LT8494 - SEPIC/Boost DC/DC Converter with 2A, 70V Switch, and 7μA Quiescent Current
Features
- Low Ripple Burst Mode® Operation:
7μA IQ at 12VIN to 5VOUT
Output Ripple (<10mV Typ.) - Dual Supply Pins:
Improves Efficiency
Reduces Minimum Supply Voltage to ~1V after
Start-Up to Extend Battery Life - Wide Input Voltage Range of ~1V to 60V (2.5V to 32V for Start-Up)
- PG Functional for Input Supply Down to 1.3V
- FMEA Fault Tolerant in TSSOP Package
- Fixed Frequency PWM, SEPIC/BOOST/FLYBACK Topologies
- NPN Power Switch: 2A/70V
- Programmable Switching Frequency: 250kHz to 1.5MHz
- UVLO Programmable on SWEN Pin
- Soft-Start Programmable with One Capacitor
- Small 20-Lead QFN or 20-Lead TSSOP Packages
Typical Application
Description
The LT®8494 is an adjustable frequency (250kHz to 1.5MHz) monolithic switching regulator. Quiescent current can be less than 7μA when operating and is ~0.3μA when SWEN is low. The LT8494 can be configured as either a SEPIC, boost or flyback converter.
The low ripple Burst Mode operation maintains high efficiency at low output current while keeping output ripple below 10mV. Dual supply pins (VIN and BIAS) allow the part to automatically operate from the most efficient supply. Input supply voltage can be up to 60V for SEPIC topologies and up to 32V (with ride-through up to 60V) for boost and flyback topologies. After start-up, battery life is extended since the part can draw current from its output (BIAS) even when VIN voltage drops below 2.5V.
Using a resistor divider on the SWEN pin provides a programmable undervoltage lockout (UVLO) for the converter. A power good flag signals when VOUT reaches 92% of the programmed output voltage.
Additional features such as frequency foldback and softstart are integrated. The LT8494 is available in 20-lead QFN and 20-lead TSSOP packages with exposed pads for low thermal resistance. Fault tolerance in the TSSOP allows for adjacent pin shorts or an open without raising the output voltage above its programmed value.
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 |
|---|---|---|---|---|---|
| LT8494EFE#PBF | TSSOP-20 | FE | E | 05-08-1663 (CB) | Yes |
| LT8494EFE#TRPBF | TSSOP-20 | FE | E | 05-08-1663 (CB) | Yes |
| LT8494EUF#PBF | 4x4 QFN-20 | UF | E | 05-08-1710 | Yes |
| LT8494EUF#TRPBF | 4x4 QFN-20 | UF | E | 05-08-1710 | Yes |
| LT8494HFE#PBF | TSSOP-20 | FE | H | 05-08-1663 (CB) | Yes |
| LT8494HFE#TRPBF | TSSOP-20 | FE | H | 05-08-1663 (CB) | Yes |
| LT8494IFE#PBF | TSSOP-20 | FE | I | 05-08-1663 (CB) | Yes |
| LT8494IFE#TRPBF | TSSOP-20 | FE | I | 05-08-1663 (CB) | Yes |
| LT8494IUF#PBF | 4x4 QFN-20 | UF | I | 05-08-1710 | Yes |
| LT8494IUF#TRPBF | 4x4 QFN-20 | UF | I | 05-08-1710 | 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 | |
|---|---|---|---|---|---|---|
| LT8494EFE#PBF | TSSOP-20 | E | $4.07 | $2.85 | Yes | |
| LT8494EFE#TRPBF | TSSOP-20 | E | $2.91 | Yes | ||
| LT8494EUF#PBF | 4x4 QFN-20 | E | $4.07 | $2.85 | Yes | |
| LT8494EUF#TRPBF | 4x4 QFN-20 | E | $2.91 | Yes | ||
| LT8494HFE#PBF | TSSOP-20 | H | $4.84 | $3.39 | Yes | |
| LT8494HFE#TRPBF | TSSOP-20 | H | $3.45 | Yes | ||
| LT8494IFE#PBF | TSSOP-20 | I | $4.49 | $3.14 | Yes | |
| LT8494IFE#TRPBF | TSSOP-20 | I | $3.20 | Yes | ||
| LT8494IUF#PBF | 4x4 QFN-20 | I | $4.49 | $3.14 | Yes | |
| LT8494IUF#TRPBF | 4x4 QFN-20 | I | $3.20 | 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 |
|---|---|---|---|
| DC2242A | LT8494EFE Demo Board | SEPIC, 3V ≤ VIN ≤ 60V; VOUT = 5V @ 1A | Contact Factory | |
| Buy Now | |||
Applications
- Automotive ECU Power
- Power for Portable Products
- Industrial Supplies
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Design Tools
LTspice
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LT8494
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.
