参数资料
型号: LM2594-ADJMWC
厂商: NATIONAL SEMICONDUCTOR CORP
元件分类: 稳压器
英文描述: 1.4 A SWITCHING REGULATOR, 173 kHz SWITCHING FREQ-MAX, UUC
封装: WAFER
文件页数: 5/33页
文件大小: 837K
代理商: LM2594-ADJMWC
LM2594/LM2594HV Series Buck Regulator Design Procedure (Adjustable
Output) (Continued)
PROCEDURE (Adjustable Output Voltage Version)
EXAMPLE (Adjustable Output Voltage Version)
4. Feedforward Capacitor (C
FF) (See Figure 1 )
For output voltages greater than approximately 10V, an addi-
tional capacitor is required. The compensation capacitor is
typically between 50 pF and 10 nF, and is wired in parallel
with the output voltage setting resistor, R
2. It provides addi-
tional stability for high output voltages, low input-output volt-
ages, and/or very low ESR output capacitors, such as solid
tantalum capacitors.
This capacitor type can be ceramic, plastic, silver mica, etc.
(Because of the unstable characteristics of ceramic capaci-
tors made with Z5U material, they are not recommended.)
4. Feedforward Capacitor (C
FF)
The table shown in
Figure 3 contains feed forward capacitor
values for various output voltages. In this example,a1nF
capacitor is needed.
5. Catch Diode Selection (D1)
A. The catch diode current rating must be at least 1.3 times
greater than the maximum load current. Also, if the power
supply design must withstand a continuous output short, the
diode should have a current rating equal to the maximum
current limit of the LM2594. The most stressful condition for
this diode is an overload or shorted output condition.
B. The reverse voltage rating of the diode should be at least
1.25 times the maximum input voltage.
C. This diode must be fast (short reverse recovery time) and
must be located close to the LM2594 using short leads and
short printed circuit traces. Because of their fast switching
speed and low forward voltage drop, Schottky diodes provide
the best performance and efficiency, and should be the first
choice, especially in low output voltage applications.
Ultra-fast recovery, or High-Efficiency rectifiers are also a
good choice, but some types with an abrupt turn-off charac-
teristic may cause instability or EMl problems. Ultra-fast re-
covery diodes typically have reverse recovery times of 50 ns
or less. Rectifiers such as the 1N4001 series are much too
slow and should not be used.
5. Catch Diode Selection (D1)
A. Refer to the table shown in
Figure 11. Schottky diodes
provide the best performance, and in this example a 1A, 40V,
1N5819 Schottky diode would be a good choice. The 1A di-
ode rating is more than adequate and will not be over-
stressed even for a shorted output.
LM2594/LM2594HV
www.national.com
13
相关PDF资料
PDF描述
LM2594HV-12MWC 1.4 A SWITCHING REGULATOR, 173 kHz SWITCHING FREQ-MAX, UUC
LM2594HV-12MDC 1.4 A SWITCHING REGULATOR, 173 kHz SWITCHING FREQ-MAX, UUC
LM2594-3.3MDC 1.4 A SWITCHING REGULATOR, 173 kHz SWITCHING FREQ-MAX, UUC
LM2595J-12-QML 2.6 A SWITCHING REGULATOR, 173 kHz SWITCHING FREQ-MAX, CDIP16
5962-9687901QEA 2.6 A SWITCHING REGULATOR, 173 kHz SWITCHING FREQ-MAX, CDIP16
相关代理商/技术参数
参数描述
LM2594APDBCKGEVB 功能描述:电源管理IC开发工具 LM2594ADJ PDIP8 BUCK DB RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
LM2594ASCBCKGEVB 功能描述:BOARD EVAL FOR LM2594ADJ 8-SOIC RoHS:是 类别:编程器,开发系统 >> 评估板 - DC/DC 与 AC/DC(离线)SMPS 系列:* 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:True Shutdown™ 主要目的:DC/DC,步升 输出及类型:1,非隔离 功率 - 输出:- 输出电压:- 电流 - 输出:1A 输入电压:2.5 V ~ 5.5 V 稳压器拓扑结构:升压 频率 - 开关:3MHz 板类型:完全填充 已供物品:板 已用 IC / 零件:MAX8969
LM2594DADJG 功能描述:直流/直流开关调节器 0.5A BUCK SW REG 150KHZ RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
LM2594DADJR2G 功能描述:直流/直流开关调节器 0.5A BUCK SW REG 150KHZ RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
LM2594HVM-12 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT