- 您现在的位置：买卖IC网 > PDF目录17095 > FPF2700MX (Fairchild Semiconductor)IC LOAD SWITCH CURR LIMIT 8-SOIC PDF资料下载
参数资料
| 型号： | FPF2700MX |
| 厂商： | Fairchild Semiconductor |
| 文件页数： | 14/19页 |
| 文件大小： | 0K |
| 描述： | IC LOAD SWITCH CURR LIMIT 8-SOIC |
| 标准包装： | 1 |
| 系列： | AccuPower™ |
| 类型： | 通用 |
| 输出数： | 1 |
| Rds（开）： | 114 毫欧 |
| 内部开关： | 是 |
| 电流限制： | 可调 |
| 输入电压： | 2.8 V ~ 36 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽） |
| 供应商设备封装： | 8-SO |
| 包装： | 标准包装 |
| 其它名称： | FPF2700MXDKR |
Input Capacitor
To limit the voltage drop on the input supply caused by
transient inrush currents when the switch is turned on
into a discharged load capacitor or short-circuit; an input
capacitor, C IN , is recommended between the IN and
GND pins. The FPF270X features a fast current limit
response time (50 μs). During this period , the device
relies on the input capacitor to supply the load current. A
Power Dissipation
During normal operation as a switch, the power
dissipation of the device is small and has little effect on
the operating temperature of the part. The maximum
power dissipation for the switch in normal operation
occurs just before the switch enters into current limit.
This may be calculated using the equation:
10 μF to 100 μF ceramic capacitor is ade quate for C IN in
P D _ MAX ( NormalOper ation ) ? ( I LIM ( Max ) ) 2 ? R ON ( MAX )
(3)
most cases. Larger C IN values may be required in high-
voltage or high-current applications. An electrolytic
capacitor can be used in parallel to further reduce the
voltage drop.
T he maximum junction temperature should be limited to
125°C under normal operation. Junction temperature
can be calculated using the equation:
Output Capacitor
T J ? P D ? ? JA ? T A
(4)
A 0.1 μF to 1 μF capacitor, C OUT , should be placed
between the OUT and GND pins. This capacitor helps
prevent parasitic board inductances from forcing the
output voltage below ground when the switch turns
off. This capacitor should have a low dissipation
where:
? T J is junction temperature;
? P D is power dissipation on the switch;
? Θ JA is the thermal resistance, junction-to-ambient of
factor. An X7R Multilayer Ceramic Chip (MLCC)
capacitor is recommended.
During startup, the total output current consists of both
?
the package; and
T A is ambient temperature.
the load current and the charge current of the output
capacitor. For the FPF2700 and FPF2701; if the total
output current exceeds the set current limit threshold
(determined via R SET ) for longer than the blanking time,
Design Example
For a 12 V application and I LIM (Max) = 1 A, maximum
power dissipation in a normal operation is calculated as:
the device may not be able to start properly. This
imposes an upper limit to the value of the output
P D _ MAX ( NormalOper ation )( VIN ? 12 V ) ? ( 1 ) 2 ? 0 . 140 ? 140 mW
(5)
capacitor, given the load current and the selected
current limit value. C OUT should not exceed the C OUTmax
calculated in Equation 2 or the switch does not start
properly due to the set current limit:
FPF2702 P D(Max) during OC:
If device is in over-current condition and V OUT >2 V,
power dissipation can be calculated as:
C OUT max ? I LIM _ MIN ? 500 ? s / V
(2)
P D = (V IN - V OUT ) x I LIM (Max)
(6)
High-Voltage Operation (Output Capacitor)
During a hard short condition on the output while
If device is in short-circuit current limit and V OUT < 2 V,
power dissipation can be calculated as:
operating at greater than 24 V
V IN , a large
P D = (V IN - V OUT ) x (0.75 x I LIM (Max) )
(7)
instantaneous inrush current is delivered to the shorted
output. A capacitor must be placed at the OUTPUT
pin, acting as a current source to support the
instantaneous current draw (Table 2). A low-ESR
capacitor is recommended. Once the value of the
output capacitor is determined from Table 2, Equation
Design Example:
Using FPF2702 in a V IN = 5 V application where I LIM (Max)
= 2 A, assuming V OUT = 2.5 V; power dissipation across
the switch is calculated as:
2 must be reevaluated.
