參數(shù)資料
型號: MIC2171BT
廠商: MICREL INC
元件分類: 穩(wěn)壓器
英文描述: Isolated Flyback Switching Regulator with 9V Output
中文描述: 5.5 A SWITCHING REGULATOR, 115 kHz SWITCHING FREQ-MAX, SFM5
封裝: TO-220, 5 PIN
文件頁數(shù): 9/10頁
文件大?。?/td> 80K
代理商: MIC2171BT
1997
4-11
MIC2171
Micrel
4
(10)
L
0.5 f
V
P
T
PRI
SW
IN(min)
2
ON
2
OUT
Where:
L
PRI
= maximum primary inductance
f
SW
= device switching frequency (100kHz)
V
IN(min)
= minimum input voltage
T
ON
= power switch on time
Then:
L
0.5
1 10
3.22
2.5
7.4 10
PRI
2
-62
×
×
)
×
L
PRI
11.4
μ
H
Use an 12
μ
H primary inductance to overcome circuit ineffi-
ciencies.
To complete the design the inductance value of the second-
ary is found which will guarantee that the energy stored in the
transformer during the power switch on time will be com-
pleted discharged into the output during the off-time. This is
necessary when operating in discontinuous-mode.
(11)
L
SEC
0.5 f
SW
V
SEC
2
T
OFF
2
P
OUT
Where:
L
SEC
= maximum secondary inductance
T
OFF
= power switch off time
Then:
L
0.5
1 10
5.41
2.5
2.6 10
SEC
-62
×
×
×
L
SEC
7.9
μ
H
Finally, recalculate the transformer turns ratio to insure that
it is less than the value earlier found in equation (9).
(12)
a
L
PRI
L
SEC
Then:
a
11.4
7.9 = 1.20
This ratio is less than the ratio calculated in equation (9).
When specifying the transformer it is necessary to know the
primary peak current which must be withstood without satu-
rating the transformer core.
(13)
I
PEAK(pri)
=
V
IN(min)
T
ON
L
PRI
So:
I
= 3.22
7.6 10
12 H
PEAK(pri)
-6
×
I
PEAK(pri)
= 2.1A
Now find the minimum reverse voltage requirement for the
output rectifier. This rectifier must have an average current
rating greater than the maximum output current of 0.5A.
(14)
V
BR
V
IN(max)
+ V
OUT
a
F
BR
a
)
Where:
V
BR
= output rectifier maximum peak
reverse voltage rating
a
= transformer turns ratio (1.2)
F
BR
= reverse voltage safety derating factor (0.8)
Then:
V
6.0 + 5.0
0.8
1.2
1.2
BR
×
)
×
V
BR
12.5V
A 1N5817 will safely handle voltage and current require-
ments in this example.
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參數(shù)描述
MIC2171BTL3 制造商:RF Micro Devices Inc 功能描述:
MIC2171BU 功能描述:IC REG MULTI CONFIG 2.5A TO263-5 RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標準包裝:20 系列:SIMPLE SWITCHER® 類型:降壓(降壓) 輸出類型:固定 輸出數(shù):1 輸出電壓:12V 輸入電壓:4 V ~ 60 V PWM 型:電壓模式 頻率 - 開關(guān):52kHz 電流 - 輸出:1A 同步整流器:無 工作溫度:-40°C ~ 125°C 安裝類型:通孔 封裝/外殼:16-DIP(0.300",7.62mm) 包裝:管件 供應(yīng)商設(shè)備封裝:16-DIP 其它名稱:*LM2575HVN-12LM2575HVN-12
MIC2171BU TR 功能描述:IC REG MULTI CONFIG 2.5A TO263-5 RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標準包裝:20 系列:SIMPLE SWITCHER® 類型:降壓(降壓) 輸出類型:固定 輸出數(shù):1 輸出電壓:12V 輸入電壓:4 V ~ 60 V PWM 型:電壓模式 頻率 - 開關(guān):52kHz 電流 - 輸出:1A 同步整流器:無 工作溫度:-40°C ~ 125°C 安裝類型:通孔 封裝/外殼:16-DIP(0.300",7.62mm) 包裝:管件 供應(yīng)商設(shè)備封裝:16-DIP 其它名稱:*LM2575HVN-12LM2575HVN-12
MIC2171WT 功能描述:直流/直流開關(guān)調(diào)節(jié)器 2.5A 100kHz Switching Regulator (ROHS Compliant) RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)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(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
MIC2171WU 功能描述:直流/直流開關(guān)調(diào)節(jié)器 2.5A 100kHz Switching Regulator (ROHS Compliant) RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)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(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5