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參數(shù)資料
| 型號： | L4974A |
| 廠商： | 意法半導體 |
| 英文描述： | Power Switching Regulator(功率開關穩(wěn)壓器) |
| 中文描述： | 電源開關穩(wěn)壓器（功率開關穩(wěn)壓器） |
| 文件頁數(shù)： | 3/22頁 |
| 文件大?。?/td> | 378K |
| 代理商： | L4974A |
PINFUNCTIONS
N
o
1
Name
Function
BOOTSTRAP
A C
boot
capacitor connected between this terminal and the output allows to drive
properly the internal D-MOS transistor.
A C
d
capacitor connected between this terminal and ground determines the reset
signaldelay time.
Open Collector Reset/power Fail Signal Output. This output ishigh when the supply
and the output voltages are safe.
Input of PowerFail Circuit. The threshold is 5.1V. It may be connected via a divider
to theinput for power failfunction. Itmustbe connected tothepin14anexternal 30K
resistorwhen power fail signal not required.
Common Ground Terminal
2
RESET DELAY
3
RESET OUT
4
RESET INPUT
5, 6
15, 16
7
GROUND
FREQUENCY
COMPENSATION
SOFT START
A series RC network connected between this terminal and ground determines the
regulation loop gain characteristics.
Soft Start Time Constant. A capacitor is connected between thi sterminal and ground
to define the soft start time constant.
The Feedback Terminal of the Regulation Loop. The output is connected directly to
this terminal for 5.1V operation; It isconnected via a dividerfor higher voltages.
Multiple L4974A’s are synchronized by connecting pin 10 inputs together or via an
external syncr. pulse.
Unregulated Input Voltage.
Not Connected.
5.1V V
ref
Device Reference Voltage.
Internal Start-up Circuit to Drive the PowerStage.
R
osc
. External resistor connected toground determines the constant charging current
of C
osc
.
C
osc
. External capacitor connected to ground determines (with R
osc
) the switching
frequency.
Regulator Output.
8
9
FEEDBACK INPUT
10
SYNC INPUT
11
SUPPLY VOLTAGE
N.C.
V
ref
V
start
OSCILLATOR
12, 19
13
14
17
18
OSCILLATOR
20
OUTPUT
L4974A
3/22
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PDF描述 |
|---|---|
| L4975A | Power Switching Regulator(功率開關穩(wěn)壓器) |
| L4976 | 1A Step Down Switching Regulator(步降開關穩(wěn)壓器) |
| L4977A | Power Switching Regulator(功率開關穩(wěn)壓器) |
| L4978D | Isolated Flyback Switching Regulator with 9V Output |
| L4978 | 2A Step Down Switching Regulator(步降開關穩(wěn)壓器) |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| L4974A | 制造商:STMicroelectronics 功能描述:IC SWITCHING REG 3.5A 4974 DIP20 |
| L4974AE | 制造商:STMicroelectronics 功能描述: |
| L4975 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:5A SWITCHING REGULATOR |
| L4975A | 功能描述:直流/直流開關調(diào)節(jié)器 5.1 to 40V Step-Down RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5 |
| L4975A | 制造商:STMicroelectronics 功能描述:SWITCHING REG 5A 4975 MULTIWATT15 |
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