Datasheet LTC3560 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | 2.25MHz, 800mA Synchronous Step-Down Regulator in ThinSOT |
| Seiten / Seite | 16 / 1 — FEATURES. DESCRIPTION. High Effi ciency: Up to 95%. Low Output Ripple … |
| Dateiformat / Größe | PDF / 267 Kb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTION. High Effi ciency: Up to 95%. Low Output Ripple (<20mVP-P): Burst Mode. Operation: IQ = 16μA
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LTC3560 2.25MHz, 800mA Synchronous Step-Down Regulator in ThinSOT
FEATURES DESCRIPTION
n
High Effi ciency: Up to 95%
The LTC®3560 is a high effi ciency monolithic synchronous n
Low Output Ripple (<20mVP-P): Burst Mode
® buck regulator using a constant frequency, current mode
Operation: IQ = 16μA
architecture. Supply current during operation is only 16μA, n
2.5V to 5.5V Input Voltage Range
dropping to <1μA in shutdown. The 2.5V to 5.5V input n
2.25MHz Constant Frequency Operation
voltage range makes the LTC3560 ideally suited for single n Synchronizable to External Clock Li-Ion/Li-Polymer battery-powered applications. 100% n No Schottky Diode Required duty cycle provides low dropout operation, extending n Stable with Ceramic Capacitors battery life in portable systems. n Low Dropout Operation: 100% Duty Cycle Switching frequency is internally set at 2.25MHz, allowing n 0.6V Reference Allows Low Output Voltages the use of small surface mount inductors and capacitors. n Shutdown Mode Draws < 1μA Supply Current For noise sensitive applications the LTC3560 can be ex- n ±2% Output Voltage Accuracy ternally synchronized from 1MHz to 3MHz. Burst Mode n Current Mode Operation for Excellent Line and operation is inhibited during synchronization or when the Load Transient Response SYNC/MODE pin is pulled high, preventing low frequency n Overtemperature Protected ripple from interfering with audio circuitry. n Low Profi le (1mm) ThinSOT™ Package The internal synchronous switch increases effi ciency and eliminates the need for an external Schottky diode.
APPLICATIONS
Low output voltages are easily supported with the 0.6V n feedback reference voltage. The LTC3560 is available in a Cellular Telephones n low profi le (1mm) ThinSOT package. Wireless and DSL Modems n Digital Still Cameras L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property n Media Players of their respective owners. Protected by U.S. Patents including 6580258, 5481178, 5994885, 6304066, 6498466, 6611131. n Portable Instruments
TYPICAL APPLICATION
100 1 90 80 0.1 70 POWER LOSS (W) 60 V 2.2μH IN V 2.7V V OUT 50 0.01 IN SW 2.5V TO 5.5V C 10pF IN C 40 10μF LTC3560 OUT 10μF EFFICIENCY (%) CER RUN CER 30 0.001 SYNC/MODE VFB 20 VIN = 3.6V 806k GND 10 VIN = 4.2V 255k VIN = 5.5V 3405A F01a 0 0.0001 0.1 1 10 100 1000 LOAD CURRENT (mA) 3560 F01b
Figure 1a. High Effi ciency Step-Down Converter Figure 1b. Effi ciency vs Load Current
3560fb 1
FEATURES DESCRIPTION
n
High Effi ciency: Up to 95%
The LTC®3560 is a high effi ciency monolithic synchronous n
Low Output Ripple (<20mVP-P): Burst Mode
® buck regulator using a constant frequency, current mode
Operation: IQ = 16μA
architecture. Supply current during operation is only 16μA, n
2.5V to 5.5V Input Voltage Range
dropping to <1μA in shutdown. The 2.5V to 5.5V input n
2.25MHz Constant Frequency Operation
voltage range makes the LTC3560 ideally suited for single n Synchronizable to External Clock Li-Ion/Li-Polymer battery-powered applications. 100% n No Schottky Diode Required duty cycle provides low dropout operation, extending n Stable with Ceramic Capacitors battery life in portable systems. n Low Dropout Operation: 100% Duty Cycle Switching frequency is internally set at 2.25MHz, allowing n 0.6V Reference Allows Low Output Voltages the use of small surface mount inductors and capacitors. n Shutdown Mode Draws < 1μA Supply Current For noise sensitive applications the LTC3560 can be ex- n ±2% Output Voltage Accuracy ternally synchronized from 1MHz to 3MHz. Burst Mode n Current Mode Operation for Excellent Line and operation is inhibited during synchronization or when the Load Transient Response SYNC/MODE pin is pulled high, preventing low frequency n Overtemperature Protected ripple from interfering with audio circuitry. n Low Profi le (1mm) ThinSOT™ Package The internal synchronous switch increases effi ciency and eliminates the need for an external Schottky diode.
APPLICATIONS
Low output voltages are easily supported with the 0.6V n feedback reference voltage. The LTC3560 is available in a Cellular Telephones n low profi le (1mm) ThinSOT package. Wireless and DSL Modems n Digital Still Cameras L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property n Media Players of their respective owners. Protected by U.S. Patents including 6580258, 5481178, 5994885, 6304066, 6498466, 6611131. n Portable Instruments
TYPICAL APPLICATION
100 1 90 80 0.1 70 POWER LOSS (W) 60 V 2.2μH IN V 2.7V V OUT 50 0.01 IN SW 2.5V TO 5.5V C 10pF IN C 40 10μF LTC3560 OUT 10μF EFFICIENCY (%) CER RUN CER 30 0.001 SYNC/MODE VFB 20 VIN = 3.6V 806k GND 10 VIN = 4.2V 255k VIN = 5.5V 3405A F01a 0 0.0001 0.1 1 10 100 1000 LOAD CURRENT (mA) 3560 F01b
Figure 1a. High Effi ciency Step-Down Converter Figure 1b. Effi ciency vs Load Current
3560fb 1