
If the available LINE voltage is less than less than the 36V minimum operating voltage the VCC pin can be
biased through the use of an external resistor to an appropriate bias supply that is referenced to the INP/VSS
pin.
A minimum VCC pin bias current of 1 mA is recommended, with a recommended 10 mA maximum.
A design example for calculating the external resistor where the VCC pin will be biased from an 18V to 36V
supply (relative to the INP/VSS pin):
R BIAS = (V BIAS(MIN) - V Z ) / I BIAS(MIN)
R BIAS = (18V - 13V) / 1 mA
R BIAS = 5.0 k ?
(1)
(2)
(3)
Next, using the calculated R BIAS resistor value, verify that the VCC pin current will be no more than 10mA at the
maximum V BIAS voltage:
ICC = (V BIAS(MAX) - 13V) / R BIAS
ICC = (36V - 13V) / 5.0 k ?
ICC = 4.6 mA
Since the calculated 4.6 mA is less than the 10 mA maximum, the 5 k ? value for R BIAS is acceptable.
R BIAS
(4)
(5)
(6)
LINE
LM5051
VCC
INN
GATE INP/VSS
0.1 F
Figure 29. Using an External Resistor to Bias the VCC Pin
Copyright ? 2011–2013, Texas Instruments Incorporated
Product Folder Links: LM5051
13
相关PDF资料 |
PDF描述 |
|---|---|
| LMR020-0650-CCF9-1KIT2X | KIT DEV LMR020-0650, 120V |
| LMR040-1000-CCF9-1KIT2X | KIT DEV LMR4 1000 TRUEWHITE |
| LPSJ601.ZXID | FUSEHOLDER CLASS J 60A IND 1POLE |
| LR4-1300F | POLYSWITCH PTC RESET 13A STRAP |
| LR4-170UF | POLYSWITCH PTC RESET 1.7A STRAP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LM5051MAX/NOPB | 功能描述:热插拔功率分布 Lo Side OR-ing FET Cntlr RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube |
| LM5056 | 制造商:TI 制造商全称:Texas Instruments 功能描述:High-Voltage System Power Management Device with PMBusa?￠ |
| LM5056A | 制造商:TI 制造商全称:Texas Instruments 功能描述:High-Voltage System Power Management Device with PMBusa?￠ |
| LM5056APMH/NOPB | 功能描述:PMIC 解决方案 Hi Vtg System Pwr Mgmt IC RoHS:否 制造商:Texas Instruments 安装风格:SMD/SMT 封装 / 箱体:QFN-24 封装:Reel |
| LM5056APMHE/NOPB | 功能描述:PMIC 解决方案 Hi Vtg System Pwr Mgmt IC RoHS:否 制造商:Texas Instruments 安装风格:SMD/SMT 封装 / 箱体:QFN-24 封装:Reel |
发布紧急采购，3分钟左右您将得到回复。