The MAX5025–MAX5028 constant-frequency, pulsewidth modulating (PWM), low-noise boost converters are intended for low-voltage systems that often need a locally generated high voltage. These devices are capable of generating low-noise, high output voltages required for varactor diode biasing in TV tuners, set-top boxes, and PCI cable modems. The MAX5025– MAX5028 operate from as low as 3V and switch at 500kHz. The constant-frequency, current-mode PWM architecture provides for low output noise that is easy to filter. A 40V lateral DMOS device is used as the internal power switch, making the devices ideal for boost converters up to 36V. The MAX5025/MAX5026 adjustable versions require the use of external feedback resistors to set the output voltage. The MAX5027/MAX5028 offer a fixed 30V output. These devices are available in a small, 6- pin SOT23 package. Applications TV Tuner Power Supply Low-Noise Varactor Diode Biasing Set-Top Box Tuner Power Supply PCI Cable Modem Voice-Over-Cable LCD Power Supply Avalanche Photodiode Biasing