Simple solution - with a low IQ and high efficiency switching regulator PMIC

Simple solution - with a low IQ and high efficiency switching regulator PMIC

A wide load range with low quiescent current and operating current and with highly efficient switching regulator IC, laptop battery portable electronic devices help maintain battery life. Linear Technology Corporation (Linear) introduced PMIC with PowerPath control, ultra-low quiescent current and standby current, and first-class integrated functional unit circuits (such as efficient programmable synchronous buck - boost and buck switching regulator device) is simple and easy solution to these design challenges. This was possible because in the PMIC development using different approaches using more optional integration to provide a compact solution without sacrificing performance.

For example, LTC3554 is a suitable lithium ion / polymer battery applications of micro-power multi-PMIC. LTC3554 includes a USB-compatible linear PowerPath manager, a separate battery charger and two high efficiency synchronous buck regulator and a key control circuit, which uses ultra-thin (0.55mm) in the 3mm x 3mm UTQFN package . When all the output to maintain regulation, dell KD476 battery the choice of standby mode pins (see Figure 1) allows the battery current consumption is reduced to only 10μA.

When the LTC3554 USB ports or from a 5V wall adapter to charge the battery up to 400mA current, its PowerPath manager can control the priority of the load, seamless management of multiple-input power supply in order to switch between the power-load . Input is pin-selectable current limit, and the internal settings to meet USB power specification (external resistor required). LTC3554's input voltage allows up to 5.5V, in order to improve robustness, the absolute maximum transient voltage of 7V. The IC's "instant-ON" operation of the properties to ensure that the battery fully discharge even in the case of the system can supply. Its ability to work independently simplifies design, eliminating the need for an external manager to terminate the charge.

LTC3554 includes two built-in synchronous buck regulator, dell GD761 battery which work at 100% duty cycle, and each regulator can supply up to 200mA of output current, adjustable output voltage as low as 0.8V. In order to increase flexibility, the two regulators can be independently controlled to enable and disable, and its oscillation frequency and the corresponding conversion rate is also pin-selectable (1.125MHz or 2.25MHz), to allow the application circuit dynamically efficient and EMI performance to make trade-offs. The IC features high switching frequency allows the use of small-size low-cost capacitors and inductors. The built-in low RDS (ON) switches to increase efficiency up to 93%, and make up the longest battery life. In addition, Burst Mode (Burst Mode) at light loads, optimize efficiency, each regulator quiescent current is only 25μA (in shutdown mode, <1μA), see Figure 1. In addition, the regulator is stable with ceramic capacitors to achieve very low output voltage ripple.

In the light load and load conditions, LTC3554 the buck regulator automatically switches to energy hysteresis control algorithm, which intermittently dell Inspiron 1501 battery controlled switch so that the minimum switching losses. This is called burst mode operation, in this mode, the buck regulator power switch allows the number of cycles sufficient to charge the output capacitor to a point slightly above the voltage regulator. The buck regulator then enter a sleep mode to reduce quiescent current. In this state, power consumption can be reduced to a minimum, while the output capacitor provides the load current. As long as the output voltage down to less regulation point, the buck regulator did give sleep mode wake-up, and again adjust the switch until the output capacitor voltage is slightly higher than the regulator point again. So sleep time depends on load current, dell Inspiron E1505 battery as the load current determine the output capacitor of the discharge rate. If the load current is increased by more than about 50mA, then the buck regulator to be restored to the constant frequency operation.

When the STBY pin is set high to allow all the switching regulator in standby mode. In this mode, the regulator to maintain output regulation at the state and independent buck regulator reduces quiescent current to only 1.5μA. This mode is suitable for a micro-power standby, sleep or memory of "continuing operations" Mode. The load capacity of each regulator can be reduced to 5mA. Standby mode in very light load of circumstances, this time, burst mode operation even in low quiescent current is also considered too big. dell Inspiron 6400 battery