• Resolved

[FAQ] Schematic Checklist for Wireless Power RX

Intellectual 1800 points

Replies: 1

Views: 22

This FAQ is applicable for wireless power RX like bq51013Bbq51050Bbq51003, and similar.

Nick Brylski

Applications Engineer

Battery Chargers | Texas Instruments

  •  

    1. AC1 and AC2
      1. See post here on C1/C2 calculation: https://e2e.ti.com/support/power-management/f/196/t/905132
      2. C1 - Series capacitance between coil and AC1. The ESR is reduced when three capacitors are used in parallel, higher efficiency / lower heating. Rated 25V.
      3. C2 - Capacitance between AC1/AC2, C2 low impact to performance. Rated 25V.
    2. COMM1 and COMM2
      1. Connect capacitors from COMM1 to either AC1 or AC2 and from COMM2 to the alternate AC1 or AC2 pin. Minimum 25V rating. The COMM caps should be about 15% of C1 capacitor value.
    3. BOOT1 and BOOT2
      1. Connect 10 nF capacitors from BOOT1 to AC1 and from BOOT2 to AC2. Minimum 25V rating.
    4. CLAMP1 and CLAMP2
      1. Connect 0.47 µF capacitors from CLAMP1 to AC1 and from CLAMP2 and AC2. Minimum 25V rating.
    5. /AD-EN and AD
      1. /AD-EN tied to gate of blocking FETS (see EVM as guide). Connect AD pin to the wired adapter input with 1 uF capacitor to ground.
      2. If wired adapter input is unused, capacitor is not required and AD should be grounded directly. Leave \AD-EN floating.
    6. OUT
      1. Add capacitance - min effective is 1uF but more is better, use 10uF if possible.
    7. TS/CTRL
      1. Connect TS-CTRL to ground through 10k NTC. If temperature function not used, use 10k resistor. TS calculator tool available here: www.ti.com/.../sluc629
      2. Connect with 3-state driver for CTRL function, refer to d/s “ 3-state driver for TS-CTRL”
    8. RECT
      1. Connect a 4.7 – 22 uF ceramic capacitor from RECT to PGND. Increasing bulk capacitance at RECT pin is effective to support load steps or noisy loads.
      2. Connect 20kΩ resistor (Ros) from RECT to FOD. 20kΩ is the default value, the final value need to be determined based on the FOD calibration, calibration tool available here: www.ti.com/.../sluc577
    9. FOD
      1. Connect 196Ω resistor (RFOD) from FOD to ground. 196Ω is the default value, the final value need to be determined based on the FOD calibration, calibration tool available here: www.ti.com/.../sluc577
      2. Good practice is to set the layout with 2 resistors for Ros and 2 for RFOD to allow for precise values once the calibration is complete.

    10. ILIM
      1. Connect ILIM to FOD through resistor, R1. With default value (196Ω) for RFOD, R1 = 328Ω sets current limit to 600mA (BQ51003). R1 = 66Ω sets current limit to 1.2A (BQ51013b)
      2. R1 must be adjusted after the FOD calibration (if RFOD value changes), refer to “RILIM Calculations” section of datasheet.
    11. /CHG
      1. Connected to MCU input or left floating.
    12. EN1 and EN2
      1. Connected to MCU output or left floating.

    Nick Brylski

    Applications Engineer

    Battery Chargers | Texas Instruments