The LM3224 is a step-up DC/DC converter from National Semiconductor with a 0.15Ω (typ.), 2.45A (typ.) internal switch and pin selectable operating frequency. With the ability to convert 3.3V to multiple outputs of 8V, -8V, and 23V, the LM3224 is an ideal part for biasing TFT displays. With the high current switch it is also ideal for driving high current white LEDs for flash applica- tions.
The LM3224 is a step‑up DC/DC converter that can boost 3.3 V to multiple outputs such as 8 V, –8 V, and 23 V, making it suitable for TFT bias supplies, handheld devices, and white‑LED flash applications. It features a 0.15 µJ typical switching loss, a 2.45 A internal switch, and selectable 615 kHz or 1.25 MHz switching frequencies for easy filtering and low noise.
Key specifications are listed in the electrical characteristics section, including an operating voltage range of 2.7 V to 7 V, a maximum output voltage of 20 V, and a quiescent current of about 1.3 mA. Pin functions such as SHDN (active‑low shutdown) and FSLCT (frequency selection) are described, and the device is supplied in an 8‑lead MSOP package.
| Operating voltage range | 2.7 V to 7 V |
|---|---|
| Switching frequency | 615 kHz or 1.25 MHz (pin selectable) |
| Internal switch current rating | 2.45 A (typ.) |
| Package | 8‑lead MSOP |
The LM3224 operates from 2.7 V to 7 V input voltage.
SHDN is an active‑low shutdown control; it defaults off and must be pulled high to enable the device.