TI公司的bq25871是集成了10位ADC的14V 7A電池開關(guān)充電器,輸入電壓3-14V,集成了MOSFET和電流檢測,集成的高精度ADC用來系統(tǒng)監(jiān)測,高達(dá)1MHz I2C讀和寫速度,主要用在智能手機(jī),平板電腦和有大電池容量的其它手持設(shè)備.本文介紹了bq25871主要特性,功能框圖,應(yīng)用電路以及充電器評估模塊BQ25871EVM-813主要特性,電路圖,材料清單和PCB設(shè)計圖.
The device is a 7-A battery switch charger with an integrated 10-bit ADC. The high-current battery switch charger is a 13-mΩ MOSFET with reverse current blocking designed for high efficiency and minimal voltage drop. The high-charge current capability of the device makes it ideal for smartphones, tablets, and other portable devices with large battery capacity.
The integrated 10-bit ADC can measure input voltage and current, battery voltage and current, as well as battery temperature and input connector temperature. This allows the user application to continuously monitor the power input and battery charging parameters to ensure the safety of the battery charging. The flexible OVP and OCP thresholds for VBUS, VOUT, and battery can be modified via I2C registers as the battery goes through constant current (CC) and constant voltage (CV) mode.
The I2C serial interface of the device can operate at speeds up to 1 MHz and allows access to the ADC’s measurements of the different charging parameters and also allows for flexible software control of the device. The INT pin provides instantaneous feedback to the host in case of a fault condition. I2C status registers allow the host to read the current status of all faults and events.
bq25871主要特性:
Adapter Input Voltage Range: 3 V to 14 V
Allow up to 14-V Adaptor Voltage
Highly Integrated 7-A Battery Switch
Integrated MOSFETs and Current Sensing
Low RDS(on) (13-mΩ) MOSFETs for High Current Operation
Integrated High Accuracy ADC for System Monitor
VBUS, VBAT, VOUT, VDROP Voltage
Input and Battery Current
Battery and VBUS Connector Temperature
Linear Regulation (LDO) Mode Operation
Four Linear Regulation Loops: IBUS, IBAT, VBAT and VOUT
Programmable Linear Regulation Thresholds
Programmable Safety Protections
VBUS, VOUT, and VBAT Over Voltage Protections (OVP)
IBUS and IBAT Over Current Protection (OCP)
IBUS Reverse Current Protection (RCP)
VDROP (VBUS-VOUT) OVP
VBUS Connector and Battery Thermal Protection
Thermal Shutdown
Interrupt Status Output For Host Processor Alert
Up To 1-MHz I2C Read and Write Speed
Low Battery Leakage Current in Battery Only Mode
WCSP Package for Small Footprint
圖1.bq25871功能框圖
圖2.bq25871應(yīng)用電路圖
BQ25871充電器評估模塊
This user’s guide provides detailed testing instructions for the bq25871 and bq25872 evaluation modules(EVM). Also included are descriptions of the necessary equipment, equipment setup, and procedures. Thereference documentation contains the printed-circuit board layouts, schematics, and the bill of materials(BOM).
The bq25871 evaluation module (EVM) is a complete charger module for evaluating the highly-integrated battery switch in WCSP package for 1 cell Li-Ion and Li-polymer battery in a wide range of smartphone and tablet applications.
BQ25871充電器評估模塊BQ25871EVM-813主要特性:
Input voltage range of 3V to 14V and charge current up to 7A
Highly integrated 7A battery switch and high accuracy ADC
Programmable protection and safety features
Test points for all signals available for testing purposes
Jumpers for different circuit configuration
圖3.BQ25871EVM-813充電器評估模塊外形圖
圖4.BQ25871EVM-813充電器評估模塊電路圖
BQ25871EVM-813充電器評估模塊材料清單:
圖5.BQ25871EVM-813充電器評估模塊PCB設(shè)計圖(頂層)
圖6.BQ25871EVM-813充電器評估模塊PCB設(shè)計圖(中間層1)
圖7.BQ25871EVM-813充電器評估模塊PCB設(shè)計圖(中間層2)
圖8.BQ25871EVM-813充電器評估模塊PCB設(shè)計圖(底層)
圖9.BQ25871EVM-813充電器評估模塊PCB設(shè)計圖(頂層裝配)
圖10.BQ25871EVM-813充電器評估模塊PCB設(shè)計圖(底層裝配)
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