Features and Benefits

  • +1.8V to +6V Input Range
  • Output Voltages
    • +8V Output at 300mA (+2.2V Input Step-Up Switching Regulator)
    • +21V Output at 20mA (Positive Charge Pump)
    • -13V Output at 20mA (Negative Charge Pump)
    • ±150mA High-Current Op-Amp Output
  • Resistor-Adjustable Switching Regulator and Op-Amp Output Range
  • Digitally Programmable Op-Amp Output Voltage
  • +35V to -25V High-Voltage Level-Shifting Drivers
  • Greater than 85% Efficiency (Step-Up Switching Regulator)
  • 1.2MHz Step-Up Switching Frequency
  • SMBus-Compatible Interface
  • Windows 2000/XP/Vista (32-Bit)-Compatible Software
  • 1.2mm Low-Profile Surface-Mount Components
  • Lead-Free and RoHS Compliant
  • Fully Assembled and Tested

Product Details

The MAX8798 evaluation system (EV system) consists of the MAX8798 evaluation kit (EV kit) and the Maxim CMAXQUSB command module. A Windows® 2000/XP/Vista®-compatible software is also available for use with the EV system (MAX8798EVCMAXQU+) and can be downloaded from www.maximintegrated.com/evkitsoftware.

The MAX8798 EV kit (MAX8798EVKIT+) is a fully assembled and tested surface-mount printed-circuit board (PCB) that provides the features required for active-matrix, thin-film transistor (TFT) liquid-crystal displays (LCDs). The EV kit contains a step-up switching regulator, positive two-stage charge pump, negative two-stage charge pump, digitally adjustable VCOM calibration device with nonvolatile memory, SMBus™-compatible interface, high-speed operational amplifier (op amp), and high-voltage, level-shifting scan driver for thin TFT-LCD applications.

The EV kit operates from a DC supply voltage from +1.8V to +6V. The step-up switching regulator is configured for a +8V output providing at least 300mA from a +2.2V input. The positive charge pump is configured for a +21V output providing at least 20mA. The negative charge pump is configured for a -13V output providing at least 20mA. The op amp is capable of providing up to ±150mA peak and features a programmable output voltage initially configured for +3.2V. The high-voltage level-shifting scan driver buffers inputs from STV, CPV, and OE pads and shifts them to a desired level to drive TFT-LCD row logic.

The MAX8798 EV kit demonstrates low quiescent current and high efficiency (> 85%) for maximum battery time per charge. Operation at 1.2MHz allows the use of tiny surface-mount components. The MAX8798 thin QFN package (0.8mm max height), with low-profile external components, allows this circuit to be less than 1.2mm high.

The Maxim CMAXQUSB command module provides the SMBus-compatible interface and is connected to a PC through the universal serial bus (USB) port. The MAX8798 EV kit software provides a graphical user interface (GUI) for exercising the MAX8798 features.


  • LCD Monitor Panels
  • Notebook Computer Display