SLUAAR1 july   2023 BQ24630 , BQ25170 , BQ25180 , BQ25300 , BQ25620 , BQ25730 , BQ25798

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Charge Profile and SOC vs OCV
  6. 3Thermal Runaway and Temperature Characteristics
  7. 4Applications
  8. 5Summary
  9. 6References

4 Applications

As previously mentioned, the main advantages of LiFePO4 are their thermal stability, low chances of going into thermal runaway, longer cycle life, and higher discharge current. However, due to their low energy density, LiFePO4 batteries typically take up more space compared to Li-ion batteries. This makes LiFePO4 batteries good for applications that need good thermal performance and can afford to take up more space. They are also good for applications that need a higher discharge current and/or need higher cycle life.

LiFePO4 could be a good choice for personal devices due to their safety characteristics. The designer would be less concerned about thermal runaways potentially harming their consumers. LiFePO4 batteries can also be a good choice for start up circuits due to their higher discharge currents. Furthermore, any application where cycle life is the main concern, LiFePO4 would be the better choice over Li-ion batteries.

Table 4-1 shows various TI charging designs that are compatible with Li-ion and LiFePO4 batteries. The designs provided here should satisfy a large variety of applications, there are examples of standalone designs, buck-boost, buck, and linear design and with various cell configurations. All of these designs have very good charge voltage accuracy and have thermal regulation.

Most of these designs have power path management which will automatically switch the power path from adapter to battery and vice versa. Furthermore, all of these designs provide dynamic power management (DPM) with the majority of these designs allowing the battery to supplement the system load if it becomes too much for the adapter. All of these designs also provide overcurrent and overvoltage protection.

Table 4-1 Charging Designs

BQ25798

BQ25730

BQ25620

BQ25300

BQ24630

BQ25180

BQ25170
VIN Max Rating 30 V 32 V 26 V 28 V 33 V 25 V 30 V
VIN Operating Range 3.6 – 24 V 3.5 – 26 V 3.9 – 18 V 4 – 17 V 5 – 28 V 3.0 – 5.9 V 3.0 – 6.65 V
Battery Configuration Li-ion, LiFePO4 Li-Ion, LiFePO4, NiMH, Supercap Li-ion, LiFePO4 Li-ion Li-ion, LiFePO4 Li-Ion, LiFePO4 Li-Ion, LiFePO4
Cell Configuration 1s – 4s 1s – 5s 1s 1s 1s – 7s 1s 1s
Topology Buck-Boost Buck-Boost Buck Buck Buck Linear Linear
Charge Voltage 3 to 18.8 V 1.024 to 23 V 3.5 to 4.8 V 4.1 to 4.4 V 1.8 to 26 V 3.5 V to 4.65 V 3.5 V to 4.4 V
Charge Voltage Accuracy (Over Temp) -0.25 to +0.65 % ±0.5 % ±0.5 % ±0.5 % ±0.5 % ±0.5 % ±0.5 %
Max Charge Current 5 A 16.2 A 3.5 A 3 A 10 A 1 A 0.8 A
Control Interface I2C I2C I2C Standalone Standalone I2C Standalone
Power-Path Management Yes Yes Yes No Yes Yes No
Fast Charge Timer Programmable Programmable Programmable Fixed Programmable Programmable Fixed
Package 4.0x4.0mm QFN-29 4.0x4.0mm WQFN-32 2.5x3.0mm WQFN-18 3.0x3.0mm RTE WQFN 4.0x4.0mm VQFN-24 1.6x1.1mm WCSP-8 2.0x2.0mm QFN-8
Additional Market Application Video Doorbell, Smart Home Control, Vacuum Robot Tablet, Wireless Speaker, Ventilators, Vacuum Robot Tablet, Computer Accessories, IP Camera, EPOS Wireless Speakers, Barcode Scanner, Cordless Power Tool Power Tools, Netbook, Medical Equipment TWS, Wearable, Medical, Building and Retail Automation TWS, Wearable, ePOS, Camera