Datasheet LTC3025-1, LTC3025-2, LTC3025-3, LTC3025-4 (Analog Devices) - 9
| Fabricante | Analog Devices |
| Descripción | 500mA Micropower VLDO Linear Regulators |
| Páginas / Página | 14 / 9 — applicaTions inForMaTion. Output Capacitance and Transient Response. … |
| Formato / tamaño de archivo | PDF / 256 Kb |
| Idioma del documento | Inglés |
applicaTions inForMaTion. Output Capacitance and Transient Response. Figure 3. Ceramic Capacitor DC Bias Characteristics
Línea de modelo para esta hoja de datos
- LTC3025EDC-1#PBF LTC3025EDC-1#TRMPBF LTC3025EDC-1#TRMPBF LTC3025EDC-1#TRPBF LTC3025EDC-1#TRPBF LTC3025EDC-2#TRMPBF LTC3025EDC-2#TRPBF LTC3025EDC-3#TRMPBF LTC3025EDC-3#TRPBF LTC3025EDC-4#TRMPBF LTC3025EDC-4#TRPBF LTC3025IDC-1#PBF LTC3025IDC-1#TRMPBF LTC3025IDC-1#TRMPBF LTC3025IDC-1#TRPBF LTC3025IDC-1#TRPBF LTC3025IDC-2#TRMPBF LTC3025IDC-2#TRPBF LTC3025IDC-3#TRMPBF LTC3025IDC-3#TRPBF LTC3025IDC-4#TRMPBF LTC3025IDC-4#TRPBF
- LTC3025EDC-2#PBF LTC3025EDC-2#TRMPBF LTC3025EDC-2#TRPBF LTC3025IDC-2#PBF LTC3025IDC-2#TRMPBF LTC3025IDC-2#TRPBF
Versión de texto del documento
LTC3025-1/LTC3025-2/ LTC3025-3/LTC3025-4
applicaTions inForMaTion Output Capacitance and Transient Response
20 BOTH CAPACITORS ARE 1µF, The LTC3025-X is designed to be stable with a wide range 10V, 0603 CASE SIZE 0 of ceramic output capacitors. The ESR of the output capaci- X5R tor affects stability, most notably with small capacitors. A –20 minimum output capacitor of 1µF with an ESR of 0.05Ω or ALUE (%) –40 less is recommended to ensure stability. The LTC3025-X is Y5V a micropower device and output transient response will be –60 CHANGE IN V a function of output capacitance. Larger values of output capacitance decrease the peak deviations and provide im- –80 proved transient response for larger load current changes. –100 0 Note that bypass capacitors used to decouple individual 2 4 6 8 10 DC BIAS VOLTAGE (V) components powered by the LTC3025-X will increase the 30251234 F03 effective output capacitor value. High ESR tantalum and
Figure 3. Ceramic Capacitor DC Bias Characteristics
electrolytic capacitors may be used, but a low ESR ceramic capacitor must be in parallel at the output. There is no 20 minimum ESR or maximum capacitor size requirements. 0 Extra consideration must be given to the use of ceramic X5R capacitors. Ceramic capacitors are manufactured with a –20 Y5V variety of dielectrics, each with different behavior across –40 temperature and applied voltage. The most common di- electrics used are Z5U, Y5V, X5R and X7R. The Z5U and –60 Y5V dielectrics are good for providing high capacitances CHANGE IN VALUE (%) in a small package, but exhibit large voltage and tem- –80 BOTH CAPACITORS ARE 1µF, perature coefficients as shown in Figures 3 and 4. When 10V, 0603 CASE SIZE –100 used with a 2V regulator, a 1µF Y5V capacitor can lose as –50 –25 0 25 50 75 TEMPERATURE (°C) much as 75% of its initial capacitance over the operating 30251234 F04 temperature range. The X5R and X7R dielectrics result in
Figure 4. Ceramic Capacitor Temperature Characteristics
more stable characteristics and are usually more suitable for use as the output capacitor. The X7R type has better stability across temperature, while the X5R is less expensive and is available in higher values. In all cases, the output capacitance should never drop below 0.4µF, or instability or degraded performance may occur. 30251234ff 9 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Package Description Revision History Typical Application Related Parts
applicaTions inForMaTion Output Capacitance and Transient Response
20 BOTH CAPACITORS ARE 1µF, The LTC3025-X is designed to be stable with a wide range 10V, 0603 CASE SIZE 0 of ceramic output capacitors. The ESR of the output capaci- X5R tor affects stability, most notably with small capacitors. A –20 minimum output capacitor of 1µF with an ESR of 0.05Ω or ALUE (%) –40 less is recommended to ensure stability. The LTC3025-X is Y5V a micropower device and output transient response will be –60 CHANGE IN V a function of output capacitance. Larger values of output capacitance decrease the peak deviations and provide im- –80 proved transient response for larger load current changes. –100 0 Note that bypass capacitors used to decouple individual 2 4 6 8 10 DC BIAS VOLTAGE (V) components powered by the LTC3025-X will increase the 30251234 F03 effective output capacitor value. High ESR tantalum and
Figure 3. Ceramic Capacitor DC Bias Characteristics
electrolytic capacitors may be used, but a low ESR ceramic capacitor must be in parallel at the output. There is no 20 minimum ESR or maximum capacitor size requirements. 0 Extra consideration must be given to the use of ceramic X5R capacitors. Ceramic capacitors are manufactured with a –20 Y5V variety of dielectrics, each with different behavior across –40 temperature and applied voltage. The most common di- electrics used are Z5U, Y5V, X5R and X7R. The Z5U and –60 Y5V dielectrics are good for providing high capacitances CHANGE IN VALUE (%) in a small package, but exhibit large voltage and tem- –80 BOTH CAPACITORS ARE 1µF, perature coefficients as shown in Figures 3 and 4. When 10V, 0603 CASE SIZE –100 used with a 2V regulator, a 1µF Y5V capacitor can lose as –50 –25 0 25 50 75 TEMPERATURE (°C) much as 75% of its initial capacitance over the operating 30251234 F04 temperature range. The X5R and X7R dielectrics result in
Figure 4. Ceramic Capacitor Temperature Characteristics
more stable characteristics and are usually more suitable for use as the output capacitor. The X7R type has better stability across temperature, while the X5R is less expensive and is available in higher values. In all cases, the output capacitance should never drop below 0.4µF, or instability or degraded performance may occur. 30251234ff 9 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Package Description Revision History Typical Application Related Parts