MAX8671X

The MAX8671X integrated power-management IC (PMIC) is ideal for use in portable media players and other handheld devices. In addition to five regulated output voltages, the MAX8671X integrates a 1-cell lithium ion (Li+) or lithium polymer (Li-Poly) charger and Smart Power Selector with dual (AC-to-DC adapter and USB) power inputs. The dual-input Smart Power Selector supports end products with dual or single power connectors. All power switches for charging and switching the system load between battery and external power are included on-chip. No external MOSFETs of MAX8671X are required.

Features of the MAX8671X are:(1)16V-tolerant USB and DC inputs; (2)automatically powers from external power or battery; (3)operates with no battery present; (4)single-cell li+/li-poly charger; (5)three 2MHz Step-down regulators up to 96% efficiency; (6)two low IQ linear regulators; (7)output power-up sequencing; (8)thermal-overload protection.Maxim's Smart Power Selector makes the best use of limited USB or AC-to-DC adapter power. Battery charge current and input current limit are independently set. Input power not used by the system charges the battery. Charge current and DC current limit are programmable up to 1A while USB input current can be set to 100mA or 500mA.

The absolute maximum ratings of the MAX8671X can be summarized as:(1)operating temp:150;(2)USB, DC, PEN1 to AGND:-0.3V to +16V;(3)PG1, PG2, PG3, AGND:-0.3V to +0.3V;(4)BAT continuous current:1.5A;(5)storage temp:-65 to 150;(6)lead temperature (soldering, 10s):300.Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the MAX8671X at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.With a valid DC and/or USB input, the battery charger initiates a charge cycle when the charger is enabled. It first detects the battery voltage. If the battery voltage is less than the prequalification threshold (3.0V), the charger enters prequalification mode in which the battery charges at 10% of the maximum fast-charge current while deeply discharged. Once the battery voltage rises to 3.0V, the charger transitions to fast-charge mode and applies the maximum charge current. As charging continues, the battery voltage rises until it approaches the battery regulation voltage (selected with BVSET) where charge current starts tapering down.