TI公司的bq25703A是帶有系統電源監視器和處理器熱監視器的I2C多種化學電池升壓-降壓充電控制器,具有低元件數量和高效率的優勢,可從各種輸入源對1-4顆電池充電,輸入電壓3.5V-24V,支持USB2.0, USB 3.0, USB 3.1 (Type C)和USB_PD輸入電流設定,降壓和升壓工作無縫轉換.輸出電流高達6.35A,可編程開關頻率800kHz或1.2MHz,充電電壓±0.5%,輸入/充電電流±2%,輸入/充電電流監視±2%,電源監視±5%.主要用在無人機,藍牙揚聲器, IP照相機,可拆電源,平板電腦和電源組,工業和醫療設備和帶可充電電池的手持設備.本文介紹了bq25703A主要特性,功能框圖,典型應用電路圖以及評估模塊bq2570x EVM (bq25700AEVM-732和bq25703AEVM-732)主要特性,電路圖,材料清單和PCB裝配圖.

The bq25703A is a synchronous NVDC battery buck-boost charge controller, offering low component count, high efficiency solution for space-constraint, multi-chemistry battery charging applications.

The NVDC-1 configuration allows the system to be regulated at battery voltage, but not drop below system minimum voltage. The system keeps operating even when the battery is completely discharged or removed. When load power exceeds input source rating, the battery goes into supplement mode and prevents the input source from being overloaded.

The bq25703A charges battery from a wide range of input sources including USB adapter, high voltage USB PD sources and traditional adapters.During power up, the charger sets converter to buck, boost or buck-boost configuration based on input source and battery conditions. The charger automatically transits among buck, boost and buck-boost configuration without host control.

In the absence of an input source, the bq25703A supports On-the-Go (OTG) function from 1- to 4-cell battery to generate 4.48 V to 20.8 V on VBUS. During OTG mode, the charger regulates output voltage and output current.

The bq25703A monitors adapter current, battery current and system power. The flexibly programmed PROCHOT output goes directly to CPU for throttle back when needed.

bq25703A主要特性:

Charge 1- to 4-Cell Battery From Wide Range of Input Sources
3.5-V to 24-V Input Operating Voltage
Supports USB2.0, USB 3.0, USB 3.1 (Type C), and USB_PD Input Current Settings
Seamless Transition Between Buck and Boost Operation
Input Current and Voltage Regulation (IDPM and VDPM) Against Source Overload
Power/Current Monitor for CPU Throttling
Comprehensive PROCHOT Profile, IMVP8 Compliant
Input and Battery Current Monitor
System Power Monitor, IMVP8 Compliant
Narrow-VDC (NVDC) Power Path Management
Instant-On With No Battery or Deeply Discharged Battery
Battery Supplements System When Adapter is Fully-Loaded
Ideal Diode Operation in Supplement Mode
Power Up USB Port From Battery (USB OTG)
Output 4.48-V to 20.8-V Compatible With USB PD
Output Current Limit up to 6.35 A
800-kHz or 1.2-MHz Programmable Switching frequency for 1-μH to 2.2-μH Low Profile Inductor
Host Control Interface for Flexible System Configuration
I2C (bq25703A) Port for Optimal System Performance and Status Reporting
Hardware Pin to Set Input Current Limit Without EC Control
High Accuracy Regulation and Monitor
±0.5% Charge Voltage Regulation
±2% Input/Charge Current Regulation
±2% Input/Charge Current Monitor
±5% Power Monitor
Safety
Thermal Shutdown
Input, System, Battery Overvoltage Protection
MOSFET Inductor Overcurrent Protection
Low Battery Quiescent Current
Input Current Optimizer (ICO) to Extract Max Input Power
Charge Any Battery Chemistry: Li+, LiFePO4, NiCd, NiMH, Lead Acid
Package: 32-Pin 4 × 4 WQFN
bq25703A應用:
? Drones, Bluetooth Speakers, IP Cameras,Detachable, and Tablet PCs and Power Bank
? Industrial and Medical Equipment
? Portable Equipment With Rechargeable Batteries

圖1.bq25703A功能框圖

圖2. bq25703A典型應用電路圖

評估模塊bq2570x EVM(bq25700AEVM-732和bq25703AEVM-732)

The bq25700AEVM-732 and bq25703AEVM-732 evaluation modules (EVM) are SMBus or I2C-controlledNVDC-1 buck boost charger. The input voltage range is between 3.5 V and 24 V, with a programmableoutput of 1–4 cells and a charge output current range of 64 mA to 8.128 A. This EVM does not include theEV2400 interface device; the EV2400 must be ordered separately to evaluate the bq2570x EVM.

The bq2570x evaluation modules are complete charger modules for evaluating an SMBUS or I2Ccontrolledbuck boost charge using the bq2570x devices.The bq2570x EVM does not include the EV2400 interface board. To evaluate the bq2570x EVM, order anEV2400 interface board separately.

The bq2570x is a synchronous NVDC-1 battery buck boost charge controller, offering a low componentcount, high efficiency solution for space-constrained, multi-chemistry battery charging applications.

The NVDC-1 configuration allows the system to be regulated at the battery voltage, but not drop below thesystem minimum voltage. The system keeps operating even when the battery is completely discharged orremoved. When load power exceeds the input source rating, the battery supplement mode prevents theinput source from being overloaded.The bq2570x charges the battery from a wide range of input sources including a 5-V USB adapter to ahigh-voltage USB PD source and traditional adapters.

During power up, the charger sets the converter to buck, boost, or buck-boost configuration based on theinput source and battery conditions. During the charging cycle, the charger automatically transits amongbuck, boost, and buck-boost configuration without host control.

The bq2570x monitors adapter current, battery current, and system power. The flexibly programmedPROCHOT output goes directly to the CPU for throttle back, when needed.