Datasheet LTC3412A (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 3A, 4MHz, Monolithic Synchronous Step-Down Regulator |
| Pages / Page | 20 / 1 — FEATURES. DESCRIPTION. High Efficiency: Up to 95%. 3A Output Current. Low … |
| File Format / Size | PDF / 460 Kb |
| Document Language | English |
FEATURES. DESCRIPTION. High Efficiency: Up to 95%. 3A Output Current. Low Quiescent Current: 64µA
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LTC3412A 3A, 4MHz, Monolithic Synchronous Step-Down Regulator
FEATURES DESCRIPTION
n
High Efficiency: Up to 95%
The LTC®3412A is a high efficiency monolithic synchro- n
3A Output Current
nous, step-down DC/DC converter utilizing a constant n
Low Quiescent Current: 64µA
frequency, current mode architecture. It operates from n
Low RDS(ON) Internal Switch: 77mΩ
an input voltage range of 2.25V to 5.5V and provides a n
2.25V to 5.5V Input Voltage Range
regulated output voltage from 0.8V to 5V while deliver- n Programmable Frequency: 300kHz to 4MHz ing up to 3A of output current. The internal synchronous n ±2% Output Voltage Accuracy power switch with 77mΩ on-resistance increases efficiency n 0.8V Reference Allows Low Output Voltage and eliminates the need for an external Schottky diode. n Selectable Forced Continuous/Burst Mode® Operation Switching frequency is set by an external resistor or can with Adjustable Burst Clamp be synchronized to an external clock. 100% duty cycle n Synchronizable Switching Frequency provides low dropout operation extending battery life in n Low Dropout Operation: 100% Duty Cycle portable systems. OPTI-LOOP® compensation allows the n Power Good Output Voltage Monitor transient response to be optimized over a wide range of n Overtemperature Protected loads and output capacitors. n Available in 16-Lead Exposed Pad TSSOP and QFN Packages The LTC3412A can be configured for either Burst Mode operation or forced continuous operation. Forced continu-
APPLICATIONS
ous operation reduces noise and RF interference while Burst Mode operation provides high efficiency by reducing n Point-of-Load Regulation gate charge losses at light loads. In Burst Mode operation, n Notebook Computers external control of the burst clamp level allows the output n Portable Instruments voltage ripple to be adjusted according to the application n Distributed Power Systems requirements. L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, Linear Technology and the Linear logo are registered trademarks and ThinSOT is a trademark of Analog Devices, Inc. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, 6724174.
TYPICAL APPLICATION
22µF VIN
Efficiency and Power Loss
3.3V 100 100000 PVIN SVIN 95 EFFICIENCY 2.2M RT PGOOD 90 10000 LTC3412A 0.47µH 294k POWER LOSS (mW) SW VOUT 85 2.5V AT 3A C 80 1000 RUN/SS PGND OUT 100µF 75 1000pF 12.1k ×2 ITH SGND 70 100 SYNC/MODE V EFFICIENCY (%) FB 65 820pF POWER LOSS 60 10 69.8k 392k 115k 55 3412A F01a 50 1 0.01 0.1 1 10 LOAD CURRENT (A)
Figure 1. 2.5V/3A Step-Down Regulator
3412A F01b 3412aff Fo F r o rmo m r o e r e inf n o f r o m r a m t a iton o n ww w w w . w line n a e r a .rco c m o / m L / T L C T 3 C 41 3 2 41 A 2 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Related Parts
FEATURES DESCRIPTION
n
High Efficiency: Up to 95%
The LTC®3412A is a high efficiency monolithic synchro- n
3A Output Current
nous, step-down DC/DC converter utilizing a constant n
Low Quiescent Current: 64µA
frequency, current mode architecture. It operates from n
Low RDS(ON) Internal Switch: 77mΩ
an input voltage range of 2.25V to 5.5V and provides a n
2.25V to 5.5V Input Voltage Range
regulated output voltage from 0.8V to 5V while deliver- n Programmable Frequency: 300kHz to 4MHz ing up to 3A of output current. The internal synchronous n ±2% Output Voltage Accuracy power switch with 77mΩ on-resistance increases efficiency n 0.8V Reference Allows Low Output Voltage and eliminates the need for an external Schottky diode. n Selectable Forced Continuous/Burst Mode® Operation Switching frequency is set by an external resistor or can with Adjustable Burst Clamp be synchronized to an external clock. 100% duty cycle n Synchronizable Switching Frequency provides low dropout operation extending battery life in n Low Dropout Operation: 100% Duty Cycle portable systems. OPTI-LOOP® compensation allows the n Power Good Output Voltage Monitor transient response to be optimized over a wide range of n Overtemperature Protected loads and output capacitors. n Available in 16-Lead Exposed Pad TSSOP and QFN Packages The LTC3412A can be configured for either Burst Mode operation or forced continuous operation. Forced continu-
APPLICATIONS
ous operation reduces noise and RF interference while Burst Mode operation provides high efficiency by reducing n Point-of-Load Regulation gate charge losses at light loads. In Burst Mode operation, n Notebook Computers external control of the burst clamp level allows the output n Portable Instruments voltage ripple to be adjusted according to the application n Distributed Power Systems requirements. L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, Linear Technology and the Linear logo are registered trademarks and ThinSOT is a trademark of Analog Devices, Inc. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, 6724174.
TYPICAL APPLICATION
22µF VIN
Efficiency and Power Loss
3.3V 100 100000 PVIN SVIN 95 EFFICIENCY 2.2M RT PGOOD 90 10000 LTC3412A 0.47µH 294k POWER LOSS (mW) SW VOUT 85 2.5V AT 3A C 80 1000 RUN/SS PGND OUT 100µF 75 1000pF 12.1k ×2 ITH SGND 70 100 SYNC/MODE V EFFICIENCY (%) FB 65 820pF POWER LOSS 60 10 69.8k 392k 115k 55 3412A F01a 50 1 0.01 0.1 1 10 LOAD CURRENT (A)
Figure 1. 2.5V/3A Step-Down Regulator
3412A F01b 3412aff Fo F r o rmo m r o e r e inf n o f r o m r a m t a iton o n ww w w w . w line n a e r a .rco c m o / m L / T L C T 3 C 41 3 2 41 A 2 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Related Parts
