资 源 简 介
The ISL6237 dual step-down, switch-mode power-supply(SMPS) controller generates logic-supply voltages inbattery-powered systems. The ISL6237 includes twopulse-width modulaTIon (PWM) controllers, 5V/3.3V and1.5V/1.05V. The output of SMPS1 can also be adjusted from0.7V to 5.5V. The SMPS2 output can be adjusted from 0.5V to2.5V by setTIng REFIN2 voltage. This device features a linearregulator providing 3.3V/5V, or adjustable from 0.7V to 4.5Voutput via LDOREFIN. The linear regulator provides up to100mA output current with automaTIc linear-regulatorbootstrapping to the BYP input. When in switchover, the LDOoutput can source up to 200mA. The ISL6237 includeson-board power-up sequencing, power-good (POK_) outputs,digital soft-start, and internal soft-stop output discharge thatprevents negaTIve voltages on shutdown.Constant on-time PWM control scheme operates withoutsense resistors and provides 100ns response to loadtransients while maintaining a relatively constant switchingfrequency. The unique ultrasonic pulse-skipping modemaintains the switching frequency above 25kHz, whicheliminates noise in audio applications. Other features includepulse skipping, which maximizes efficiency in light-loadapplications, and fixed-frequency PWM mode, which reducesRF interference in sensitive applications.
