The TPS60251 is a high efficiency, constant frequency charge pump DC/DC converter that uses a dual mode 1× and 1.5× conversion to maximize efficiency over the input voltage range. It drives up to five white LEDs for a main display and up to two white LEDs for a sub display with regulated constant current for uniform intensity. By utilizing adaptive 1×/1.5× charge pump modes and very low-dropout current regulators, the TPS60251 achieves high efficiency over the full 1-cell lithium-battery input voltage range.

Four enable inputs, ENmain, ENsub1, ENsub2, and ENaux, available through I2C, are used for simple on/off controls for the main, sub1, sub2, and DM5 displays, respectively. To lower operating current when using one sub display LED, the device provides independent operation in sub display LEDs.

The TPS60251 is available in a 24-pin 4mmx4mm thin QFN.

• 3.0-V to 6.0-V Input Voltage Range
• ×1 and ×1.5 Charge Pump
• Fully Programmable Current with I2C
  • 64 Dimming Steps with 25mA Maximum (Sub and Main Display Banks)
  • 4 Dimming Steps with 80mA Maximum (DM5 for Auxiliary Application)
• 2% Current Matching for Sub LEDs at Light Load Condition (Each 100µA)
• 750-kHz Charge Pump Frequency
• Continuous 230-mA Maximum Output Current
• Auto Switching Between ×1 and ×1.5 Mode for Maximum Efficiency
• Built-in Soft Start and Current Limit
• Hardware Enable/Disable
• Open Lamp Detection
• 24-Pin 4mm x 4mm QFN
• APPLICATIONS
  • Cellular Phones
  • PDA, PMP, GPS (Up To 4 Inch Display)
  • Multidisplay Handheld Devices