Low-power, wearable, highly integrated battery charging and power solution - MAX77650/MAX77651

Maxim's MAX77650/MAX77651 are highly integrated, battery-powered charging and power solutions for low-power wearables with a SIMO buck-boost regulator with three outputs and programmable voltage regulation from 3.6-4.6V. The programmable current is 0.375-45mA, which is mainly used in Bluetooth headsets, fitness and activity monitors, and the device and the Internet of Things (IoT). This article introduces the advantages and main features of the MAX7765, functional block diagrams and application circuits, and the evaluation of the MAX77650/MAX77651. Board EVK main features, component map, circuit diagram, bill of materials and PCB design.

The MAX77650/MAX77651 provide highly-integrated battery charging and power supply soluTIons for low-power wearable applicaTIons where size and efficiency are criTIcal. Both devices feature a SIMO buck-boost regulator that provides three independently programmable power rails from a single inductor to minimize total A highly configurable linear charger supports a wide range of Li+ battery capacities and includes battery temperature monitoring for additional safety (JEITA). A highly configurable linear charger supports for audio and other noise-sensitive applications.

The devices include other features such as current sinks for driving LED indicators and an analog multiplexer that switches several internal voltage and current signals to an external node for monitoring with an external ADC. A bidirectional I2C interface allows for configuring and checking the status of the devices An internal on/off controller provides a controlled startup sequence for the regulators and provides supervisory functionality when the devices are on. Numerous factory programmable options allow the device to be tailored for many applications, enabling faster time to market.

Advantages and Key Features of the MAX7765:

Highly IntegratedSmart Power SelectorTM Li+/Li-Poly Charger
3 Output, Single-Inductor Multiple-Output (SIMO) Buck-Boost Regulator
150mA LDO
3-Channel Current Sink Driver
Analog MUX Output for Power Monitoring
Low Power0.3μA Standby Current
5.6μA Operating Current (3 SIMO Channels + LDO)
Charger Optimized for Small Battery SizeProgrammable Fast-Charge Current from 7.5mA to 300mA
Programmable Battery Regulation Voltage from 3.6V to 4.6V
Programmable Termination Current from 0.375mA to 45mA
JEITA Battery Temperature Monitors Adjust Charge Current and Battery Regulation Voltage for Safe Charging
Flexible and ConfigurableI2C Compatible Interface and GPIO
Factory OTP Options Available
Small Size2.75mm x 2.15mm x 0.7mm WLP Package
30-Bump, 0.4mm-Pitch WLP, 6x5 Array
Small Total Solution Size (19.2mm2)

MAX7765 application:

Bluetooth Headphones/Hearables
Fitness, Health, and Activity Monitors
Portable Devices
Internet of Things (IoT)

Figure 1. SIM7765 simplified functional block diagram

Figure 2. Typical application circuit diagram of the MAX7765

Evaluation Kit for the MAX77650/MAX77651 EVK

The MAX77650/MAX77651 evaluation kit (EV kit) is a fully assembled and tested printed circuit board (PCB) that demonstrates the MAX77650/MAX77651. The EV kit allows for easy evaluation of the various MAX77650/MAX77651 features, including the SIMO buck-boost Regulator, linear regulator, analog multiplexer, smart battery charger, on/off controller, and I2C interface.

The MAX77650 and MAX77651 EV kits are identical aside from the device (U1), silkscreen, and two resistive dividers at the SIMO outputs. The MAX77650/ MAX77651 devices themselves have different output voltage ranges for the SIMO buck-boost regulator. Consult the device data Sheet for more information.

Windows®-based software provides a user-friendly graphical interface as well as a detailed register-based interface to exercise the features of the MAX77650/MAX77651.

Key features of the MAX77650/MAX77651 evaluation board EVK:

Easy to Use
GUI Drives I2C Interface
On-Board Battery Ammeter
On-Board Thermistor
On-Key Options
RGB LED Cluster
Assembled and Fully Tested
Emulates System Loading
On-Board Electronic Loads
Electronic Loads have steady-state, transient, and random modes
Demonstrates End-to-End Analog Multiplexer Implementation
On-Board ADC
Evaluates Both Push-Button and Slider-Switch On-Key Options

Figure 3. EVK outline drawing of the MAX77650 evaluation board

Figure 4. EVK top component distribution for the MAX77650 EV kit

Figure 5. EVK underlying component distribution for the MAX77650 EV kit

Figure 6. EVK circuit diagram of the MAX77650 evaluation board (1)

Figure 7. EVK circuit diagram for the MAX77650 evaluation board (2)

Figure 8. EVK circuit diagram of the MAX77650 evaluation board (3)

Figure 9. EVK circuit diagram for the MAX77650 evaluation board (4)

Figure 10. EVK circuit diagram for the MAX77650 evaluation board (5)
MAX77650 Evaluation Board EVK Bill of Materials (BOM):

Figure 11. EVK PCB Design for the MAX77650 Evaluation Board (1)

Figure 12. EVK PCB Design for the MAX77650 Evaluation Board (2)

Figure 13. EVK PCB Design for the MAX77650 Evaluation Board (3)

Figure 14. EVK PCB Design for the MAX77650 Evaluation Board (4)

Figure 15. EVK PCB Design for the MAX77650 Evaluation Board (5)

Figure 16. EVK PCB Design for the MAX77650 Evaluation Board (6)

Timer Switch Socket

Digital Timer Switch Sockets,Digital Timer Outlet,Plug-in Time Controller,Plug In Timers,Sockets with Timers

NINGBO COWELL ELECTRONICS & TECHNOLOGY CO., LTD , https://www.cowellsockets.com