Lithium Battery Protect Design
In order to prevent affecting the battery life of lithium batteries in the abnormal state of the overcharge, over-discharge, over-current, typically by a lithium battery protection device to prevent damage of the abnormal state of the battery. More widely lithium battery applications, from portable devices such as mobile phones, MP3, MP4, GPS, toys to the need to continue to save gas meter data, its market capacity has reached hundreds of millions of only a month.
The lithium battery protection circuit of the device shown in Figure 1, mainly by the battery protection control IC and an external discharge switch M1 and a charging switch M2. When the P + / P-end connected to the charger, the battery normal charge, M1, M2 in the conduction state; when the control IC to detect charging abnormal, M2 is off to terminate charging. When the P + / P-end connected load, battery discharge normal, M1, M2 are turned on; when the control IC to detect abnormal discharge off the M1 termination of the discharge.
Several existing lithium battery protection program
Figure 2 is based on the principle of the lithium battery protection design of a common lithium battery protection board. In SOT23-6L package control IC package SOP8 double switch M1, M2. Vary due to the manufacturing process and manufacturing process of the switch control IC , Figure 2, two chip made from a different process, usually these two chips is also provided by the chip manufacturers.
In recent years, the industry has a few chips packaged together to improve integration, reduce the trend of the last program area. Lithium battery protection market is no exception. A and B of Figure 3, two lithium battery protection looks in Figure 2 two chip integrated on a single chip, but in fact its package internal controller IC and the switch chip is still separate and different from manufacturers, the program is only two together sealed together, commonly known as "core unity.
Two internal chip actual still from different vendors, the shape can not be a good match, resulting in the final package shapes, in many cases, can not adopt a common package. The relatively large size of this package, they can not save external components, so this "core one" program actually Province, not too much space. In terms of cost, although the cost of two packages is reduced to the cost of a package, but this package is usually relatively large, some not generic package, some in order to reduce the package size, chip stacking package in the form, so traditional compared to the two-chip solution, the cost advantage is not obvious.
Figure 4 is a true controller chip and switch chip integrated single-chip solutions in the same wafer. Switch tube in the schematic diagram of the traditional scheme 1 is an N-type tubes, and between the B-and P-In Figure 1, commonly known as cathodic protection. The program in Figure 4, for technical reasons, the switching tube can only be changed to a P-type tube, connected between the B + and P +, commonly known as the positive electrode protection. Complete program of protection board with this chip, users need to be replaced in the detection protection board test device and philosophy. Although reduced packaging costs, but the cost of the chip has not been reduced, there is no real cost advantage in the the mature traditional program with a large quantity competition. In contrast the the cathode protection concept incompatible with the traditional program became the promotion process huge obstacles.
Although the above "core one" program and Single-chip cathode protection program to the user in the size and cost of the program has brought certain advantages, but the advantage is still not clear. These programs at the same time bring some drawbacks, therefore, in the process with the the mature traditional program competitive customers, eventually only to reduce the margin space to compete on price. Because the truly original cost of these programs and there is no obvious advantage, control IC and the switch chip price cuts as the traditional program, the program of these two core one "or positive protection program has not been able to shake the market domination of the traditional program position.
Market in recent years there have been many ups switch tube chip manufacturers, in order to reduce costs, the package originally hit gold wire into a play copper the switch tube nor with ESD protection. Although these products and brand performance switch compared to some differences, but because of the cost advantage quickly seize the secondary market, but also for the traditional program with two cores one "and cathode protection program of competition in the market The win made a great contribution.
Fully integrated lithium battery protection program
The SyChip Microelectronics patent through independent research and development of a number of devices and circuits combined with unique technology, the control IC switch tube integrated on the same chip, the introduction of the world's smallest lithium battery the protection program XB430X products. This series of products using traditional N-type switch, consistent with the principle of cathodic protection of traditional programs, the protection board manufacturer or the manufacturer of lithium batteries do not need to replace any test equipment or philosophy. The series chip itself is a lithium battery protection program without the need for any external components can be realized lithium battery protection function. In order to prevent the noise of the VCC line, it is recommended in when using XB430X series chip between VCC and the negative terminal of the battery connected to a capacitor, as shown in Figure 5.
XB430X series chip integration is very high, not only to the traditional control IC and the switch integration, and the principle of Figure 1, R1, R2 is also integrated into the same chip. Integrated chip is very small, the smallest market generic SOT23-5L package. The chip series switch resistance is very low minimum internal resistance of up to 40m? With the best available switch resistance quite. When using the smallest package SOT23-5L, continuous charge and discharge current up to 2.5 amps instead of a heat problem. Continuing to charge and discharge current greater than 2.5 amps, it is recommended that SOP8 package products the XB430X series.
XB430X have all the protection features of the traditional protection programs: overcharge protection, over-discharge protection, overcurrent and short circuit protection. Moreover, due to the control IC with the switch tube integrated on the same chip, readily detect switch chip temperature control IC. A result of long-term use in high-temperature environments, or charge-discharge current exceeds the normal charge and discharge current when the battery reasons, but did not reach the overcurrent protection threshold when the chip temperature is too high, you will start over temperature protection, in order to protect the chip and battery supplier. In addition, the built-in switch tube with ESD protection, can significantly improve the yield of protection board and battery in the process.
XB430X internal control IC and switch tube from the same production process, the same vendor, package selection of the most mature and versatile package, thus consistent performance than traditional programs, two cores, one "program, the positive protection program should be much higher.
XB4301 series chip, the completion of the final battery protection program only two components (see Figure 5), compared with the five components of the traditional program, the capacity and efficiency of each placement machine can be increased to 2.5 times. Compared with the traditional program, protection board manufacturers not to buy the resistors and switch chip, to streamline the resource chain, but also in the production of the protective plate to reduce the two resistor pads and switch 8 welds, thereby greatly reducing the production costs of the protective plate.
