參數資料
型號: LM2590HVT-5.0
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 穩(wěn)壓器
英文描述: SIMPLE SWITCHER Power Converter 150 kHz 1A Step-Down Voltage Regulator, with Features
中文描述: 3 A SWITCHING REGULATOR, 173 kHz SWITCHING FREQ-MAX, PZFM7
封裝: TO-220, 7 PIN
文件頁數: 16/20頁
文件大?。?/td> 752K
代理商: LM2590HVT-5.0
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 μH and f is in Hz. The maximum possible load
current I
is limited by the requirement that I
I
.
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
L
www.national.com
16
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相關代理商/技術參數
參數描述
LM2590HVT-ADJ 功能描述:直流/直流開關轉換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數量:2 最大工作溫度:+ 85 C 安裝風格:SMD/SMT
LM2590HVT-ADJ 制造商:Texas Instruments 功能描述:SWITCHING REG 1A ADJ 2590 TO2207
LM2590HVT-ADJ/NOPB 功能描述:直流/直流開關轉換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數量:2 最大工作溫度:+ 85 C 安裝風格:SMD/SMT
LM2591HVS-3.3 功能描述:直流/直流開關轉換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數量:2 最大工作溫度:+ 85 C 安裝風格:SMD/SMT
LM2591HVS-3.3/NOPB 功能描述:直流/直流開關轉換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數量:2 最大工作溫度:+ 85 C 安裝風格:SMD/SMT