LT3667 - 40V 400mA Step-Down Switching Regulator with Dual Fault Protected LDOs
Features
- Triple Output Supply from a Single Input Requires Only One Inductor
- IQ = 50μA at 12VIN to 5V, 3.3V and 2.5V with No Load
- Buck Regulator:
Low Ripple (<15mVP-P) Burst Mode Operation®
400mA Output with Internal Power Switch
4.3V to 40V Input Operation Range (60V Max) - Dual Low Dropout Linear Regulators
200mA Outputs with Programmable Current Limits
1.6V to 45V Input Range
Fault Protected to ±45V - Adjustable 250kHz to 2.2MHz Switching Frequency
- Synchronizable Between 300kHz and 2.2MHz
- Programmable Undervoltage Lockout
- Power Good Indicators
- Available in a Thermally-Enhanced 16-Lead MSOP and 24-Lead (3mm × 5mm) QFN Packages
Typical Application
Description
The LT®3667 is a monolithic triple power supply composed of a 400mA buck switching regulator and two 200mA low dropout linear regulators (LDOs).
The buck regulator includes a high efficiency switch, a boost diode, and the necessary oscillator, control and logic circuitry. Current mode topology is used for fast transient response and good loop stability. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping output ripple below 15mV in a typical application.
Each LDO supplies 200mA of output current with a typical dropout voltage of 340mV, and each LDO has an accurate resistor programmable current limit.
Internal protection circuitry includes reverse-battery protection, current limiting, thermal limiting and reverse current protection.
The LT3667 is available in a thermally-enhanced 16-Lead MSOP and a 24-Pin 3mm x 5mm QFN package with exposed pad for low thermal resistance.
Packaging
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
| Part Number | Package | Code | Temp | Package Drawing |
RoHS |
|---|---|---|---|---|---|
| LT3667EMSE#PBF | MS-16E | MSE | E | 05-08-1667 | Yes |
| LT3667EMSE#TRPBF | MS-16E | MSE | E | 05-08-1667 | Yes |
| LT3667EUDD#PBF | 3x5 QFN-24 | UDD | E | 05-08-1833 | Yes |
| LT3667EUDD#TRPBF | 3x5 QFN-24 | UDD | E | 05-08-1833 | Yes |
| LT3667HMSE#PBF | MS-16E | MSE | H | 05-08-1667 | Yes |
| LT3667HMSE#TRPBF | MS-16E | MSE | H | 05-08-1667 | Yes |
| LT3667HUDD#PBF | 3x5 QFN-24 | UDD | H | 05-08-1833 | Yes |
| LT3667HUDD#TRPBF | 3x5 QFN-24 | UDD | H | 05-08-1833 | Yes |
| LT3667IMSE#PBF | MS-16E | MSE | I | 05-08-1667 | Yes |
| LT3667IMSE#TRPBF | MS-16E | MSE | I | 05-08-1667 | Yes |
| LT3667IUDD#PBF | 3x5 QFN-24 | UDD | I | 05-08-1833 | Yes |
| LT3667IUDD#TRPBF | 3x5 QFN-24 | UDD | I | 05-08-1833 | Yes |
Order Info
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LT3667EMSE#PBF | MS-16E | E | $3.64 | $2.55 | Yes | |
| LT3667EMSE#TRPBF | MS-16E | E | $2.61 | Yes | ||
| LT3667EUDD#PBF | 3x5 QFN-24 | E | $3.64 | $2.55 | Yes | |
| LT3667EUDD#TRPBF | 3x5 QFN-24 | E | $2.61 | Yes | ||
| LT3667HMSE#PBF | MS-16E | H | $4.37 | $3.06 | Yes | |
| LT3667HMSE#TRPBF | MS-16E | H | $3.12 | Yes | ||
| LT3667HUDD#PBF | 3x5 QFN-24 | H | $4.37 | $3.06 | Yes | |
| LT3667HUDD#TRPBF | 3x5 QFN-24 | H | $3.12 | Yes | ||
| LT3667IMSE#PBF | MS-16E | I | $4.00 | $2.81 | Yes | |
| LT3667IMSE#TRPBF | MS-16E | I | $2.87 | Yes | ||
| LT3667IUDD#PBF | 3x5 QFN-24 | I | $4.00 | $2.81 | Yes | |
| LT3667IUDD#TRPBF | 3x5 QFN-24 | I | $2.87 | Yes | ||
| Buy Now • Request Samples | ||||||
Demo Boards
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC1869A | LT3667 Demo Board | Buck Plus Dual Fault-Protected LDOs, 6V ≤ VIN ≤40V, Vout1 = 5V, Vout2/Vout3 = 3.3V/2.5V @ 200mA | $125.00 | |
| Buy Now | |||
Applications
- Automotive Battery Regulation
- Power for Portable Instrumentation
- Industrial Supplies
- Fault-Protected Sensor Supply
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Design Tools
LTspice
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LT3667
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
