Datasheet LTC1258 (Analog Devices) - 6
| Fabricante | Analog Devices |
| Descripción | Micropower Low Dropout References |
| Páginas / Página | 8 / 6 — BLOCK DIAGRAM. APPLICATIONS INFORMATION Longer Battery Life. Output … |
| Formato / tamaño de archivo | PDF / 137 Kb |
| Idioma del documento | Inglés |
BLOCK DIAGRAM. APPLICATIONS INFORMATION Longer Battery Life. Output Bypass Capacitor
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- LTC1258CMS8-2.5#PBF LTC1258CMS8-2.5#PBF LTC1258CMS8-2.5#TRPBF LTC1258CMS8-2.5#TRPBF LTC1258CMS8-3#PBF LTC1258CMS8-3#PBF LTC1258CMS8-3#TRPBF LTC1258CMS8-3#TRPBF LTC1258CMS8-4.1#PBF LTC1258CMS8-4.1#PBF LTC1258CMS8-4.1#TRPBF LTC1258CMS8-4.1#TRPBF LTC1258CMS8-5#PBF LTC1258CMS8-5#PBF LTC1258CMS8-5#TRPBF LTC1258CMS8-5#TRPBF LTC1258CS8-2.5#PBF LTC1258CS8-2.5#PBF LTC1258CS8-2.5#TRPBF LTC1258CS8-2.5#TRPBF LTC1258CS8-3#PBF LTC1258CS8-3#PBF LTC1258CS8-3#TRPBF LTC1258CS8-3#TRPBF LTC1258CS8-4.1#PBF LTC1258CS8-4.1#PBF LTC1258CS8-4.1#TRPBF LTC1258CS8-4.1#TRPBF LTC1258CS8-5#PBF LTC1258CS8-5#PBF LTC1258CS8-5#TRPBF LTC1258CS8-5#TRPBF
Versión de texto del documento
LTC1258 Series
BLOCK DIAGRAM
2 IN + OUT 1 – 2.385V R1 FB 3 (LTC1258) R2 GND 4 1258 BD NOTE: R1 AND R2 ARE NOT CONNECTED FOR LTC1258
APPLICATIONS INFORMATION Longer Battery Life Output Bypass Capacitor
Series references have an advantage over shunt style The LTC1258 series is designed to be stable with or without references. To operate, shunt references require a resistor capacitive loads. With no capacitive load, the reference between the power supply and the output. This resistor is ideal for fast settling applications, or where PC board must be chosen to supply the maximum current that is space is at a premium. demanded by the circuit being regulated. When the circuit In applications with signifi cant output loading changes, being controlled is not operating at this maximum current, an output bypass capacitor of up to 1μF can be used to the shunt reference must always sink this current, resulting improve the output transient response. Figure 1 shows in high power dissipation and short battery life. the response of the reference to a 1mA to 0μA load step The LTC1258 series low dropout references do not require with a 1μF output capacitor. If more than 1μF of output a current setting resistor and can operate with any supply capacitance is required, a resistor in series with the capaci- voltage from (VOUT(NOMINAL) + 0.2V) to 12.6V. When the tor is recommended to reduce the output ringing. Figure 2 circuitry being regulated does not demand current, the illustrates the use of a damping resistor for capacitive loads LTC1258 series reduces its dissipation and battery life is greater than 1μF. Figure 3 shows the resistor and capacitor extended. If the reference is not delivering load current it values required to achieve critical damping. dissipates only 10.8μW when operating on a 2.7V supply for LTC1258-2.5, yet the same connection can deliver 10mA of load current when demanded. 1mA 1mA IOUT IOUT 0mA 0mA VOUT VOUT 100mV/DIV 100mV/DIV 10ms/DIV 1258 F01a 0.5ms/DIV 1258 F01b
Figure 1. Reference Output Load Transient Response, 1μF Output Capacitor
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BLOCK DIAGRAM
2 IN + OUT 1 – 2.385V R1 FB 3 (LTC1258) R2 GND 4 1258 BD NOTE: R1 AND R2 ARE NOT CONNECTED FOR LTC1258
APPLICATIONS INFORMATION Longer Battery Life Output Bypass Capacitor
Series references have an advantage over shunt style The LTC1258 series is designed to be stable with or without references. To operate, shunt references require a resistor capacitive loads. With no capacitive load, the reference between the power supply and the output. This resistor is ideal for fast settling applications, or where PC board must be chosen to supply the maximum current that is space is at a premium. demanded by the circuit being regulated. When the circuit In applications with signifi cant output loading changes, being controlled is not operating at this maximum current, an output bypass capacitor of up to 1μF can be used to the shunt reference must always sink this current, resulting improve the output transient response. Figure 1 shows in high power dissipation and short battery life. the response of the reference to a 1mA to 0μA load step The LTC1258 series low dropout references do not require with a 1μF output capacitor. If more than 1μF of output a current setting resistor and can operate with any supply capacitance is required, a resistor in series with the capaci- voltage from (VOUT(NOMINAL) + 0.2V) to 12.6V. When the tor is recommended to reduce the output ringing. Figure 2 circuitry being regulated does not demand current, the illustrates the use of a damping resistor for capacitive loads LTC1258 series reduces its dissipation and battery life is greater than 1μF. Figure 3 shows the resistor and capacitor extended. If the reference is not delivering load current it values required to achieve critical damping. dissipates only 10.8μW when operating on a 2.7V supply for LTC1258-2.5, yet the same connection can deliver 10mA of load current when demanded. 1mA 1mA IOUT IOUT 0mA 0mA VOUT VOUT 100mV/DIV 100mV/DIV 10ms/DIV 1258 F01a 0.5ms/DIV 1258 F01b
Figure 1. Reference Output Load Transient Response, 1μF Output Capacitor
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