Lithium battery protection board technical indicators, lithium battery protection solutions

2021-09-06 08:57:22 0

Lithium battery protection board technical indicators, lithium battery protection solutions. In layman's terms, lithium batteries generally have a corresponding lithium battery protection board to assist their work. The role of the lithium battery protection board is to avoid a series of unexpected situations such as short circuits, so the parameter requirements of the protection board are also extremely precise.

Technical indicators of lithium battery protection board

1. Voltage protection capability

Overcharge protection: The lithium battery protection board must have the ability to prevent the battery cell voltage from exceeding the preset value. Over-discharge protection: The protection board must have the ability to prevent the battery cell voltage from falling below the preset value.

2. Current capability

As a safety protection device for lithium batteries, the protection board must not only work reliably within the normal operating current range of the equipment, but also be able to act quickly when the battery is accidentally short-circuited or over-current, so that the batteries are protected.

3. On-resistance

Due to the high operating frequency of communication equipment, the low bit error rate required for data transmission, and the steep rising and falling edges of the pulse train, the current output capability and voltage stability of the battery are required to be high, so the MOS switch of the protection board is turned on The time resistance should be small. The single-cell battery protection board is usually less than 70mΩ. If it is too large, it will cause the communication equipment to work abnormally.

4. Self-consumption current

Definition: The working voltage of the IC is 3.6V. Under no-load conditions, the working current flowing through the protection IC is generally very small. The self-consumption current of the protection board directly affects the standby time of the lithium battery, and the self-consumption current of the protection board is usually specified Less than 10 microamperes.

5. Mechanical properties, temperature adaptability, antistatic ability

The lithium battery protection board must be able to pass the vibration and impact tests specified by the national standard; the protection board can work safely at -40 to 85 degrees, and can withstand the non-contact ESD electrostatic test of ±15KV.

Lithium battery protection solution

In recent years, there has been a trend in the industry to package several chips together to improve integration and reduce the area of the final solution. The lithium battery protection market is no exception. The two lithium battery protection schemes A and B seem to integrate two chips into one chip, but in fact, the internal controller IC and switch tube chip of the package are still separate. They come from different manufacturers. This scheme only combines The two are sealed together, commonly known as "two cores in one".

The XB430X series of chips have a very high degree of integration, which not only integrates the traditional control IC and switch tube, but also integrates R1 and R2 in the schematic diagram 1 into the same chip. The integrated chip is very small, and the smallest can be packaged in the common SOT23-5L package on the market. The internal resistance of the switch tube of this chip series is extremely low, and the minimum internal resistance can reach below 40mΩ, which is equivalent to the internal resistance of the best switch tube on the market. When using the smallest package SOT23-5L, the continuous charging and discharging current can reach 2.5 amps without heat dissipation problems. If the continuous charge and discharge current is greater than 2.5A, it is recommended to use the SOP8 packaged product in the XB430X series.

XB430X has all the protection functions in the traditional protection scheme: overcharge protection, overdischarge protection, overcurrent protection and short circuit protection. Not only that, because the control IC and the switch tube are integrated in the same chip, the control IC can detect the temperature of the switch tube chip at any time. When the battery is used in a high temperature environment for a long time, or the current exceeds the normal charge and discharge current during charging and discharging, but does not reach the overcurrent protection threshold and other reasons, the chip temperature is too high, the overtemperature protection function will be activated to protect the chip and Battery. In addition, the built-in switch tube has an ESD protection function, which can greatly improve the yield of the protection board and the battery during the processing.

The XB430X internal control IC and switch tube come from the same production process and the same manufacturer. The packaging uses the most mature and universal packaging form, so the consistent performance is much higher than the traditional solution, the "two-core in one" solution, and the positive electrode protection solution.

Using XB4301 series chips, only two components are required to complete the final battery protection program. Compared with the five components of the traditional program, the production capacity and efficiency of each placement machine can be increased by 2.5 times. Compared with traditional solutions, lithium battery protection board manufacturers not only do not need to buy resistors and switch tube chips, which simplifies the resource chain, but also reduces the pads of two resistors and 8 solder joints of the switch tube when making the protection board, thus greatly The production cost of the protection board is reduced.

Summary: As the core component of the battery system, the lithium battery protection board is the bridge between the power battery and the outside world, and determines the utilization rate of the battery. Its performance is very important to the cost and safety of the battery. The components of the lithium battery protection board bear an important mission for the safety of the battery. Its performance and quality are also an important factor of the performance and quality of the battery pack.