Devices, small portable consumer batteries, cheaper, and accepting a variety of input power to achieve the usability requirements engineers to design the system to bring many challenges. Using PowerPath series battery management can effectively address these challenges, is an independent operating characteristics can be independently a wide range of supply (cigarette lighter adapter Ru FireWire input, AC USB, and the battery itself) between Qiehuan transparent implementation of effective management. LP154WE2 LP154WX2 LP154WX3
Handheld battery today engineers design equipment, they are the major challenges facing Suo Yi Xie minimize energy consumption and minimize Tigaoxiaoshuai, simplify design and reduce Chengben.
Many battery-powered portable electronics available today from the AC adapter, car adapter, USB port, or lithium ion / polymer. However, these sequences between different power supply control of self-management has great technical challenge. Throughout, the designers are trying to adopt a “discreet” way to accomplish this function, which uses a large number of MOSFETs, op amps and other discrete components, but during the meeting are likely to cause major system problems, and the influx of hot-plug and other current issues. Recently, even discrete IC solution also needs to use multiple chips to achieve a practical and integrated power management ICs can easily solve these problems. In addition, CI own independent operation also removes an additional termination for the realization of the need for an external microprocessor, thus further simplifying the design. LP154WX4 LP171W01 LP171WP3
When used, such as FireWire, is not regulated high voltage (> 5.5) AC adapter and cigarette lighter adapter, the adapter voltage source and portable devices, the voltage difference between batteries large. Therefore, the linear charger may not be able to solve the problem of high energy consumption, while the use of topology switching IC is able to improve efficiency and reduce thermal management problems. Note that when using USB, Lithium ion polymer battery or adapter input less than 5.5V to power the linear charger device power management is a more appropriate choice.
PowerPath control
With control device from PowerPath USB VBUS power adapter for his own power, and its lithium-ion rechargeable single cell. To ensure that the battery is fully charged when the connection is not used in the state of the bus, the IC directly through the USB bus power the load, rather than receiving power from the battery. Once removed from office, the current through an internal low loss ideal diode current from the battery to the load, thus reducing the voltage drop and power dissipation. LP171WP5 LP171WP6 LP171WX2
Features PowerPath control:
1. Food USB access adapter or battery;
2. In the OUT pin is connected to a circuit application and a battery connected to the power transmission BAT pin (assuming that access to external power, battery);
3. Does the battery charge current is regulated to ensure that the load current and load current and no more to define the boundary USB input current;
4. AC adapter current through an external device (such as power Schottky diodes or FET) connected to the output (load side);
5. With a unique feature, you can use the AC adapter to power the output power to the load while charging the battery;
6. Output pin of the load may be a priority in the current USB input. LT141X7 LT150X3 LTN141W1
Ideal diode
When the output / load current exceeds the input current or voltage input is removed, the ideal diode low loss battery to provide power. The ideal diode (not to load directly connected to the battery) to give the load a fully charged battery can power an external power to maintain full charge before the state abolished. Once the external power source is removed, the output voltage drops until the ideal diode forward bias is applied so far. Canada has the ideal diode voltage before the battery then provides an output to the load. Ideal diode voltage drop much lower than conventional diodes, and reverse leakage current of less. Small forward voltage drop to reduce energy consumption and self-heating, which prolongs the life of the battery.
Ideal diode has the following characteristics:
1. When the output / load current exceeds the input current, or when the input voltage is removed, the ideal diode components for supplying power from the battery; Dell Vostro A860 battery Dell Vostro A860n battery
2. The ideal diode (not to load directly connected to the battery) to give a full load power supply can recharge the battery in the external power source is removed to maintain full charge state Zhi Qian, and makes the unit even in a fully depleted by the battery cases to function properly;
3. Once the external power source is removed, the output voltage drops until the ideal diode forward bias is applied so far. It also has an ideal diode voltage before the battery then provides an output to the load;
4. If the battery is the only power source available or load current exceeds the input current has been set, then the battery will be filed by a bat and pins on the ideal diode circuit between the power transmission automatic load; Dell Vostro 1720 battery Dell Vostro A840 battery
5. Ideal diode (as well as recommended capacitors on pin OUT) allows IC to the body without using large capacitors in the treatment of high dynamic loads and the AC adapter or USB VBUS connection disconnection model /;
6. Ideal diode low loss path to power by reducing the IR drop extended run time battery.
Linear Technology Power Management IC Series for solving design problems above. In the field realize the function of two important new products LTC4085 USB power manager and high-voltage battery charger LTC408 Source Manager. Dell Vostro 1510 battery Dell Vostro 1710 battery