Datasheet LT1956, LT1956-5 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | High Voltage, 1.5A, 500kHz Step-Down Switching Regulators |
| Seiten / Seite | 28 / 1 — FEATURES. DESCRIPTIO. Wide Input Range: 5.5V to 60V. 1.5A Peak Switch … |
| Dateiformat / Größe | PDF / 316 Kb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTIO. Wide Input Range: 5.5V to 60V. 1.5A Peak Switch Current. Small 16-Pin SSOP or Thermally Enhanced
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LT1956/LT1956-5 High Voltage, 1.5A, 500kHz Step-Down Switching Regulators
U FEATURES DESCRIPTIO
■
Wide Input Range: 5.5V to 60V
The LT ®1956/LT1956-5 are 500kHz monolithic buck ■
1.5A Peak Switch Current
switching regulators with an input voltage capability up to ■
Small 16-Pin SSOP or Thermally Enhanced
60V. A high efficiency 1.5A, 0.2Ω switch is included on the
TSSOP Package
die along with all the necessary oscillator, control and logic ■
Saturating Switch Design: 0.2
Ω circuitry. A current mode architecture provides fast tran- ■
Peak Switch Current Maintained Over
sient response and good loop stability.
Full Duty Cycle Range
Special design techniques and a new high voltage process ■
Constant 500kHz Switching Frequency
achieve high efficiency over a wide input range. Efficiency ■ Effective Supply Current: 2.5mA is maintained over a wide output current range by using the ■ Shutdown Current: 25µA output to bias the circuitry and by utilizing a supply boost ■ 1.2V Feedback Reference (LT1956) capacitor to saturate the power switch. Patented circuitry ■ 5V Fixed Output (LT1956-5) maintains peak switch current over the full duty cycle ■ Easily Synchronizable range*. A shutdown pin reduces supply current to 25µA and ■ Cycle-by-Cycle Current Limiting the device can be externally synchronized from 580kHz to
U
700kHz with a logic level input.
APPLICATIO S
The LT1956/LT1956-5 are available in fused-lead 16-pin ■ High Voltage, Industrial and Automotive SSOP and thermally enhanced TSSOP packages. ■ Portable Computers , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Battery-Powered Systems *U.S. PATENT NO. 6,498,466 ■ Battery Chargers ■ Distributed Power Systems
U TYPICAL APPLICATIO 5V Buck Converter Efficiency vs Load Current
MMSD914TI 100 VIN = 12V 6 L = 18µH 0.1µF VOUT = 5V VIN BOOST 10µH 90 12V 4 2 VOUT VIN SW 5V (TRANSIENTS V 2.2µF† OUT = 3.3V TO 60V) 10MQ060N 1A 100V LT1956-5 80 22µF CERAMIC 6.3V 15 10 SHDN BIAS CERAMIC 70 EFFICIENCY (%) 14 12 SYNC FB 60 GND VC 1, 8, 9, 16 11 50 220pF 0 0.25 0.50 0.75 1.00 1.25 4.7k LOAD CURRENT (A) 1956 TA02 4700pF †UNITED CHEMI-CON THCS50EZA225ZT 1956 TA01 1956f 1
U FEATURES DESCRIPTIO
■
Wide Input Range: 5.5V to 60V
The LT ®1956/LT1956-5 are 500kHz monolithic buck ■
1.5A Peak Switch Current
switching regulators with an input voltage capability up to ■
Small 16-Pin SSOP or Thermally Enhanced
60V. A high efficiency 1.5A, 0.2Ω switch is included on the
TSSOP Package
die along with all the necessary oscillator, control and logic ■
Saturating Switch Design: 0.2
Ω circuitry. A current mode architecture provides fast tran- ■
Peak Switch Current Maintained Over
sient response and good loop stability.
Full Duty Cycle Range
Special design techniques and a new high voltage process ■
Constant 500kHz Switching Frequency
achieve high efficiency over a wide input range. Efficiency ■ Effective Supply Current: 2.5mA is maintained over a wide output current range by using the ■ Shutdown Current: 25µA output to bias the circuitry and by utilizing a supply boost ■ 1.2V Feedback Reference (LT1956) capacitor to saturate the power switch. Patented circuitry ■ 5V Fixed Output (LT1956-5) maintains peak switch current over the full duty cycle ■ Easily Synchronizable range*. A shutdown pin reduces supply current to 25µA and ■ Cycle-by-Cycle Current Limiting the device can be externally synchronized from 580kHz to
U
700kHz with a logic level input.
APPLICATIO S
The LT1956/LT1956-5 are available in fused-lead 16-pin ■ High Voltage, Industrial and Automotive SSOP and thermally enhanced TSSOP packages. ■ Portable Computers , LTC and LT are registered trademarks of Linear Technology Corporation. ■ Battery-Powered Systems *U.S. PATENT NO. 6,498,466 ■ Battery Chargers ■ Distributed Power Systems
U TYPICAL APPLICATIO 5V Buck Converter Efficiency vs Load Current
MMSD914TI 100 VIN = 12V 6 L = 18µH 0.1µF VOUT = 5V VIN BOOST 10µH 90 12V 4 2 VOUT VIN SW 5V (TRANSIENTS V 2.2µF† OUT = 3.3V TO 60V) 10MQ060N 1A 100V LT1956-5 80 22µF CERAMIC 6.3V 15 10 SHDN BIAS CERAMIC 70 EFFICIENCY (%) 14 12 SYNC FB 60 GND VC 1, 8, 9, 16 11 50 220pF 0 0.25 0.50 0.75 1.00 1.25 4.7k LOAD CURRENT (A) 1956 TA02 4700pF †UNITED CHEMI-CON THCS50EZA225ZT 1956 TA01 1956f 1