Tiny PMIC makes the most of battery runtime

The LTC3586 claims Linear Technology Corp. is the latest and most highly integrated PMIC in a family of multi-function, compact power management solutions for Li-ion/polymer battery applications. The LTC3586 integrates a switching PowerPath manager, a stand-alone battery charger, always-on LDO, and four high efficiency synchronous switching regulators: one buck-boost, one boost, and two buck regulators, all in a compact, low-profile 4mm x 6mm QFN package. According to Linear, the LTC3586's PowerPath control seamlessly manages power flow between multiple input sources such as a wall adapter or USB port and the Lithium battery while preferentially providing power to the system load. In addition, the "instant-ON" operation ensures system load power even with a dead battery. For fast charging, the LTC3586's switching input stage converts nearly all of the 2.5W available from the USB port to charging current, enabling up to 700mA from a 500mA limited USB supply or up to 1.5A when wall powered. An internal 180m? ideal diode plus optional external ideal diode controller provide a low loss power path, further minimizing heat generation and maximizing efficiency.

The LTC3586's buck-boost regulator can deliver up to 1A continuously and is ideal for efficiently regulating a 3.3V output over the full Lithium battery voltage range, down to 2.75V. The LTC3586's two buck regulators feature 100 percent duty cycle operation and are capable of delivering output currents of 400mA each, with adjustable output voltages down to 0.8V. The boost regulator is capable of at least 800mA output current and is programmable up to a 5V output. The LTC3586's internal low R_DS(ON) switches enable switching buck and buck-boost efficiencies as high as 94 percent, maximizing battery run time. In addition, Burst Mode operation optimizes efficiency at light loads with a quiescent current of only 25?A for the buck-boost regulator and only 35?A for each buck regulator (The LTC3586 features USB-compatible programmable input current limiting to 100mA/500mA/1A, while its Bat-Track adaptive output control enables high efficiency battery charging with minimum power dissipation. To preserve battery energy, the LTC3586 draws only 44?A in suspend mode. The charger is compatible with inputs up to 5.5V (7V absolute maximum transient for added robustness).

The LTC3586 is available from stock in a compact, low-profile (0.75mm) 4mm x 6mm QFN-38 package. Pricing starts at $5.30 each for 1,000-piece quantities.