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MAXREFDES1302: Maxim 1-Wire True Wireless Stereo (TWS) Cradle and Earbuds

MAXREFDES1302

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Description

MAXREFDES1302 is a reference design for TWS application based on the Maxim 1-Wire® solution. This reference design provides power and battery management solutions for the TWS cradle and earbuds (right & left), including battery charging, battery monitoring, and power management. An OLED display is mounted on the cradle side to display earbud connection state, state-of-charge (SOC in %) and remaining capacity (CAP in mAh) of batteries of the cradle and earbuds. A serial port monitor can also be used to show such information.

On the cradle side, USB Type-C® charging is realized by the MAX77751, which integrates a 3.15A switch charger and BC1.2. Also, USB Type-C Configuration Channel (CC) detection pins of the MAX77751 enable automatic USB Type-C power source detection and input current limit configuration. The MAX17262 is used to monitor battery remaining capacity and state-of-charge of the batteries. The MAX17262 implements the Maxim ModelGauge™ m5 EZ algorithm and features internal current measurement for up to 3.1A pulse currents. The MAX17224 is an ultra-low quiescent current boost DC-DC converter with a 225mA/0.5A/1A peak inductor current limit and True Shutdown™. The MAX38640 is nanoPower family of ultra-low 330nA quiescent current buck (step-down) DC-DC converters that operate from 1.8V to 5.5V input voltage and support load currents of up to 175mA with peak efficiency of 96%. While in shutdown, there is only 5nA of shutdown current. The MAX32655 microcontroller is used to configure the fuel gauge, 1-Wire communication, and 1-Wire power transfer.

On the earbud side, the DS2488 provides a cost-effective solution for power transfer and communication between the TWS cradle and earbuds. The DS2488 is a low-cost simple bridge device with a single dedicated contact on each side of the bridge which enables power delivery for the battery charging, small message exchange, and the state reporting between two microcontroller-based subsystems. The battery management system for earbuds consists of the MAX77734 and MAX17262. The MAX77734 provides highly integrated battery charging and power supply solutions for the low-power applications where size and efficiency are critical. The MAX32655 on the earbud side configures the MAX77734, MAX17262, DS2488 and MAX98050. The MAX98050 is a low-power, high-performance audio codec with integrated low-latency digital filters for wireless hearables, headsets, and headphones.

Features

  • Integrated solution
  • Small size
  • Low power
  • High accuracy
  • Low cost
 

Schematic

schematic

Download the full circuit schematic.

PCB Layout

pcb-layout

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BOM

bom

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Test Results

test-results

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Parametrics

Input Type Vin(Min) Vin(Max) Iout(Max) Single/Multiple Output Vout(V) Pout(W) Isolated/Non-Isolated Topology
DC 3.1 5.2 0.01 Single 5 0.05 Non-isolated NC

Parametrics

Input Type DC
Vin(Min) 3.1
Vin(Max) 5.2
Iout(Max) 0.01
Single/Multiple Output Single
Vout(V) 5
Pout(W) 0.05
Isolated/Non-Isolated Non-isolated
Topology NC

Maxim Devices (8)

Part Number Name Product Family Order Design kits and evaluation modules
MAX77751 3.15A USB Type-C Autonomous Charger for 1-Cell Li+ Batteries Battery Management Buy Now
MAX17262 5.2µA 1-Cell Fuel Gauge with ModelGauge m5 EZ and Internal Current Sensing Battery Management Buy Now
MAX17224 400mV to 5.5V Input, nanoPower Synchronous Boost Converter with True Shutdown Switching Regulator - Switching Regulators Buy Now
MAX38640 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Switching Regulator - Switching Regulators Buy Now
DS2488 1-Wire Dual-Port Link 1-Wire Buy Now
MAX77734 Ultra-Low Power Tiny PMIC with Power Path Charger for Small Li+ and 150mA LDO Power Management ICs Buy Now
MAX98050 Low-power, High-Performance Audio CODEC Audio Buy Now
MAX32655 Low-Power, Arm Cortex-M4 Processor with FPU-Based Microcontroller and Bluetooth 5.2 MCU - Microcontroller Buy Now

Maxim Devices (8)

Part Number Product Family
Battery Management
3.15A USB Type-C Autonomous Charger for 1-Cell Li+ Batteries
Battery Management
5.2µA 1-Cell Fuel Gauge with ModelGauge m5 EZ and Internal Current Sensing
Switching Regulator - Switching Regulators
400mV to 5.5V Input, nanoPower Synchronous Boost Converter with True Shutdown
Switching Regulator - Switching Regulators
Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter
1-Wire
1-Wire Dual-Port Link
Power Management ICs
Ultra-Low Power Tiny PMIC with Power Path Charger for Small Li+ and 150mA LDO
Audio
Low-power, High-Performance Audio CODEC
MCU - Microcontroller
Low-Power, Arm Cortex-M4 Processor with FPU-Based Microcontroller and Bluetooth 5.2

Design Files (4)

Title Type Size Date
MAXREFDES1302 BOM XLSX 19KB 2021-11-25
MAXREFDES1302 PCB Layout PDF 1MB 2021-11-25
MAXREFDES1302 Schematic PDF 58KB 2021-11-25
MAXREFDES1302 Test Results PDF 1MB 2021-11-25
Date Type
2021-11-25

MAXREFDES1302 BOM

(XLSX, 19KB)

2021-11-25

MAXREFDES1302 PCB Layout

(PDF, 1MB)

2021-11-25

MAXREFDES1302 Schematic

(PDF, 58KB)

2021-11-25

MAXREFDES1302 Test Results

(PDF, 1MB)

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