Other Parts Discussed in Thread: BQ25120A,
A wearable device sing BQ51003 (wireless) and BQ25120a are incorporated. We have made the schematic and will be making the Gerber. Would like to get it reviewed.
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Hello
I am reviewing the circuit, should have update later today.
Do you have a data sheet or info on the RX coil?
WR222230-26M8-G from TDK
or from china local link - www.aliexpress.com/.../4000086798457.html
Hello
The BQ51003 section looks OK, may need some tuning of values. The Coil is a good one and we have used it on some reference designs.
Hello,
For the BQ25120a section, PMID should NOT be grounded. This is the unregulated supply used to charge the battery as well as input for the DCDC. Connect at least 4.7uF to PMID.
TS should have a voltage divider pulled up to VIN. Please look at page 26 on the datasheet for the equations.
/MR will need a pushbuton to exit shipmode unless you only exit shipmode using VIN plugin.
/CD will need to be controlled by a GPIO for VIN present and absent scenario.
The required inductor for the DCDC is 2.2uH not 150nH. Please change this.
Ensure SCL and SDA are pulled up to VSYS.
Additionally, note that the DCDC on the BQ25120A defaults to 1.8V on startup and can be changed to 3.3V later.
Also, set the default for ISET, IPRETERM and ILIM with proper resistors. The current values are outside the limits. Page 23 and 24 have suggested values.