The lithium battery protection circuit of the device shown in Figure 1, mainly by the battery protection control IC and an external discharge switch M1 and a charging switch M2. When the P + / P-end connected to the charger, the battery normal charge, M1, M2 in the conduction state; when the control IC to detect charging abnormal, M2 is off to terminate charging. When the P + / P-end connected load, battery discharge normal, M1, M2 are turned on; when the control IC to detect abnormal discharge off the M1 termination of the discharge.
Several existing lithium battery protection program
Figure 2 is based on the principle of the lithium battery protection design of a common lithium battery protection board. In SOT23-6L package control IC package SOP8 double switch M1, M2. Vary due to the manufacturing process and manufacturing process of the switch control IC , Figure 2, two chip made from a different process, usually these two chips is also provided by the chip manufacturers.
In recent years, the industry has a few chips packaged together to improve integration, reduce the trend of the last program area. Lithium battery protection market is no exception. A and B of Figure 3, two lithium battery protection looks in Figure 2 two chip integrated on a single chip, but in fact its package internal controller IC and the switch chip is still separate and different from manufacturers, the program is only two together sealed together, commonly known as "core unity.
Two internal chip actual still from different vendors, the shape can not be a good match, resulting in the final package shapes, in many cases, can not adopt a common package. The relatively large size of this package, they can not save external components, so this "core one" program actually Province, not too much space. In terms of cost, although the cost of two packages is reduced to the cost of a package, but this package is usually relatively large, some not generic package, some in order to reduce the package size, chip stacking package in the form, so traditional compared to the two-chip solution, the cost advantage is not obvious.
Figure 4 is a true controller chip and switch chip integrated single-chip solutions in the same wafer. Switch tube in the schematic diagram of the traditional scheme 1 is an N-type tubes, and between the B-and P-In Figure 1, commonly known as cathodic protection. The program in Figure 4, for technical reasons, the switching tube can only be changed to a P-type tube, connected between the B + and P +, commonly known as the positive electrode protection. Complete program of protection board with this chip, users need to be replaced in the detection protection board test device and philosophy. Although reduced packaging costs, but the cost of the chip has not been reduced, there is no real cost advantage in the the mature traditional program with a large quantity competition. In contrast the the cathode protection concept incompatible with the traditional program became the promotion process huge obstacles.
Although the above "core one" program and Single-chip cathode protection program to the user in the size and cost of the program has brought certain advantages, but the advantage is still not clear. These programs at the same time bring some drawbacks, therefore, in the process with the the mature traditional program competitive customers, eventually only to reduce the margin space to compete on price. Because the truly original cost of these programs and there is no obvious advantage, control IC and the switch chip price cuts as the traditional program, the program of these two core one "or positive protection program has not been able to shake the market domination of the traditional program position.
Market in recent years there have been many ups switch tube chip manufacturers, in order to reduce costs, the package originally hit gold wire into a play copper the switch tube nor with ESD protection. Although these products and brand performance switch compared to some differences, but because of the cost advantage quickly seize the secondary market, but also for the traditional program with two cores one "and cathode protection program of competition in the market The win made a great contribution.
Fully integrated lithium battery protection program
The SyChip Microelectronics patent through independent research and development of a number of devices and circuits combined with unique technology, the control IC switch tube integrated on the same chip, the introduction of the world's smallest lithium battery the protection program XB430X products. This series of products using traditional N-type switch, consistent with the principle of cathodic protection of traditional programs, the protection board manufacturer or the manufacturer of lithium batteries do not need to replace any test equipment or philosophy. The series chip itself is a lithium battery protection program without the need for any external components can be realized lithium battery protection function. In order to prevent the noise of the VCC line, it is recommended in when using XB430X series chip between VCC and the negative terminal of the battery connected to a capacitor, as shown in Figure 5.
XB430X series chip integration is very high, not only to the traditional control IC and the switch integration, and the principle of Figure 1, R1, R2 is also integrated into the same chip. Integrated chip is very small, the smallest market generic SOT23-5L package. The chip series switch resistance is very low minimum internal resistance of up to 40m? With the best available switch resistance quite. When using the smallest package SOT23-5L, continuous charge and discharge current up to 2.5 amps instead of a heat problem. Continuing to charge and discharge current greater than 2.5 amps, it is recommended that SOP8 package products the XB430X series.
XB430X have all the protection features of the traditional protection programs: overcharge protection, over-discharge protection, overcurrent and short circuit protection. Moreover, due to the control IC with the switch tube integrated on the same chip, readily detect switch chip temperature control IC. A result of long-term use in high-temperature environments, or charge-discharge current exceeds the normal charge and discharge current when the battery reasons, but did not reach the overcurrent protection threshold when the chip temperature is too high, you will start over temperature protection, in order to protect the chip and battery supplier. In addition, the built-in switch tube with ESD protection, can significantly improve the yield of protection board and battery in the process.
XB430X internal control IC and switch tube from the same production process, the same vendor, package selection of the most mature and versatile package, thus consistent performance than traditional programs, two cores, one "program, the positive protection program should be much higher.
XB4301 series chip, the completion of the final battery protection program only two components (see Figure 5), compared with the five components of the traditional program, the capacity and efficiency of each placement machine can be increased to 2.5 times. Compared with the traditional program, protection board manufacturers not to buy the resistors and switch chip, to streamline the resource chain, but also in the production of the protective plate to reduce the two resistor pads and switch 8 welds, thereby greatly reducing the production costs of the protective plate.
