LT3694
PRODUCTION36V, 2.6A Monolithic Buck Regulator With Dual LDO
- Part Models
- 16
- 1ku List Price
- Starting From $5.82
Overview
- Wide Input Range: 4V to 36V
- Overvoltage Shutdown Protects Circuit Through 70V Transients
- 2.6A Output Switching Regulator with Internal Power Switch
- Dual, Low Dropout, Linear Regulator Controllers with Programmable Current Limit
- Tracking/Soft-Start Inputs and Power Good Output Simplify Soft-Start and Supply Sequencing
- Uses Small Inductors and Ceramic Capacitors
- VOUT(MIN) = 0.75V (Buck and LDOs)
- Adjustable 250kHz to 2.5MHz Switching Frequency
- Accurate Enable Threshold Allows User Programmable Undervoltage Lockout
- Options for Clock Synchronization (LT3694) or Clock Output to Enable Synchronization to Other Switching Regulators (LT3694-1)
- Thermally Enhanced 28-Lead 4mm × 5mm QFN and 20-Lead TSSOP Packages
The LT3694/LT3694-1 are monolithic, current mode DC/DC converters with dual, low dropout regulator controllers. The switching converter is a step-down converter capable of generating up to 2.6A at its output. Each regulator has independent track/soft-start circuits simplifying power supply sequencing and interfacing with microcontrollers and DSPs.
The switching frequency is set with a single resistor with a range of 250kHz to 2.5MHz. The high switching frequency permits the use of small inductors and ceramic capacitors leading to very small triple output solutions. The constant-switching frequency, combined with low impedance ceramic capacitors, results in low, predictable output ripple. Protection circuitry senses the current in the power switch and external Schottky catch diode to protect the LT3694 against short-circuit conditions. Frequency foldback and thermal shutdown provide additional protection.
With its wide input voltage range of 4V to 36V, the LT3694 regulates a broad array of power sources from 4-cell batteries and 5V logic rails to unregulated wall transformers, lead acid batteries and distributed power supplies. The LT3694 can be synchronized to an external clock with the SYNC pin while the LT3694-1 offers a CLKOUT pin allowing other DC/DC converters to synchronize to the LT3694-1 clock.
Applications
- Automotive
- Industrial
- DSL and Cable Modems
- Distributed Power Regulation
- Wall Transformer Regulation
Documentation
Data Sheet 1
User Guide 1
Technical Articles 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 |
|---|---|---|---|
| LT3694EFE#PBF | 20-Lead TSSOP w/ EP | ||
| LT3694EFE#TRPBF | 20-Lead TSSOP w/ EP | ||
| LT3694EFE-1#PBF | 20-Lead TSSOP w/ EP | ||
| LT3694EFE-1#TRPBF | 20-Lead TSSOP w/ EP | ||
| LT3694EUFD#PBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LT3694EUFD#TRPBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LT3694EUFD-1#PBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LT3694EUFD-1#TRPBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LT3694IFE#PBF | 20-Lead TSSOP w/ EP | ||
| LT3694IFE#TRPBF | 20-Lead TSSOP w/ EP | ||
| LT3694IFE-1#PBF | 20-Lead TSSOP w/ EP | ||
| LT3694IFE-1#TRPBF | 20-Lead TSSOP w/ EP | ||
| LT3694IUFD#PBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LT3694IUFD#TRPBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LT3694IUFD-1#PBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) | ||
| LT3694IUFD-1#TRPBF | 28-Lead QFN (4mm x 5mm x 0.75mm w/ EP) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Apr 6, 2022 - 22_0068 Laser Top Mark for ETSSOP and TSSOP Packages Assembled in ADPG [PNG] and UTL |
||
| LT3694EFE#PBF | PRODUCTION | |
| LT3694EFE#TRPBF | PRODUCTION | |
| LT3694EFE-1#PBF | PRODUCTION | |
| LT3694EFE-1#TRPBF | PRODUCTION | |
| LT3694IFE#PBF | PRODUCTION | |
| LT3694IFE#TRPBF | PRODUCTION | |
| LT3694IFE-1#PBF | PRODUCTION | |
| LT3694IFE-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 |
|---|---|---|
| Circuit Monitors 1 | ||
| LTC2960 | RECOMMENDED FOR NEW DESIGNS | 36V Nano-Current Two-Input Voltage Monitor |
| Hot Swap Controllers 1 | ||
| LT4363 | RECOMMENDED FOR NEW DESIGNS | High Voltage Surge Stopper with Current Limit |
| Power System Management (PSM) & Sequencers 1 | ||
| LTC2974 | RECOMMENDED FOR NEW DESIGNS | 4-Channel PMBus Power System Manager Featuring Accurate Output Current Measurement |
| Switching Regulators & Controllers 1 | ||
| LTC3880 | RECOMMENDED FOR NEW DESIGNS | Dual Output PolyPhase Step-Down DC/DC Controller with Digital Power System Management |
Tools & Simulations
LTspice 2
- LT3694-1 Demo Circuit - 36V Buck Regulator w/ Dual LDO and Clock Out (12V to 3.3V@1.7A, 2.5V@450mA & 1.8V@450mA)
- LT3694 Demo Circuit - 36V Buck Regulator w/ Dual LDO and Sync In (12V to 3.3V@1.7A, 2.5V@450mA & 1.8V@450mA)
Models for the following parts are available in LTspice:
- LT3694
- LT3694-1
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.
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