The LTC3458 is a high efficiency, current mode, fixed frequency step-up DC/DC converter with true output disconnect and inrush current limiting. It is rated for a 7.5V output and includes a 0.3Ω N-channel MOSFET switch and a 0.4Ω P-channel MOSFET synchronous rectifier. Output voltage, switching frequency and loop compensation are programmable, and the oscillator can be set up to 1.5MHz or synchronized to an external clock. Quiescent current is 15µA during Burst Mode operation.
The datasheet covers features, applications, absolute maximum ratings, package and order information, electrical characteristics and typical performance characteristics. The pin functions section gives the formulas for programming peak current limit with a resistor on ILIM, oscillator frequency with a resistor on RT, soft-start with a capacitor on SS, and the Burst Mode threshold with a resistor/capacitor on BURST. The device is offered in a low profile (0.75mm), 3mm × 4mm 12-pin DFN package.
| Input voltage range | 1.5V to 6V |
|---|---|
| Output voltage range | 2.0V to 7.5V (adjustable) |
| Efficiency | Up to 93% |
| Switch on resistance | 0.3Ω N-channel, 0.4Ω P-channel at 5VOUT |
| Quiescent current | 15µA in Burst Mode, <1µA in shutdown |
| Switching frequency | Programmable/synchronizable up to 1.5MHz |
| Output current | 700mA at 7V from 5V input |
| Operating temperature range | –40°C to 85°C |
| Package | 3mm × 4mm 12-pin DFN, 0.75mm profile |
| Feedback reference voltage | 1.23V typical |
The LTC3458 operates from a 1.5V to 6V input range.
The output voltage is adjustable from 2V to 7.5V, and the device is rated for a 7.5V output.
Connect a resistor from the RT pin to ground to program the oscillator frequency, or synchronize the oscillator to an external clock.
Yes, the LTC3458 has true output disconnect and inrush current limiting.