MIC23099

MIC23099 Single AA/AAA Cell Step-Up/Step-Down Regulators with Battery Monitoring General Description The MIC23099 is a high-efficiency, low-noise, dual-output, integrated power-management solution for single-cell alkaline or NiMH battery applications. The synchronous boost output voltage (VOUT1) is enabled first and is powered from the battery. Next the synchronous buck output (VOUT2), which is powered from the boost output voltage, is enabled. This configuration allows VOUT2 to be independent of battery voltage, thereby allowing the buck output voltage to be higher or lower than the battery voltage. To minimize switching artifacts in the audio band, both the converters are design to operate with a minimum switching frequency of 80kHz for the buck and 100kHz for the boost. The high current boost has a maximum switching frequency of 1MHz, minimizing the solution footprint. The MIC23099 incorporates both battery-management functions and fault protection. The low-battery level is indicated by an external LED connected to the LED pin. In addition, a supervisory circuit monitors each output and asserts a power-good (PG) signal when the sequencing is done or de-asserted when a fault condition occurs. Datasheets and support documentation are available on Micrel’s web site at: www.micrel.com. Features VIN range from 0.85V to 1.6V VOUT1 (step-up) adjustable from 1.8V to 3.3V VOUT2 (step-down) adjustable from 1.0V to VOUT2 VOUT1/400mW and VOUT2/30mA from a single cell Minimizes switc...