P D = (5 - 2.5) x 2 = 5W
(8)
Table 2.
C OUT Selection Guide
Whereas in a short-circuit current-limit condition (V OUT ≈
V IN (V)
Capacitance ( μ F)
0 V), power dissipation is calculated as:
24< V IN ≤ 27
27< V IN ≤ 32
22
47
P D = ((V IN - V OUT ) x (0.75 x I LIM (Max) ) = (5 - 0) x
(0.75 x 2) = 7.5W
(9)
32< V IN ≤ 36
? 2010 Fairchild Semiconductor Corporation
FPF2700 / FPF2701 / FPF2702 ? Rev. 1.0.3
68
14
www.fairchildsemi.com
相关PDF资料 |
PDF描述 |
|---|---|
| HW-V4-ML405-UNI-G | EVALUATION PLATFORM VIRTEX-4 |
| GBB05DHFT | CONN CARDEDGE 10POS .050" SMD |
| SDR-9 | SCOTCH CODE REFILL # 9 |
| HW-V4-ML402-UNI-G | EVALUATION PLATFORM VIRTEX-4 |
| EEV-HA1A221XP | CAP ALUM 220UF 10V 20% SMD |
相关代理商/技术参数 |
参数描述 |
|---|---|
| FPF2701MPX | 功能描述:电源开关 IC - POE / LAN AccuPower Advanced Load Mngmnt Products RoHS:否 制造商:Fairchild Semiconductor 开关数量:Single 开关配置:SPST 开启电阻（最大值）:7.3 Ohms 串话: 带宽: 开启时间（最大值）:13 ns 关闭时间（最大值）:20 ns 切换电压（最大）: 工作电源电压:8 V to 26 V 最大工作温度:+ 125 C 安装风格:Through Hole 封装 / 箱体:TO-220F-6 |
| FPF2701MX | 功能描述:电源开关 IC - POE / LAN AccuPower Advanced Load Mngmnt Products RoHS:否 制造商:Fairchild Semiconductor 开关数量:Single 开关配置:SPST 开启电阻（最大值）:7.3 Ohms 串话: 带宽: 开启时间（最大值）:13 ns 关闭时间（最大值）:20 ns 切换电压（最大）: 工作电源电压:8 V to 26 V 最大工作温度:+ 125 C 安装风格:Through Hole 封装 / 箱体:TO-220F-6 |
| FPF2702MPX | 功能描述:电源开关 IC - POE / LAN AccuPower Advanced Load Mngmnt Products RoHS:否 制造商:Fairchild Semiconductor 开关数量:Single 开关配置:SPST 开启电阻（最大值）:7.3 Ohms 串话: 带宽: 开启时间（最大值）:13 ns 关闭时间（最大值）:20 ns 切换电压（最大）: 工作电源电压:8 V to 26 V 最大工作温度:+ 125 C 安装风格:Through Hole 封装 / 箱体:TO-220F-6 |
| FPF2702MX | 功能描述:电源开关 IC - POE / LAN AccuPower Advanced Load Mngmnt Products RoHS:否 制造商:Fairchild Semiconductor 开关数量:Single 开关配置:SPST 开启电阻（最大值）:7.3 Ohms 串话: 带宽: 开启时间（最大值）:13 ns 关闭时间（最大值）:20 ns 切换电压（最大）: 工作电源电压:8 V to 26 V 最大工作温度:+ 125 C 安装风格:Through Hole 封装 / 箱体:TO-220F-6 |
| FPF28 | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Analog IC |
发布紧急采购，3分钟左右您将得到回复。