参数资料
型号: LM2590HV3.3MDC
厂商: NATIONAL SEMICONDUCTOR CORP
元件分类: 稳压器
英文描述: 3 A SWITCHING REGULATOR, 173 kHz SWITCHING FREQ-MAX, UUC
封装: DIE
文件页数: 8/24页
文件大小: 816K
代理商: LM2590HV3.3MDC
Application Information (Continued)
lNVERTING REGULATOR
The circuit in
Figure 10 converts a positive input voltage to a
negative output voltage with a common ground. The circuit
operates by bootstrapping the regulator’s ground pin to the
negative output voltage, then grounding the feedback pin,
the regulator senses the inverted output voltage and regu-
lates it.
This example uses the LM2590HV-5 to generate a 5V
output, but other output voltages are possible by selecting
other output voltage versions, including the adjustable ver-
sion. Since this regulator topology can produce an output
voltage that is either greater than or less than the input
voltage, the maximum output current greatly depends on
both the input and output voltage.
To determine how much load current is possible before the
internal device current limit is reached (and power limiting
occurs), the system must be evaluated as a buck-boost
configuration rather than as a buck. The peak switch current
in Amperes, for such a configuration is given as:
where L is in H and f is in Hz. The maximum possible load
current I
LOAD is limited by the requirement that IPEAK ≤ ICLIM.
While checking for this, take I
CLIM to be the lowest possible
current limit value (min across tolerance and temperature is
1.2A for the LM2590HV). Also to account for inductor toler-
ances, we should take the min value of Inductance for L in
the equation above (typically 20% less than the nominal
value). Further, the above equation disregards the drop
across the Switch and the diode. This is equivalent to as-
10134742
FIGURE 9. Typical Circuit Using Shutdown /Soft-start and Error Flag Features
10134743
FIGURE 10. Inverting 5V Regulator With Shutdown and Soft-start
LM2590HV
www.national.com
16
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相关代理商/技术参数
参数描述
LM2590HVS-3.3 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
LM2590HVS-3.3/NOPB 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
LM2590HVS-5.0 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
LM2590HVS5.0/NOPB 制造商:Texas Instruments 功能描述:
LM2590HVS-5.0/NOPB 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT