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verify battery charging circuit and recommend any needed changes, how would i wi...
2y
To verify your battery charging circuit and integrate the TPS61221 boost converter for powering the OLED display, we'll first review the critical components and nets related to charging and power distribution. Your project includes the BQ24095DGQR for charging management and a TPS61221DCKR boost converter to elevate the battery voltage for peripherals requiring higher voltages.
Battery Charging Circuit Review
- Battery Charging IC (IC3 - BQ24095DGQR): Connected to the battery (BT1), USB port (J1), and various passive components (R9, R10, D1) for charging control.
- Battery (BT1 - VL-2330_HFN): Connected via net
18d31f0397240630c649f04d09580c08for charging and neta4496bdc8124362bce8f45f6cb920116for grounding. - Charge Status & Power Good (D1 & IC3’s ~PG pin): D1 connected to IC3's ~PG pin indicates charging status.
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Ensure Proper Feedback Network for BQ24095DGQR: The BQ24095DGQR should have a proper feedback network, including ISET to adjust charge current and PRETERM to set the charge termination threshold. Check:
- Connect R9 between J1:VBUS and IC3:IN for input supply. Already connected via Net
18d31f0397240630c649f04d09580c08. - Ensure R10 between BT1:(+) and IC3:OUT sets the charge current suitably. Already connected via
18d31f0397240630c649f04d09580c08. - Make sure R8 is properly setting the PRETERM charge termination condition via Net
48ebe8ea3929186fec02b93205705eff.
- Connect R9 between J1:VBUS and IC3:IN for input supply. Already connected via Net
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Integrating TPS61221DCKR Boost Converter:
- Input (VIN) Connection: Connect U2:VIN to BT1:(+), allowing the battery to directly supply the TPS61221. Since the VL-2330 is a lithium coin cell, ensuring its voltage matches the TPS61221's recommended operating range is essential.
- Output (VOUT) Connection: Connect U2:VOUT directly to the OLED1:(5V), providing it with the boosted voltage.
- Ground Connection: Ensure U2:GND is connected to the system ground, which looks to be managed via the various GND nets. Based on your schematic, ensuring a single connected ground network between BT1:(-), IC3:VSS_1, IC3:VSS_2, and U2:GND is necessary.
- Feedback and Enable Pins: The feedback (FB) pin of U2 naturally connects to an internal voltage divider. You don't need to connect it externally unless you're adjusting the output voltage away from the default. For simplicity, leaving FB as is should be fine. Connect U2:EN to a GPIO on IC1 if you want software control over the boost converter or tie it to VIN for always-on operation.
- Inductor and Capacitor: The TPS61221 requires an external inductor connected to U2:L and capacitors on both input and output for stable operation. Often, a value around 2.2µH for the inductor and 10µF for both input and output capacitors is a good start, adjusted based on your specific requirements and the TPS61221 datasheet recommendations.
- Connect U2:VIN to BT1:+.
- Connect U2:GND to BT1:-, IC3:VSS_1, and IC3:VSS_2.
- Connect U2:VOUT to OLED1:5V.
- Optional: Connect U2:EN to IC1 GPIO (for software control) or directly to BT1:+ for always-on.
Your charging circuit appears correctly configured for the BQ24095DGQR functionalities, with charging indication provided by D1 and proper feedback set by resistors. Integrating the TPS61221 requires direct connections to the battery for input and to the OLED for output, respecting ground coherence across the system. Ensure the TPS61221's peripheral components (inductors and capacitors) are chosen in line with Texas Instruments' datasheet to ensure stable operation.
2y
5
IC2
U3
U1
IC4
L1
Inductance
4.7 µH
C12
Capacitance
0.1µF
U2
C5
Capacitance
0.1µF
C3
Capacitance
10µF
C7
Capacitance
10µF
R6
Resistance
1kΩ
R2
Resistance
5kΩ
R5
Resistance
1kΩ
C4
Capacitance
10µF
C6
Capacitance
4.7µF
C13
Capacitance
0.1µF
R1
Resistance
5kΩ
C8
Capacitance
0.1µF
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