開關模式降壓充電器MAX77860解決方案

Maxim公司的MAX77860是USB Type-C 3A開關模式降壓充電器，集成了CC檢測和BC1.2檢測和ADC.該充電器集成了兩個開關，使用小型電感和電容尺寸，可編程充電電流，非常適合用在手持設備如智能手機，IoT設備和其它鋰電池電子設備。充電器具有單輸入，可工作于USB和高壓適配器。支持BC 1.2標準下的USB Type-C CC檢測，芯片還集成了電源通路開關，USB-OTG輸出提供真負載斷開功能，并可調整輸出電流限制，而輸入電流限制高達4.0A，單電池充電電流高達3.15A;當配置在反向升壓模式，器件就不需要另外電感器。高達14V保護，充電器具有D+/D-充電檢測，CC，CV和芯片溫度控制，主-從充電功能，高達6A充電電流，支持USB-OTG反向升壓，高達1.5A電流限制。本文介紹了MAX77860主要優勢和特性，框圖和功能框圖，典型應用電路圖以及評估板MAX77860 EVK主要特性，電路圖，建立圖和材料清單。

The MAX77860 is a high-performance single input switch mode charger that features USB Type-C CC detection capability in addition to reverse boost capability and a Safe-out LDO.

This switched-mode battery charger with two integrated switches， provides small inductor and capacitor sizes， programmable battery charging current， and is ideally suited for portable devices such as smartphones， IoT devices， and other Li-ion battery powered electronics. The charger features a single input， which works for both USB and high voltage adapters. It supports USB Type-C CC detection under BC 1.2 specification， and the power-path switch is integrated in the chip. All MAX77860 blocks connected to the adapter/USB pin are protected from input overvoltage events up to 14V. The USB-OTG output provides true-load disconnect and is protected by an adjustable output current limit. It has an input current limit up to 4.0A， and can charge a single-cell battery up to 3.15A. When config-ured in reverse-boost mode， the IC requires no additional inductors to power USB-OTG accessories. The switching charger is designed with a special CC， CV， and die tem-perature regulation algorithm， as well as I2C programma-ble settings to accommodate a wide range of battery sizes and system loads. The on-chip ADC can help monitor the charging input voltage/current， battery voltage， charging/discharging current， and the battery temperature.

The MAX77860 communicates through an I2C 3.0 com-patible serial interface consisting of a bidirectional serial data line （SDA） and a serial clock line （SCL）。 The IC is available in a 3.9mm x 4.0mm， 81-bump （9 x 9 array）， 0.4mm pitch， wafer-level package （WLP）。

MAX77860主要優勢和特性：

● Single-Input Switch Mode Charger

? Up to 14V Protection

? 4.0V to 13.5V Input Operating Range

? Switching Charger with D+/D- Charger Detection

? Up to 4.0A Input Current Limit with Adaptive Input Current Limit （AICL）

? Up to 3.15A Battery Charging Current Limit

? Optional External Sense Resistor

? CC， CV， and Die Temperature Control

? Supports USB-OTG Reverse Boost， up to 1.5A Current Limit

? Master-Slave Charging Capability， up to 6A Charge Current

? Integrated Battery True-Disconnect FET

? Rated up to 9ARMS， Discharge Current Limit （Programmable）

● USB Type-C Detection

? Integrated VCONN Switch

? CC Pin

? D+/D- Detection for USB HVDCP

? BC 1.2 Support

● One Safeout LDO

● I2C-Compatible Interface

MAX77860應用：

● USB Type-C Charging for 1S Li-ion Applications

● Mobile Point-of-Sale Devices

● Portable Medical Equipment

● Portable Industrial Equipment

圖1.MAX77860簡化框圖

圖2.MAX77860功能框圖

圖3.MAX77860典型應用電路圖

評估板MAX77860 EVK

The MAX77860 evaluation system （EV system） is a fully assembled and tested surface-mount printed circuit board （PCB） that evaluates the single input switched-mode battery charger featuring USB Type-C CC detection and charging capability in addition to reverse boost capability and a safest LDO.

The MAX77860 EV system includes the integrated circuit （IC） evaluation board with an integrated I2C interface and a MINIQUSB communication device. Windows? based graphical user interface （GUI） software is available for use with the EV system and can be downloaded from the MAX77860 product page on the Maxim website. A Windows 7 or newer operating system is required to use the EV kit GUI software.