参数资料
| 型号： | SC4525ASETRT |
| 厂商： | Semtech |
| 文件页数： | 12/19页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK 3A 8SOIC |
| 标准包装： | 1 |
| 类型： | 降压（降压） |
| 输出数： | 1 |
| 输入电压： | 8 V ~ 28 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 300kHz ~ 1.3MHz |
| 电流 - 输出： | 3A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm Width）裸露焊盘 |
| 包装： | 标准包装 |
| 供应商设备封装： | 8-SOIC-EP |
| 产品目录页面： | 1358 (CN2011-ZH PDF) |
| 其它名称： | SC4525ASEDKR |
Fig 5
Applications Information (Cont.)
SS270 REV 6-7
SC4525A
diodes should have an average forward current rating
at least 3A and a reverse blocking voltage of at least a
few volts higher than the input voltage. For switching
regulators operating at low duty cycles (i.e. low output
voltage to input voltage conversion ratios), it is beneficial
to use freewheeling diodes with somewhat higher
average current ratings (thus lower forward voltages). This
is because the diode conduction interval is much longer
than that of the transistor. Converter efficiency will be
improved if the voltage drop across the diode is lower.
The freewheeling diode should be placed close to the
2.2
2.1
2.0
1.9
1.8
1.7
1.6
Minimum Bootstrap Voltage
vs Temperature
I SW =-3.9A
SW pin of the SC4525A to minimize ringing due to trace
inductance. 20BQ030 (International Rectifier), B320A,
-50
-25
0 25 50 75
Temperature ( o C)
100 125
B330A (Diodes Inc.), SS33 (Vishay), CMSH3-20MA and
CMSH3-40MA (Central-Semi.) are all suitable.
Figure 5. Typical Minimum Bootstrap Voltage required
to Saturate Transistor (I SW = -3.9A)
The freewheeling diode should be placed close to the SW
D1
D3
pin of the SC4525A on the PCB to minimize ringing due to
BST
C1
trace inductance.
VIN
IN
SW
VOUT
VIN
2
Bootstrapping the Power Transistor
The minimum BST-SW voltage required to fully saturate
SC4525A
GND
D
powered from either the input or the output of the
thepowertransistorisshowninFigure4,whichisabout
.98V at room temperature.
D1
The BST-SW voltage is supplied by a bootstrap circuit
BST C1
D3
D1
BST
(a)
C1
converter (Figure 5). To maximize SW
efficiency, tie the VOUT
bootstrap diode to the converter output if V O >2.5V.
Since the bootstrap supply current is proportional to the
SC4525A
2
2
VIN
IN
D
GND
converter load current (Equation ( 0), page 4), using a
VIN
IN
SW
SC4525A
GND
D
VOUT
lower voltage to power the bootstrap circuit reduces
driving loss and improves efficiency.
(a)
(b)
Figure 6. Methods of Bootstrapping the SC4525A
For the bootstrap circuit, a fast switching PN diode (such
as N4 48 or N9 4) and a small (0. μF – 0.47μF) ceramic
capacitor is sufficient for most applications. When
bootstrapping from 2.5V to 3.0V output voltages, use a
low forward drop Schottky diode (BAT-54 or similar) for
D . When bootstrapping from high input voltages (>20V),
reduce the maximum BST voltage by connecting a Zener
diode (D 3 ) in series with D .
Loop Compensation
The goal of compensation is to shape the frequency
response of the converter so as to achieve high DC
accuracy and fast transient response while maintaining
loop stability.
2
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相关代理商/技术参数 |
参数描述 |
|---|---|
| SC4525C | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:28V 3A Step-Down Switching Regulator Thermal Shutdown |
| SC4525CSETRT | 功能描述:IC REG BUCK ADJ 3A 8SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:250 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON（1.45x1） 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2 |
| SC4525D | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:18V, 3A, 350kHz Step-Down Switching Regulator |
| SC4525DEVB | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:18V, 3A, 350kHz Step-Down Switching Regulator |
| SC4525DSETRT | 功能描述:IC REG BUCK ADJ 3A 8SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 类型:升压（升压） 输出类型:两者兼有 输出数:1 输出电压:5V，2 V ~ 16.5 V 输入电压:2 V ~ 16.5 V PWM 型:- 频率 - 开关:45kHz 电流 - 输出:50mA 同步整流器:无 工作温度:0°C ~ 70°C 安装类型:通孔 封装/外壳:8-DIP（0.300"，7.62mm） 包装:管件 供应商设备封装:8-PDIP |
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