The MAX1531 evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board that provides logic and bias power required for liquid crystal display (LCD) monitors. The EV kit contains a step-down switching regulator, a logic-supply linear regulator, a source-driver-supply linear regulator, a gamma-reference linear regulator, a two-stage positive charge pump and linear regulator for the TFT gate-on supply, and a one-stage negative charge pump and linear regulator for the TFT gate-off supply. The source-driver supply, the gamma-reference supply, the gate-on supply, and the gate-off supply can be sequenced in any power-up order. The EV kit also includes a MAX1522 step-up switching regulator to provide a higher output voltage option for the source-driver supply and the gamma reference.
The EV kit produces the output voltages listed in the features column using a +10.5V to +24V input voltage range. The input range can be reduced to +9.5V if the included MAX1522 step-up regulator circuit is used. If lower output voltages are acceptable, the input range can be further reduced to +8V.
The EV kit features undervoltage protection for the input, overcurrent protection for the step-down switching regulator, and overload protection for the sourcedrive linear regulator. Operation at 500kHz allows the use of small surface-mount components. The EV kit also evaluates the MAX1530.