Step-Up Converters Protect Displays From Runaway Output

LCD and organic-LED displays for handheld portable equipment sometimes have problems with runaway outputs from high-voltage boost converters damaging displays. Maxim Integrated Products' MAX8570-MAX8575 high-efficiency step-up converters deal with this with a number of protection features. For instance, no damage is done if an output capacitor or feedback resistor is disconnected or missing. In fact, in response to most fault conditions, the MAX8570 family protects not only itself but also the downstream circuitry. The converters operate from a 2.7- to 5.5-V supply and deliver up to 28 V at the output. They run at up to 87% efficiency and draw 25-µA quiescent current in light-load conditions. The MAX8570 family is offered with 110-, 250-, and 500-mA current limits in both adjustable and fixed output voltages. Prices start at $1.25 in lots of 1000 and up.