LTC3633A
LTC3633A-1
PRODUCTION
Dual Channel 3A, 20V Monolithic Synchronous Step-Down Regulator
- Part Models
- 16
- 1ku List Price
- Starting From $6.42
Overview
- 3.6V to 20V Input Voltage Range
- 3A Output Current per Channel
- Up to 95% Efficiency
- Low Duty Cycle Operation: 5% at 2.25MHz
- Selectable 0°/180° Phase Shift Between Channels
- Adjustable Switching Frequency: 500kHz to 4MHz
- External Frequency Synchronization
- Current Mode Operation for Excellent Line and Load Transient Response
- 0.6V Reference Allows Low Output Voltages
- User Selectable Burst Mode® Operation or Forced Continuous Mode Operation
- Output Voltage Tracking and Soft-Start Capability
- Short-Circuit Protected
- Overvoltage Input and Overtemperature Protection
- Power Good Status Outputs
- LTC3633: 16V Absolute Maximum VIN
- LTC3633A: 20V Absolute Maximum VIN, Pin Compatible with LTC3633
- Low Profile (4mm × 5mm) QFN-28 and 28-Lead TSSOP Packages
The LTC3633A is a high efficiency, dual-channel monolithic synchronous buck regulator using a controlled on-time, current mode architecture, with phase lockable switching frequency. The two channels can run 180° out of phase to relax the requirements for input and output capacitance. The operating supply voltage range is from 3.6V to 20V, making it suitable for lithium-ion battery stacks as well as point of load power supply applications from a 12V or 5V supply.
The operating frequency is programmable from 500kHz to 4MHz with an external resistor and may be synchronized to an external clock signal. The high frequency capability allows the use of small surface mount inductors and capacitors. The unique constant frequency/controlled ontime architecture is ideal for high step-down ratio applications that operate at high frequency while demanding fast transient response. An internal phase locked loop servos the on-time of the internal one-shot timer to match the frequency of the internal clock or an applied external clock.
The LTC3633A can select between forced continuous mode and high efficiency Burst Mode operation. The LTC3633A and LTC3633A-1 differ in their output voltage sense range (refer to Table 1 in the Operation section of the datasheet for a description of the entire LTC3633A product family).
| Part Number | Output Voltage Sense Range | SVin Input | V2P5 Output | LTC3633 Pin Compatible |
| LTC3633A | 0.6V TO 6V | No | Yes | Yes |
| LTC3633A-1 | 1.5V TO 12V | No | Yes | Yes |
| LTC3633A-2 | 0.6V TO 6V | Yes | No | No |
| LTC3633A-3 | 1.5V TO 12V | Yes | No | No |
Applications
- Distributed Power Systems
- Battery Powered Instruments
- Point of Load Power Supplies
Documentation
Data Sheet 1
User Guide 1
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| LTC3633AEFE#PBF | 28-Lead TSSOP w/ EP | ||
| LTC3633AEFE#TRPBF | 28-Lead TSSOP w/ EP | ||
| LTC3633AEFE-1#PBF | 28-Lead TSSOP w/ EP | ||
| LTC3633AEFE-1#TRPBF | 28-Lead TSSOP w/ EP | ||
| LTC3633AEUFD#PBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3633AEUFD#TRPBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3633AEUFD-1#PBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3633AEUFD-1#TRPBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3633AIFE#PBF | 28-Lead TSSOP w/ EP | ||
| LTC3633AIFE#TRPBF | 28-Lead TSSOP w/ EP | ||
| LTC3633AIFE-1#PBF | 28-Lead TSSOP w/ EP | ||
| LTC3633AIFE-1#TRPBF | 28-Lead TSSOP w/ EP | ||
| LTC3633AIUFD#PBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3633AIUFD#TRPBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3633AIUFD-1#PBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LTC3633AIUFD-1#TRPBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
May 18, 2026 - 26_0072 Epoxy Change for Select TSSOP Products |
||
| LTC3633AEFE#PBF | PRODUCTION | |
| LTC3633AEFE#TRPBF | PRODUCTION | |
| LTC3633AEFE-1#PBF | PRODUCTION | |
| LTC3633AEFE-1#TRPBF | PRODUCTION | |
| LTC3633AIFE#PBF | PRODUCTION | |
| LTC3633AIFE#TRPBF | PRODUCTION | |
| LTC3633AIFE-1#PBF | PRODUCTION | |
| LTC3633AIFE-1#TRPBF | PRODUCTION | |
|
Apr 6, 2022 - 22_0068 Laser Top Mark for ETSSOP and TSSOP Packages Assembled in ADPG [PNG] and UTL |
||
| LTC3633AEFE#PBF | PRODUCTION | |
| LTC3633AEFE#TRPBF | PRODUCTION | |
| LTC3633AEFE-1#PBF | PRODUCTION | |
| LTC3633AEFE-1#TRPBF | PRODUCTION | |
| LTC3633AIFE#PBF | PRODUCTION | |
| LTC3633AIFE#TRPBF | PRODUCTION | |
| LTC3633AIFE-1#PBF | PRODUCTION | |
| LTC3633AIFE-1#TRPBF | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
Can't find the software or driver you need?
Request a Driver/SoftwareHardware Ecosystem
| Parts | Product Life Cycle | Description |
|---|---|---|
| Power System Management (PSM) & Sequencers 1 | ||
| LTC2977 | RECOMMENDED FOR NEW DESIGNS | 8-Channel PMBus Power System Manager Featuring Accurate Output Voltage Measurement |
| Switching Regulators & Controllers 1 | ||
|
LTC3633A-2 LTC3633A-3 |
Dual Channel 3A, 20V Monolithic Synchronous Step-Down Regulator | |
Tools & Simulations
LTspice 1
Models for the following parts are available in LTspice:
- LTC3633
- LTC3633A
- LTC3633A-1
- LTC3633A-2
- LTC3633A-3
LTpowerCAD 2
- LTC3633A Project - Dual 20V 3A, Monolithic Buck Regulator(3.6-20V to 1.5V & 2.5V @ 3A)
- LTC3633A-1 Project - Dual 20V 3A, Monolithic Buck Regulator (3.6-20V to 1.5V & 2.5V @ 3A)
Design tools for the following parts are available in LTpowerCAD:
- LTC3633
- LTC3633-2
- LTC3633A
- LTC3633A-1
- LTC3633A-3
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
LTpowerCAD® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.