ZHCSIT8 September 2018 LM2734-Q1
PRODUCTION DATA.
- 1 特性
- 2 应用
- 3 说明
- 4 修订历史记录
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Detailed Description
-
8 Application and Implementation
- 8.1 Application Information
- 8.2
Typical Applications
- 8.2.1 LM2734X (1.6 MHz) VBOOST Derived from VIN 5V to 1.5 V/1 A
- 8.2.2 LM2734X (1.6 MHz) VBOOST Derived from VOUT 12 V to 3.3 V /1 A
- 8.2.3 LM2734X (1.6 MHz) VBOOST Derived from VSHUNT 18 V to 1.5 V /1 A
- 8.2.4 LM2734X (1.6 MHz) VBOOST Derived from Series Zener Diode (VIN) 15 V to 1.5 V / 1 A
- 8.2.5 LM2734X (1.6 MHz) VBOOST Derived from Series Zener Diode (VOUT) 15 V to 9 V /1 A
- 8.2.6 LM2734Y (550 kHz) VBOOST Derived from VIN 5 V to 1.5 V / 1 A
- 8.2.7 LM2734Y (550 kHz) VBOOST Derived from VOUT 12 V to 3.3 V / 1 A
- 8.2.8 LM2734Y (550 kHz) VBOOST Derived from VSHUNT 18 V to 1.5 V / 1 A
- 8.2.9 LM2734Y (550 kHz) VBOOST Derived from Series Zener Diode (VIN) 15 V to 1.5 V / 1 A
- 8.2.10 LM2734Y (550 kHz) VBOOST Derived from Series Zener Diode (VOUT) 15 V to 9 V / 1 A
- 9 Power Supply Recommendations
- 10Layout
- 11器件和文档支持
- 12机械、封装和可订购信息
8.2.1.2.4 Output Capacitor
The output capacitor is selected based upon the desired output ripple and transient response. The initial current of a load transient is provided mainly by the output capacitor. The output ripple of the converter is:
When using MLCCs, the ESR is typically so low that the capacitive ripple may dominate. When this occurs, the output ripple will be approximately sinusoidal and 90° phase shifted from the switching action. Given the availability and quality of MLCCs and the expected output voltage of designs using the LM2734-Q1 device, there is really no need to review any other capacitor technologies. Another benefit of ceramic capacitors is their ability to bypass high frequency noise. A certain amount of switching edge noise will couple through parasitic capacitances in the inductor to the output. A ceramic capacitor will bypass this noise while a tantalum will not. Because the output capacitor is one of the two external components that control the stability of the regulator control loop, most applications will require a minimum at 10 µF of output capacitance. Capacitance can be increased significantly with little detriment to the regulator stability. Like the input capacitor, recommended multilayer ceramic capacitors are X7R or X5R. Again, verify actual capacitance at the desired operating voltage and temperature.
Check the RMS current rating of the capacitor. The RMS current rating of the capacitor chosen must also meet the following condition:
