参数资料
型号: LM2576-3.3MDC
厂商: NATIONAL SEMICONDUCTOR CORP
元件分类: 稳压器
英文描述: 7.5 A SWITCHING REGULATOR, 63 kHz SWITCHING FREQ-MAX, UUC
封装: DIE
文件页数: 10/27页
文件大小: 741K
代理商: LM2576-3.3MDC
Additional Applications (Continued)
DELAYED STARTUP
The ON /OFF pin can be used to provide a delayed startup
feature as shown in
Figure 14. With an input voltage of 20V
and for the part values shown, the circuit provides approxi-
mately 10 ms of delay time before the circuit begins switch-
ing. Increasing the RC time constant can provide longer de-
lay times. But excessively large RC time constants can
cause problems with input voltages that are high in 60 Hz or
120 Hz ripple, by coupling the ripple into the ON /OFF pin.
ADJUSTABLE OUTPUT, LOW-RIPPLE POWER SUPPLY
A 3A power supply that features an adjustable output voltage
is shown in
Figure 15. An additional L-C filter that reduces
the output ripple by a factor of 10 or more is included in this
circuit.
Definition of Terms
BUCK REGULATOR
A switching regulator topology in which a higher voltage is
converted to a lower voltage. Also known as a step-down
switching regulator.
BUCK-BOOST REGULATOR
A switching regulator topology in which a positive voltage is
converted to a negative voltage without a transformer.
DUTY CYCLE (D)
Ratio of the output switch’s on-time to the oscillator period.
CATCH DIODE OR CURRENT STEERING DIODE
The diode which provides a return path for the load current
when the LM2576 switch is OFF.
EFFICIENCY (
η)
The proportion of input power actually delivered to the load.
CAPACITOR EQUIVALENT SERIES RESISTANCE (ESR)
The purely resistive component of a real capacitor’s imped-
ance (see
Figure 16). It causes power loss resulting in ca-
pacitor heating, which directly affects the capacitor’s operat-
ing lifetime. When used as a switching regulator output filter,
higher ESR values result in higher output ripple voltages.
DS011476-17
Note: Complete circuit not shown (see
Figure 10).
FIGURE 13. Undervoltage Lockout
for Buck-Boost Circuit
DS011476-18
Note: Complete circuit not shown.
FIGURE 14. Delayed Startup
DS011476-19
FIGURE 15. 1.2V to 55V Adjustable 3A Power Supply with Low Output Ripple
DS011476-20
FIGURE 16. Simple Model of a Real Capacitor
www.national.com
18
相关PDF资料
PDF描述
LNK304GTL 0.4 A SWITCHING REGULATOR, 70 kHz SWITCHING FREQ-MAX, PDSO8
LSN-2.5/10-D3BJ 1-OUTPUT 25 W DC-DC REG PWR SUPPLY MODULE
LSN-1.8/10-D3 1-OUTPUT DC-DC REG PWR SUPPLY MODULE
LS4601-9PD1TB1 1-OUTPUT 100 W AC-DC PWR FACTOR CORR MODULE
LS4601-9PD0T 1-OUTPUT 100 W AC-DC PWR FACTOR CORR MODULE
相关代理商/技术参数
参数描述
LM2576-5 制造商:MOTOROLA 制造商全称:Motorola, Inc 功能描述:Easy Switcher 3.0A Step-Down Voltage Regulator
LM2576-5.0 制造商:FCI 制造商全称:First Components International 功能描述:SMIPLE SWITCHER 3.0A Step-Down Voltage Regulator
LM2576-5.0BT 功能描述:IC REG BUCK 5V 3A TO220-5 RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:20 系列:SIMPLE SWITCHER® 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:12V 输入电压:4 V ~ 60 V PWM 型:电压模式 频率 - 开关:52kHz 电流 - 输出:1A 同步整流器:无 工作温度:-40°C ~ 125°C 安装类型:通孔 封装/外壳:16-DIP(0.300",7.62mm) 包装:管件 供应商设备封装:16-DIP 其它名称:*LM2575HVN-12LM2575HVN-12
LM2576-5.0BT⒂ 制造商:MICREL 制造商全称:Micrel Semiconductor 功能描述:52kHz Simple 3A Buck Voltage Regulator
LM2576-5.0BU 功能描述:IC REG BUCK 5V 3A TO263-5 RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:20 系列:SIMPLE SWITCHER® 类型:降压(降压) 输出类型:固定 输出数:1 输出电压:12V 输入电压:4 V ~ 60 V PWM 型:电压模式 频率 - 开关:52kHz 电流 - 输出:1A 同步整流器:无 工作温度:-40°C ~ 125°C 安装类型:通孔 封装/外壳:16-DIP(0.300",7.62mm) 包装:管件 供应商设备封装:16-DIP 其它名称:*LM2575HVN-12LM2575HVN-12