LT1579 - 300mA Dual Input Smart Battery Backup Regulator
Features
- Maintains Output Regulation with Dual Inputs
- Dropout Voltage: 0.4V
- Output Current: 300mA
- 50µA Quiescent Current
- No Protection Diodes Needed
- Two Low-Battery Comparators
- Status Flags Aid Power Management
- Adjustable Output from 1.5V to 20V
- Fixed Output Voltages: 3V, 3.3V and 5V
- 7µA Quiescent Current in Shutdown
- Reverse-Battery Protection
- Reverse Current Protection
- Remove, Recharge and Replace Batteries Without Loss of Regulation
Typical Application
Description
The LT1579 is a dual input, single output, low dropout regulator. This device is designed to provide an uninterruptible output voltage from two independent input voltage sources on a priority basis. All of the circuitry needed to switch smoothly and automatically between inputs is incorporated.The LT1579 can supply 300mA of output current from either input at a dropout voltage of 0.4V. Quiescent current is 50µA, dropping to 7µA in shutdown. Two comparators are included to monitor input voltage status. Two additional status flags indicate which input is supplying power and provide an early warning against loss of output regulation when both inputs are low. A secondary select pin is provided so that the user can force the device to switch from the primary input to the secondary input. Internal protection circuitry includes reverse-battery protection, current limiting, thermal limiting and reverse-current protection.
The device is available in fixed output voltages of 3V, 3.3V and 5V, and as an adjustable device with a 1.5V reference voltage. The LT1579 regulators are available in narrow 16-lead SO and 16-lead SSOP packages with all features, and in SO-8 with limited features.
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 |
|---|---|---|---|---|---|
| LT1579CGN-3.3#PBF | SSOP-16 | GN | C | 05-08-1641 (GN16) | Yes |
| LT1579CGN-3.3#TRPBF | SSOP-16 | GN | C | 05-08-1641 (GN16) | Yes |
| LT1579CGN-3#PBF | SSOP-16 | GN | C | 05-08-1641 (GN16) | Yes |
| LT1579CGN-3#TRPBF | SSOP-16 | GN | C | 05-08-1641 (GN16) | Yes |
| LT1579CGN-5#PBF | SSOP-16 | GN | C | 05-08-1641 (GN16) | Yes |
| LT1579CGN-5#TRPBF | SSOP-16 | GN | C | 05-08-1641 (GN16) | Yes |
| LT1579CGN#PBF | SSOP-16 | GN | C | 05-08-1641 (GN16) | Yes |
| LT1579CGN#TRPBF | SSOP-16 | GN | C | 05-08-1641 (GN16) | Yes |
| LT1579CS-3.3#PBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LT1579CS-3.3#TRPBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LT1579CS-3#PBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LT1579CS-3#TRPBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LT1579CS-5#PBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LT1579CS-5#TRPBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LT1579CS#PBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LT1579CS#TRPBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LT1579CS8-3.3#PBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1579CS8-3.3#TRPBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1579CS8-3#PBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1579CS8-3#TRPBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1579CS8-5#PBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1579CS8-5#TRPBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1579CS8#PBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1579CS8#TRPBF | SO-8 | S8 | C | 05-08-1610 (S8) | Yes |
| LT1579IGN-3.3#PBF | SSOP-16 | GN | I | 05-08-1641 (GN16) | Yes |
| LT1579IGN-3.3#TRPBF | SSOP-16 | GN | I | 05-08-1641 (GN16) | Yes |
| LT1579IGN-3#PBF | SSOP-16 | GN | I | 05-08-1641 (GN16) | Yes |
| LT1579IGN-3#TRPBF | SSOP-16 | GN | I | 05-08-1641 (GN16) | Yes |
| LT1579IGN-5#PBF | SSOP-16 | GN | I | 05-08-1641 (GN16) | Yes |
| LT1579IGN-5#TRPBF | SSOP-16 | GN | I | 05-08-1641 (GN16) | Yes |
| LT1579IGN#PBF | SSOP-16 | GN | I | 05-08-1641 (GN16) | Yes |
| LT1579IGN#TRPBF | SSOP-16 | GN | I | 05-08-1641 (GN16) | 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
sales office or authorized distributor.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.Click here to view our complete list of demo boards
Applications
- Dual Battery Systems
- Battery Backup Systems
- Automatic Power Management for Battery-Operated Systems
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