- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄384734 > MIC2171BU (MICREL INC) Isolated Flyback Switching Regulator with 9V Output PDF資料下載
參數(shù)資料
| 型號： | MIC2171BU |
| 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, PSSO5 |
| 封裝： | TO-263, 5 PIN |
| 文件頁數(shù)： | 10/10頁 |
| 文件大?。?/td> | 80K |
| 代理商： | MIC2171BU |
MIC2171
Micrel
4-12
1997
D3
1N5819
MIC2171
IN
SW
FB
COMP
C1
22μF
C3
1μF
R2
1k
V
OUT
5V, 1A
R4
3.74k
1%
R5
1.24k
1%
C5
470μF
L1 100μH
V
IN
12V
GND
T1
1:1:1
D4
1N5819
D2
1N5819
* Voltage clipper
Duty cycle limiter
D1*
C2*
Q1
C4
R3
R1*
Figure 7. MIC2171 Forward Converter
Forward Converters
Micrel’s MIC2171 can be used in several circuit configura-
tions to generate an output voltage which is less than the input
voltage (buck or step-down topology). Figure 7 shows the
MIC2171 in a voltage step-down application. Because of the
internal architecture of these devices, more external compo-
nents are required to implement a step-down regulator than
with other devices offered by Micrel (refer to the LM257x or
MIC457x family of buck switchers). However, for step-down
conversion requiring a transformer (forward), the MIC2171 is
a good choice.
A 12V to 5V step-down converter using transformer isolation
(forward) is shown in Figure 7. Unlike the isolated flyback
converter which stores energy in the primary inductance
during the controller’s on-time and releases it to the load
during the off-time, the forward converter transfers energy to
the output during the on-time, using the off-time to reset the
transformer core. In the application shown, the transformer
core is reset by the tertiary winding discharging T1’s peak
magnetizing current through D2.
For most forward converters the duty cycle is limited to 50%,
allowing the transformer flux to reset with only two times the
input voltage appearing across the power switch. Although
during normal operation this circuit’s duty cycle is well below
50%, the MIC2172 has a maximum duty cycle capability of
90%. If 90% was required during operation (start-up and high
load currents), a complete reset of the transformer during the
off-time would require the voltage across the power switch to
be ten times the input voltage. This would limit the input
voltage to 6V or less for forward converter applications.
To prevent core saturation, the application given here uses a
duty cycle limiter consisting of Q1, C4 and R3. Whenever the
MIC2171 exceeds a duty cycle of 50%, T1’s reset winding
current turns Q1 on. This action reduces the duty cycle of the
MIC2171 until T1 is able to reset during each cycle.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MIC2171 | Isolated Flyback Switching Regulator with 9V Output |
| MIC2185 | Low Voltage Synchronous Boost PWM Control IC |
| MIC2185BM | Low Voltage Synchronous Boost PWM Control IC |
| MIC2185BQS | Low Voltage Synchronous Boost PWM Control IC |
| MIC2193 | 400KHZ SO 8 SYNCHRONOUS BUCK CONTROL IC |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| 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(biāo)準(zhǔn)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 |
| MIC2171WU TR | 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-TR | 功能描述:Buck, Boost, Cuk, Flyback, Forward Converter Switching Regulator IC Positive or Negative, Isolation Capable Adjustable 1 Output 2.5A (Switch) TO-263-6, D2Pak (5 Leads + Tab), TO-263BA 制造商:microchip technology 系列:- 包裝:剪切帶（CT） 零件狀態(tài):有效 功能:升壓，降壓，升壓/降壓 輸出配置:正或負(fù)，可提供隔離 拓?fù)?降壓，升壓，Cuk，反激，正激轉(zhuǎn)換器 輸出類型:可調(diào)式 輸出數(shù):1 電壓 - 輸入（最小值）:3V 電壓 - 輸入（最大值）:40V 電壓 - 輸出（最小值/固定）:- 電壓 - 輸出（最大值）:65V（開關(guān)） 電流 - 輸出:2.5A（開關(guān)） 頻率 - 開關(guān):100kHz 同步整流器:無 工作溫度:-40°C ~ 85°C（TA） 安裝類型:表面貼裝 封裝/外殼:TO-263-6，D2Pak（5 引線+接片），TO-263BA 供應(yīng)商器件封裝:TO-263-5 標(biāo)準(zhǔn)包裝:1 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。