ZHCS535M February 2013 – October 2020 LM22679 , LM22679-Q1
PRODUCTION DATA
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Detailed Description
- 8 Application and Implementation
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
8.2.1.2.4 Output Capacitor
The output capacitor is responsible for filtering the output voltage and supplying load current during transients. Capacitor selection depends on application conditions as well as ripple and transient requirements. Best performance is achieved with a parallel combination of ceramic capacitors and a low ESR SP? or POSCAP? types. Very low ESR capacitors such as ceramics reduce the output ripple and noise spikes, while higher value electrolytics or polymers provide large bulk capacitance to supply transients. Assuming very low ESR, Equation 15 gives an approximation to the output voltage ripple:
Typically, a total value of 100 μF or greater is recommended for output capacitance.
In applications with Vout less than 3.3 V, it is critical that low ESR output capacitors are selected. This will limit potential output voltage overshoots as the input voltage falls below the device normal operating range.