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4G18N-Rev.F001

5V 6A 1.2MHz Synchronous Boost Converter

EC9288

Load Disconnect

Driving EN to ground places the EC9288 in shutdown mode.

When in shutdown, the internal power MOSFET turns off, all

internal circuitry shuts down and the quiescent supply

current reduces to 1uA maximum. A special circuit is applied

to disconnect the load from the input during shutdown the

converter. In conventional synchronous rectifier circuits, the

back-gate diode of the high side P-FET is forward biased in

shutdown and allows current flowing from the battery to the

output. However, this device uses a special circuit, which

takes the cathode of the back-gate diode of the high-side P-

FET and disconnects it from the source when the regulator is

shutdown. The benefit of this feature for the system design

engineer is that the battery is not depleted during shutdown

of the converter. No additional components must be added

to the design to make sure that the battery is disconnected

from the output of the converter.

Current-Limit Protection

TheEC9288 monitors the inductor current, flowing through

the N-FET, and limits the current peak at current limit level to

prevent loads and the EC9288 from damages during

overload conditions.

Over-Temperature Protection (OTP)

The over-temperature circuit limits the junction temperature

of the EC9288. When the junction temperature exceeds

150℃, a thermal sensor turns off the both N-FET and P-

FET, allowing the devices to cool. The thermal sensor allows

the converters to start a soft-start process and regulate the

output voltage again after the junction temperature cools by

30℃. The OTP is designed with a 30℃ hysteresis to lower

thermal overload conditions, increasing the lifetime of the

device.