3-channel, fully-integrated ultralow power regulator/switch
The device enables direct connection to an input voltage range of 2.7 V to 15.0 V, allowing the use of multiple alkaline/NiMH or lithium cells and other power sources. The buck regulator in Channel 1 uses a current mode, constant frequency pulse-width modulation (PWM) control scheme for stability and transient performance, and provides up to 800 mA of output current. The automatic PWM/pulse skipping mode (PSM) control scheme maintains efficiency in light output current. A power-good signal indicates that the output of Channel 1 is within 92% of its nominal value.
An ultralow power buck regulator is integrated in Channel 2 with the SYNC/MODE pin to control its operation mode. When SYNC/MODE is set to low, the buck regulator operates in hysteresis mode, and draws only 700 nA of quiescent current to regulate the output under zero load, while being capable of providing up to 50 mA of output current. Hysteresis mode helps achieve excellent efficiency at less than 1 mW and it can work as a keep-alive power supply in a battery-powered system. When the SYNC/MODE pin is set to high, the buck regulator switches to a traditional constant frequency PWM control scheme to provide low output ripple for noise sensitive applications, and the buck regulator provides up to 300 mA of output current in PWM mode.
Channel 3 integrates a high-side load switch that operates from 1.65 V to 5.5 V with its input connected to the output of Channel 2. The load switch provides power domain isolation and extends battery operation time.
Other key safety features of the ADP5310 include overcurrent protection (OCP), thermal shutdown (TSD), and input under-voltage lockout (UVLO). The ADP5310 is rated for the −40°C to +125°C junction temperature range. Use it, ADI suggests, in energy (gas and water) metering; portable and battery-powered equipment; medical applications; and in keep-alive power supplies. The part is priced at $1.99 (1000).