Solutions for Li-ion Battery Systems
Solutions for Applications powered by Li-ion Batteries
For IoT and Wearable applications requiring low power consumption
Applications powered by Li-ion batteries are hugely popular in the market today. Whether it be a piece of wearable tech, a new IoT device or a tablet computer, Li-Ion batteries provide the power for many of the products we use every day.
The system requirements and size of battery will vary, but the principals of any Li-Ion design remain the same. Designers will always need small, efficient solutions that can operate with low power consumption to maximise battery life.
Torex offers a variety of different solutions for single cell Li-Ion based systems as outlined in the article below
Application Example: Step-Down DC/DC Converter For MCU
Using a single Li-ion Battery to power a simple system
Key system requirements:
- Implement discharge prevention during shipment and have an effective countermeasure for a system freeze
- Ensure highest efficiency with ultra-low power consumption for the main power circuitry
- Must have low noise output from the LDO for the RF and sensor rails
Recommended Solution:
|
Circuit Block |
Torex Series |
Key Features |
|---|---|---|
| (1) Battery Charger | XC6803/08 | CC/CV charging, CC=~280mA/40mA |
| (2) Push Button SW | XC6194 | ISTB=1nA, ship mode (OFF during transit) and to reset system freeze state, 1A |
| (3) Step-down DC/DC | XCL232 | Iq=200nA, Integrated coil, PFM, 150mA, Low EMI |
| XC9276 | Iq=200nA, PFM, 150mA, VSET pin | |
| XCL202 | Integrated coil, PWM/PFM, 1.2MHz, 400mA, Ultra-low EMI | |
| (4) LDO | XC6241 | Iq=0.6μA, PSRR=60dB, GO Mode, 150mA |
| (5) RESET IC | XC6136 | Iq=100nA class Ultra Low Iq |
Operation and purpose:
(2) Push button load SW with built-in ship-mode function
- Our XC6194 is a simple solution for disconnecting the system during shipment (ship-mode). It can also be used to RESET the whole system in the event of a software freeze event.
(3) Ultra low Iq Step-down DC/DC for MCU
- Ultra-low quiescent current DC/DC are ideal for this application. Our XCL232 and XC9276 offer very low Iq (200nA typ.) and the XC9276 has an additional VSET function which allows the designer to select a lower VOUT for when the MCU is sleeping.
- To further reduce the EMI our XCL202 Micro DC/DC provides a compact solution, with lower switching frequency, which is ideal for noise sensitive supply rails required for sensors and RF circuits.
(4) LDO for RF / Sensor
- The Green Operation (GO) function changes the operation of the LDO automatically between Low Power and High Speed mode, which ensure both low quiescent current and high-speed operation with fast transient response and low output noise.
Application Example: Directly Powering The MCU
Using a single Li-ion Battery to power a system with multiple higher current rails.
Key system requirements:
- Ensure highest efficiency with ultra-low power consumption for the main power circuitry.
- Minimise EMI with careful selection of small highly integrated solutions.
- Allow for automatic switching between the main 5V supply and the Li-ion battery when 5V removed.
- Implement discharge prevention during shipment and have an effective countermeasure for a system freeze
Recommended Solution:
|
Circuit Block |
Torex Series |
Key Features |
|---|---|---|
| (6) Battery Charger | XC6803/04 | CC/CV charging, CC=~280mA/800mA |
| (7) Ideal Diode | XC8110/11 | VF=20mV, 500mA (XC8110) or 1A (XC8111) |
| (8) Step-down DC/DC | XCL201/02 | Integrated coil, PWM/PFM, 1.2MHz, 400mA, Ultra-low EMI |
| XCL205/06 | Integrated coil, PWM/PFM, 3MHz, 600mA | |
| XCL211/12 | Integrated coil, PWM/PFM, 2.4MHz, 2A | |
| (9) Reboot Controller | XC6190 | Output reset signal by holding SW1 and SW2 low 'L' |
Operation and purpose:
(7) Load switch with Ideal Diode function
- The circuit above automatically switches between the main 5V input rail and the Li battery output using the XC8110/11 ideal diode in an OR circuit configuration.
- Adding an additional Nch FET will implement a shipping-mode function, whereby the system can be disconnected from the battery when the product shipped from the factory to the end user. The system can be reconnected when the user pushes the power button.
(8) Step-down DC/DC for MPU / Memory / FPGA at point of load (POL)
- Stable operation with small size and low EMI can be realised by placing a Micro DC/DC with integrated coil close to the POL.
(9) Push button Reboot controller:
- Adding a push button reboot IC that can reboot the system by pressing and holding the external switch as a countermeasure for system freezes. The switch can also be shared with the MCU for other functions.