Datasheet LTC3417A-2 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | Dual Synchronous 1.5A/1A 4MHz Step-Down DC/DC Regulator |
| Seiten / Seite | 20 / 1 — FEATURES. DESCRIPTION. High Effi ciency: Up to 95%. 1.5A/1A Guaranteed … |
| Dateiformat / Größe | PDF / 345 Kb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTION. High Effi ciency: Up to 95%. 1.5A/1A Guaranteed Minimum Output Current. Synchronizable to External Clock
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LTC3417A-2 Dual Synchronous 1.5A/1A 4MHz Step-Down DC/DC Regulator
FEATURES DESCRIPTION
n
High Effi ciency: Up to 95%
The LTC®3417A-2 is a dual constant frequency, synchro- n
1.5A/1A Guaranteed Minimum Output Current
nous step-down DC/DC converter. Intended for medium n
Synchronizable to External Clock
power applications, it operates from a 2.25V to 5.5V input n
No Schottky Diodes Required
voltage range and has a constant programmable switching n
Programmable Frequency Operation: 1.5MHz or
frequency, allowing the use of tiny, low cost capacitors
Adjustable From 0.6MHz to 4MHz
and inductors 2mm or less in height. Each output voltage n
Low Ripple (<35mV
is adjustable from 0.8V to 5V. Internal synchronous, low
P-P) BurstMode
®
Operation I
R
Q: 125μA in Sleep
DS(ON) power switches provide high effi ciency without n
Low R
the need for external Schottky diodes.
DS(ON) Internal Switches
n Short-Circuit Protected A user selectable mode input allows the user to trade n VIN: 2.25V to 5.5V off ripple voltage for light load effi ciency. Burst Mode n Current Mode Operation for Excellent Line and Load operation provides high effi ciency at light loads, while Transient Response Pulse Skip mode provides low ripple noise at light loads. n Ultralow Shutdown Current: IQ < 1μA A phase mode pin allows the second channel to operate n Low Dropout Operation: 100% Duty Cycle in-phase or 180° out-of-phase with respect to channel 1. n Power Good Ouput Out-of-phase operation produces lower RMS current on n Phase Pin Selects 2nd Channel Phase Relationship VIN and thus lower stress on the input capacitor. with Respect to 1st Channel n Internal Soft-Start with Individual Run Pin Control To further maximize battery life, the P-channel MOSFETs n Available in Small Thermally Enhanced are turned on continuously in dropout (100% duty cycle) (5mm × 3mm) DFN and 20-Lead TSSOP Packages and both channels draw a total quiescent current of only 100μA. In shutdown, the device draws <1μA.
APPLICATIONS
L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. n GPS/Navigation Systems All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, 6144194. n Automotive Instrumentation n PC Cards n Industrial Power Supplies n General Purpose Point of Load DC/DC
VOUT2 Effi ciency TYPICAL APPLICATION (Burst Mode Operation)
VIN 100 10 REFER TO FIGURE 4 2.5V TO 5.5V 10μF VIN 95 EFFICIENCY 1 FREQ V 1.5μH 2.2μH POWER LOSS (W) OUT1 VOUT2 90 1.8V SW1 SW2 2.5V 22pF 22pF 1.5A 1A 0.1 VIN RUN1 RUN2 VIN 85 LTC3417A-2 511k 866k 0.01 V EFFICIENCY (%) FB1 VFB2 80 POWER LOSS 47μF 412k 412k 22μF 0.001 75 I V TH1 ITH2 IN = 3.6V VOUT = 2.5V 5.9k 2.87k GND FREQ = 1MHz 70 0.0001 2200pF 6800pF 0.001 0.01 0.1 1 LOAD CURRENT (A) 3417A-2 TA01 3417A-2 TA01a 3417a2fa 1
FEATURES DESCRIPTION
n
High Effi ciency: Up to 95%
The LTC®3417A-2 is a dual constant frequency, synchro- n
1.5A/1A Guaranteed Minimum Output Current
nous step-down DC/DC converter. Intended for medium n
Synchronizable to External Clock
power applications, it operates from a 2.25V to 5.5V input n
No Schottky Diodes Required
voltage range and has a constant programmable switching n
Programmable Frequency Operation: 1.5MHz or
frequency, allowing the use of tiny, low cost capacitors
Adjustable From 0.6MHz to 4MHz
and inductors 2mm or less in height. Each output voltage n
Low Ripple (<35mV
is adjustable from 0.8V to 5V. Internal synchronous, low
P-P) BurstMode
®
Operation I
R
Q: 125μA in Sleep
DS(ON) power switches provide high effi ciency without n
Low R
the need for external Schottky diodes.
DS(ON) Internal Switches
n Short-Circuit Protected A user selectable mode input allows the user to trade n VIN: 2.25V to 5.5V off ripple voltage for light load effi ciency. Burst Mode n Current Mode Operation for Excellent Line and Load operation provides high effi ciency at light loads, while Transient Response Pulse Skip mode provides low ripple noise at light loads. n Ultralow Shutdown Current: IQ < 1μA A phase mode pin allows the second channel to operate n Low Dropout Operation: 100% Duty Cycle in-phase or 180° out-of-phase with respect to channel 1. n Power Good Ouput Out-of-phase operation produces lower RMS current on n Phase Pin Selects 2nd Channel Phase Relationship VIN and thus lower stress on the input capacitor. with Respect to 1st Channel n Internal Soft-Start with Individual Run Pin Control To further maximize battery life, the P-channel MOSFETs n Available in Small Thermally Enhanced are turned on continuously in dropout (100% duty cycle) (5mm × 3mm) DFN and 20-Lead TSSOP Packages and both channels draw a total quiescent current of only 100μA. In shutdown, the device draws <1μA.
APPLICATIONS
L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. n GPS/Navigation Systems All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, 6144194. n Automotive Instrumentation n PC Cards n Industrial Power Supplies n General Purpose Point of Load DC/DC
VOUT2 Effi ciency TYPICAL APPLICATION (Burst Mode Operation)
VIN 100 10 REFER TO FIGURE 4 2.5V TO 5.5V 10μF VIN 95 EFFICIENCY 1 FREQ V 1.5μH 2.2μH POWER LOSS (W) OUT1 VOUT2 90 1.8V SW1 SW2 2.5V 22pF 22pF 1.5A 1A 0.1 VIN RUN1 RUN2 VIN 85 LTC3417A-2 511k 866k 0.01 V EFFICIENCY (%) FB1 VFB2 80 POWER LOSS 47μF 412k 412k 22μF 0.001 75 I V TH1 ITH2 IN = 3.6V VOUT = 2.5V 5.9k 2.87k GND FREQ = 1MHz 70 0.0001 2200pF 6800pF 0.001 0.01 0.1 1 LOAD CURRENT (A) 3417A-2 TA01 3417A-2 TA01a 3417a2fa 1