The LM2717 is a dual step-down DC/DC converter composed of two PWM DC/DC buck (step-down) converters. The first converter is used to generate a fixed output voltage of 3.3V. The second converter is used to generate an adjustable output voltage. Both converters feature low RDSON (0.16Ω) internal switches for maximum efficiency. Operating frequency can be adjusted anywhere between 300kHz and 600kHz allowing the use of small external components. External soft-start pins for each enables the user to tailor the soft-start times to a specific application. Each converter may also be shut down independently with its own shutdown pin. The LM2717 is available in a low profile 24-lead TSSOP package ensuring a low profile overall solution.
The LM2717 integrates two PWM buck converters in a single 24‑lead TSSOP package. The first converter provides a fixed 3.3 V output at up to 2.2 A, while the second offers an adjustable output up to 3.2 A. Both converters use low‑Rds(on) internal switches for high efficiency and feature independent shutdown pins and soft‑start pins.
The device operates from a 4 V to 20 V input range, with a selectable switching frequency between 300 kHz and 600 kHz set via the FSLCT pin. Typical applications include TFT‑LCD displays, handheld devices, portable equipment and laptop computers. Detailed pin descriptions, absolute maximum ratings, and performance curves are provided in the document.
| Fixed buck output voltage | 3.3 V |
|---|---|
| Fixed buck output current | 2.2 A |
| Adjustable buck output current | 3.2 A |
| Input voltage range | 4 V to 20 V |
| Operating frequency range | 300 kHz to 600 kHz |
| Package | 24‑lead TSSOP |
| Maximum input voltage (Vin) | -0.3 V to 22 V |
The fixed buck converter provides a 3.3 V output.
The frequency is set with the FSLCT pin using a resistor, allowing selection between 300 kHz and 600 kHz.
It is supplied in a 24‑lead TSSOP package.
The device can operate with an input voltage from –0.3 V up to 22 V (typical range 4 V to 20 V).