LTC3256 - Wide VIN Range Dual Output 350mA Step-Down Charge Pump with Watchdog Timer
- Input Voltage Range: 5.5V to 38V
- Independently Enabled 5V and 3.3V Fixed Outputs
- 5V Output: 100mA Max
- 3.3V LDO Output: 250mA Max
- Multimode Step-Down Charge Pump (2:1, 1:1) with Automatic Mode Switching
- Low Quiescent Current
- 20μA with Both Outputs Regulating (No Load)
- 0.5μA in Shutdown
- Engineered for Diagnostic Coverage in ISO26262 Systems
- 1.1V Reference Output for System Diagnostics
- Power-On Reset and Watchdog Controller with Adjustable Timing
- Overcurrent Fault Protection on Each Output
- Overtemperature Protection
- 150°C Max Operating Junction Temperature
- Thermally Enhanced 16-Lead MSOP Package
The LTC3256 is a wide input range switched capacitor step-down DC/DC converter that produces two regulated outputs: a 5V output via direct connection to the charge pump output, and a 3.3V output via a low dropout (LDO) linear post-regulator. The device provides up to 350mA of total output current. At 12V VIN and maximum load on both outputs, power dissipation is reduced by over 2W compared to a dual LDO regulator solution.
The LTC3256 maximizes efficiency by running the charge pump in 2:1 mode over as wide an operating range as pos- sible, and automatically switches to 1:1 mode as needed due to V IN and load conditions. Controlled input current and switching slew rates minimize conducted and radiated EMI. An integrated watchdog timer, independent power good outputs and reset input ensure reliable system operation and fault monitoring. A buffered 1.1V reference output enables system self-testing for safety critical applications.
The LTC3256 has numerous safety features including overcurrent fault protection, overtemperature protection and tolerance of 38V input transients. The LTC3256 is available in a thermally enhanced 16-lead MSOP plastic package with exposed pad (MSE16).
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 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
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Demo BoardsLinear 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.
|DC2375A||LTC3256 Demo Board | Dual Output Step-Down Charge Pump Plus LDO, 5.5V ≤ VIN ≤ 38V, Vout1 = 5V @ 100mA, Vout2 = 3.3V @ 250mA||$100.00|
- Automotive ECU/CAN Transceiver Supplies
- Industrial/Telecom Housekeeping Supplies
- Low Power 12V to 5V and 3.3V Conversion
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