Ⅰ. Power management of traditional vehicle tracker system
Traditional linear topology battery chargers are often valued for their compact size, simplicity, and low cost. However, traditional linear chargers have the following disadvantages: limited input and battery voltage ranges, high relative current consumption, excessive power dissipation (heating), limited charge termination algorithms, and relatively low efficiency. On the other hand, switch-mode battery chargers are popular due to their topology, flexibility, multi-chemical charging, high charging efficiency (very low heat generation, enabling fast charging), and wide operating voltage range. Of course, there are always drawbacks.
Some of the disadvantages of switching chargers include relatively high cost, more complex inductor-based designs, potential noise, and larger solution size. Due to the above advantages, modern lead-acid, wireless power, energy harvesting, solar charging, remote sensor and embedded automotive applications mainly use switch mode chargers.
Traditionally, a tracker's backup power management system consists of multiple ICs, high-voltage buck regulators, battery chargers, and discrete components, and is not a truly compact solution. Therefore, early tracking systems were not very compact in form factor. Typical applications for vehicle tracker systems are the use of car batteries and single-cell Li-ion batteries for storage and power backup.
Ⅱ. Why does the vehicle tracker system need a more integrated power management solution?
The main reason is that the size of the GPS tracker products itself needs to shrink, and this market pursues the smaller the better. There is also the need to safely charge the battery, protect the IC from voltage transients, backup the power system to prevent the system power from disappearing or failing, and provide a relatively low power supply voltage (about 4.45 V) for the general packet radio service (GPRS) chipset.
To achieve these goals, an integrated backup power manager and charger solution requires the following features:
1. High-efficiency synchronous buck topology;
2. Wide input voltage range to adapt to various input power sources, and has protection against high voltage transients;
3. Appropriate battery charging voltage to support GPRS chipset;
4. Simple autonomous operation with on-board charge termination (no microcontroller required);
5. PowerPath control, it can seamlessly switch between the input power supply and the backup power supply when a power failure event occurs; if an input short circuit occurs, it also needs to provide reverse blocking;
6. When the input does not exist or fails, supply power to the vehicle tracker system load through the backup battery;
7. Due to space constraints, the size and thickness of the solution should be small;
8. Adopt advanced packaging to improve heat dissipation performance and space efficiency.