Datasheet LTC3407A (Analog Devices)
| Fabricante | Analog Devices |
| Descripción | Dual Synchronous 600mA, 1.5MHz Step-Down DC/DC Regulator |
| Páginas / Página | 16 / 1 — FEATURES. DESCRIPTION. High Effi ciency: Up to 96%. Low Ripple (35mVP-P) … |
| Formato / tamaño de archivo | PDF / 296 Kb |
| Idioma del documento | Inglés |
FEATURES. DESCRIPTION. High Effi ciency: Up to 96%. Low Ripple (35mVP-P) Burst Mode Operation;. IQ = 40μA
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LTC3407A Dual Synchronous 600mA, 1.5MHz Step-Down DC/DC Regulator
FEATURES DESCRIPTION
n
High Effi ciency: Up to 96%
The LTC®3407A is a dual, constant frequency, synchronous n
Low Ripple (35mVP-P) Burst Mode Operation;
step-down DC/DC converter. Intended for low power ap-
IQ = 40μA
plications, it operates from a 2.5V to 5.5V input voltage n
1.5MHz Constant Frequency Operation
range and has a constant 1.5MHz switching frequency, n
No Schottky Diodes Required
enabling the use of tiny, low cost capacitors and inductors n
Low RDS(ON) Internal Switches: 0.35
Ω 1mm or less in height. Each output voltage is adjustable n Current Mode Operation for Excellent Line from 0.6V to 5V. Internal synchronous 0.35Ω, 1A power and Load Transient Response switches provide high effi ciency without the need for n Short-Circuit Protected external Schottky diodes. n Low Dropout Operation: 100% Duty Cycle A user selectable mode input is provided to allow the user n Ultralow Shutdown Current: IQ < 1μA to trade-off ripple noise for low power effi ciency. Burst n Output Voltages from 5V down to 0.6V Mode® operation provides the highest effi ciency at light n Power-On Reset Output loads, while Pulse Skip Mode provides the lowest ripple n Externally Synchronizable Oscillator noise at light loads. n Optional External Soft-Start n Small Thermally Enhanced MSOP and 3mm To further maximize battery life, the P-channel MOSFETs × 3mm DFN Packages are turned on continuously in dropout (100% duty cycle), and both channels draw a total quiescent current of only
APPLICATIONS
40μA. In shutdown, the device draws <1μA. L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. n All other trademarks are the property of their respective owners. Protected by U.S. Patents PDAs/Palmtop PCs including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131. n Digital Cameras n Cellular Phones n Wireless and DSL Modems
TYPICAL APPLICATION 1mm High 2.5V/1.8V at 600mA Step-Down Regulators LTC3407A Effi ciency/Power Loss Curve
100 1 VIN = 2.5V 2.5V TO 5.5V 90 1.8V 10μF 100k 80 RUN/SS2 VIN RUN/SS1 0.1 POWER LOSS (W) 70 MODE/SYNC POR RESET 60 LTC3407A 50 0.01 2.2μH 2.2μH VOUT2 = 2.5V VOUT1 = 1.8V 40 SW2 SW1 AT 600mA AT 600mA EFFICIENCY (%) 22pF 22pF 30 0.001 20 VIN = 3.3V Burst Mode OPERATION V V FB2 FB1 10 887k 887k NO LOAD ON OTHER CHANNEL GND 280k 442k 0 0.0001 10μF 10μF 1 10 100 1000 LOAD CURRENT (mA) 3407A TA02 3407A TA01 3407afa 1
FEATURES DESCRIPTION
n
High Effi ciency: Up to 96%
The LTC®3407A is a dual, constant frequency, synchronous n
Low Ripple (35mVP-P) Burst Mode Operation;
step-down DC/DC converter. Intended for low power ap-
IQ = 40μA
plications, it operates from a 2.5V to 5.5V input voltage n
1.5MHz Constant Frequency Operation
range and has a constant 1.5MHz switching frequency, n
No Schottky Diodes Required
enabling the use of tiny, low cost capacitors and inductors n
Low RDS(ON) Internal Switches: 0.35
Ω 1mm or less in height. Each output voltage is adjustable n Current Mode Operation for Excellent Line from 0.6V to 5V. Internal synchronous 0.35Ω, 1A power and Load Transient Response switches provide high effi ciency without the need for n Short-Circuit Protected external Schottky diodes. n Low Dropout Operation: 100% Duty Cycle A user selectable mode input is provided to allow the user n Ultralow Shutdown Current: IQ < 1μA to trade-off ripple noise for low power effi ciency. Burst n Output Voltages from 5V down to 0.6V Mode® operation provides the highest effi ciency at light n Power-On Reset Output loads, while Pulse Skip Mode provides the lowest ripple n Externally Synchronizable Oscillator noise at light loads. n Optional External Soft-Start n Small Thermally Enhanced MSOP and 3mm To further maximize battery life, the P-channel MOSFETs × 3mm DFN Packages are turned on continuously in dropout (100% duty cycle), and both channels draw a total quiescent current of only
APPLICATIONS
40μA. In shutdown, the device draws <1μA. L, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. n All other trademarks are the property of their respective owners. Protected by U.S. Patents PDAs/Palmtop PCs including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131. n Digital Cameras n Cellular Phones n Wireless and DSL Modems
TYPICAL APPLICATION 1mm High 2.5V/1.8V at 600mA Step-Down Regulators LTC3407A Effi ciency/Power Loss Curve
100 1 VIN = 2.5V 2.5V TO 5.5V 90 1.8V 10μF 100k 80 RUN/SS2 VIN RUN/SS1 0.1 POWER LOSS (W) 70 MODE/SYNC POR RESET 60 LTC3407A 50 0.01 2.2μH 2.2μH VOUT2 = 2.5V VOUT1 = 1.8V 40 SW2 SW1 AT 600mA AT 600mA EFFICIENCY (%) 22pF 22pF 30 0.001 20 VIN = 3.3V Burst Mode OPERATION V V FB2 FB1 10 887k 887k NO LOAD ON OTHER CHANNEL GND 280k 442k 0 0.0001 10μF 10μF 1 10 100 1000 LOAD CURRENT (mA) 3407A TA02 3407A TA01 3407afa 1