Multi-Output DC-DC Power Supply with VCOM Amplifier and Temperature Sensor for E-Paper Applications

The MAX17135 is a complete power-management IC for E-paper displays that provides source- and gate-driver power supplies, a high-speed VCOM amplifier, and a temperature sensor.

The source-driver power supplies consist of a boost converter and an inverting buck-boost converter that generates +15V (up to +17V) and -15V (up to -17V), respectively. Both source-driver power supplies can deliver up to 200mA. The positive source-driver supply regulation voltage (VPOS) can be set either by using an I²C interface or by connecting an external resistor-divider. The negative source-driver supply voltage (VNEG) is always tightly regulated to -VPOS within ±50mV.

The gate-driver power supplies consist of regulated charge pumps that generate +22V (up to +40V) and -20V (up to -40V) and can deliver up to 20mA each.

The IC features a VCOM amplifier output whose output voltage is controlled by an internal 8-bit digital-to-analog converter (DAC). The DAC is programmable through an I²C interface and allows small-voltage-step sizes per DAC step.

The IC includes a temperature sensor that provides the ability to read the internal IC temperature and an external panel temperature with the use of an external temperature-sensing diode. Temperature output data is supplied through I²C.

The device is available in a space-saving, 32-pin TQFN package and is specified over the -40°C to +85°C extended temperature range.

Applications

* e-Book Readers

* Four Regulated Output Voltages for Source- and Gate-Driver Power Supplies

* VPOS + VNEG = ±50mV Tracking Accuracy

* Measures Internal and Remote Diode Temperature Sensors

* True Shutdown on All Outputs

* 2.7V to 5.5V IN Supply Voltage Range

* Controlled Inrush Current During Soft-Start

* I²C Serial Interface for Temperature Read, Power Output Enable, POS Voltage Regulation Set-Point Adjustment, Power-Up/Power-Down Sequencing Adjustment, and Fault Monitoring