Datasheet LTC3407-4 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Dual Synchronous, 800mA, 2.25MHz Step-Down DC/DC Regulator |
| Pages / Page | 16 / 1 — FEATURES. DESCRIPTION. High Effi ciency: Up to 95%. Very Low Quiescent … |
| File Format / Size | PDF / 275 Kb |
| Document Language | English |
FEATURES. DESCRIPTION. High Effi ciency: Up to 95%. Very Low Quiescent Current: Only 40μA. 2.25MHz Constant Frequency Operation
Model Line for this Datasheet
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LTC3407-4 Dual Synchronous, 800mA, 2.25MHz Step-Down DC/DC Regulator
FEATURES DESCRIPTION
n
High Effi ciency: Up to 95%
The LTC®3407-4 is a dual, constant frequency, synchro- n
Very Low Quiescent Current: Only 40μA
nous step down DC/DC converter. Intended for low power n
2.25MHz Constant Frequency Operation
applications, it operates from 2.5V to 5.5V input voltage n
High Switch Current: 1.2A on Each Channel
range and has a constant 2.25MHz switching frequency, n
No Schottky Diodes Required
allowing the use of tiny, low cost capacitors and induc- n
Low RDS(ON) Internal Switches: 0.35
Ω tors with a profi le ≤1mm. Each output voltage is adjust- n Current Mode Operation for Excellent Line able from 0.6V to 5V. Internal synchronous 0.35Ω, 1.2A and Load Transient Response power switches provide high effi ciency without the need n Short-Circuit Protected for 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 noise ripple for low power effi ciency. Burst n Output Voltages from 5V down to 0.6V Mode® operation provides high effi ciency at light loads, n Power-On Reset Output while pulse-skipping mode provides low noise ripple at n Externally Synchronizable Oscillator light loads. n Small Thermally Enhanced MSOP and 3mm × 3mm DFN Packages To further maximize battery life, the P-channel MOSFETs are turned on continuously in dropout (100% duty cycle),
APPLICATIONS
and both channels draw a total quiescent current of only 40μA. In shutdown, the device draws <1μA. n PDAs/Palmtop PCs n Digital Cameras The LTC3407-4 is identical to the LTC3407-2 except for n Cellular Phones the reduced power-on reset delay time. n Portable Media Players L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks n PC Cards of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815, 6498466, n Wireless and DSL Modems 6611131.
TYPICAL APPLICATION LTC3407-4 Effi ciency/Power Loss Curve
VIN* 2.5V TO 5.5V R5 100 1 C1 10μF RUN2 V 100k IN RUN1 90 MODE/SYNC POR RESET 80 L2 L1 0.1 LTC3407-4 V 2.2μH 2.2μH 70 POWER LOSS (W) OUT2 VOUT1 2.5V SW2 SW1 1.8V 60 800mA C5, 22pF C4, 22pF 800mA 50 0.01 40 V V FB2 FB1 EFFICIENCY (%) R4 R2 30 GND C3 R3 R1 C2 0.001 887k 604k 20 10μF 280k 301k 10μF 10 C1, C2, C3: TAIYO YUDEN JMK316BJ106ML L1, L2: MURATA LQH32CN2R2M33 0 0.0001 3407 TA01 *VOUT CONNECTED TO VIN FOR VIN ≤ 2.8V 0.1 1 10 100 1000 LOAD CURRENT (mA)
Figure 1. 2.5V/1.8V at 800mA Step-Down Regulators
34074 TA02 34074fa 1
FEATURES DESCRIPTION
n
High Effi ciency: Up to 95%
The LTC®3407-4 is a dual, constant frequency, synchro- n
Very Low Quiescent Current: Only 40μA
nous step down DC/DC converter. Intended for low power n
2.25MHz Constant Frequency Operation
applications, it operates from 2.5V to 5.5V input voltage n
High Switch Current: 1.2A on Each Channel
range and has a constant 2.25MHz switching frequency, n
No Schottky Diodes Required
allowing the use of tiny, low cost capacitors and induc- n
Low RDS(ON) Internal Switches: 0.35
Ω tors with a profi le ≤1mm. Each output voltage is adjust- n Current Mode Operation for Excellent Line able from 0.6V to 5V. Internal synchronous 0.35Ω, 1.2A and Load Transient Response power switches provide high effi ciency without the need n Short-Circuit Protected for 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 noise ripple for low power effi ciency. Burst n Output Voltages from 5V down to 0.6V Mode® operation provides high effi ciency at light loads, n Power-On Reset Output while pulse-skipping mode provides low noise ripple at n Externally Synchronizable Oscillator light loads. n Small Thermally Enhanced MSOP and 3mm × 3mm DFN Packages To further maximize battery life, the P-channel MOSFETs are turned on continuously in dropout (100% duty cycle),
APPLICATIONS
and both channels draw a total quiescent current of only 40μA. In shutdown, the device draws <1μA. n PDAs/Palmtop PCs n Digital Cameras The LTC3407-4 is identical to the LTC3407-2 except for n Cellular Phones the reduced power-on reset delay time. n Portable Media Players L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks n PC Cards of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815, 6498466, n Wireless and DSL Modems 6611131.
TYPICAL APPLICATION LTC3407-4 Effi ciency/Power Loss Curve
VIN* 2.5V TO 5.5V R5 100 1 C1 10μF RUN2 V 100k IN RUN1 90 MODE/SYNC POR RESET 80 L2 L1 0.1 LTC3407-4 V 2.2μH 2.2μH 70 POWER LOSS (W) OUT2 VOUT1 2.5V SW2 SW1 1.8V 60 800mA C5, 22pF C4, 22pF 800mA 50 0.01 40 V V FB2 FB1 EFFICIENCY (%) R4 R2 30 GND C3 R3 R1 C2 0.001 887k 604k 20 10μF 280k 301k 10μF 10 C1, C2, C3: TAIYO YUDEN JMK316BJ106ML L1, L2: MURATA LQH32CN2R2M33 0 0.0001 3407 TA01 *VOUT CONNECTED TO VIN FOR VIN ≤ 2.8V 0.1 1 10 100 1000 LOAD CURRENT (mA)
Figure 1. 2.5V/1.8V at 800mA Step-Down Regulators
34074 TA02 34074fa 1
