The MAX8570 family of LCD step-up converters uses an internal n-channel switch and an internal p-channel output isolation switch. These converters operate from a 2.7V to 5.5V supply voltage and deliver up to 28V at the output. A unique control scheme provides the highest efficiency over a wide range of load conditions. The internal MOSFET switch reduces external component count and a high switching frequency (up to 800kHz) allows for tiny surface-mount components. Three current-limit options are available. The MAX8570 and MAX8572 use a 110mA current limit to reduce ripple and component size in low-current applications. For high-power requirements, the MAX8574 and MAX8575 use a 500mA current limit and supply up to 20mA at 20V. The MAX8571EUT+T and MAX8573 use a 250mA current limit for a compromise between ripple and power. Built-in safety features protect the internal switch and down-stream components from fault conditions. Additional features include a low quiescent current and a True Shutdown mode to save power. The MAX8570/MAX8571/MAX8574 allow the user to set the output voltage between 3V and 28V, and the MAX8572/MAX8573/MAX8575 have a preset 15V output. These step-up converters are ideal for small LCD panels with low current requirements, but can also be used in other applications. The MAX8571EUT+T evaluation kit is available to help reduce design time.
Feature
- 15V or Adjustable Output Voltage Up to 28V
- Safety Features Protect Against Output Faults
- 20mA at 20V from a Single Li+ Battery
- True Shutdown
- 87% Efficiency
- Up to 800kHz Switching Frequency
- Small, 6-Pin SOT23 and μDFN (MAX8570 Only) Packages
Applications
- Cell Phones/Cordless Phones
- Handy Terminals
- LCD Bias Generators
- Organizers
- Palmtop Computers
- PDAs and Other Handheld Devices
- Polymer LEDs (OLED)