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3.7 KiB

H-Bridge breakout PCB for CP2119L or TMI8260SP

  • For driving DC motors, coils and other inductive loads
  • Bi-directional output
  • Up to 18V, 5A
  • Works with 1.8 - 5.0V logic
  • Overcurrent protection
  • Short circuit protection
  • Overheat protection
  • Integrated flyback diodes
  • Pretty idiot-proof

Basic operation

  • Logic HIGH on the FORWARD pin makes the motor spin FORWARD (M+ becomes VIN, M- becomes GND)
  • Logic HIGH on the REVERSE pin makes the motor spin REVERSE (M+ becomes GND, M- becomes VIN)
  • Logic HIGH on BOTH pins makes the motor ACTIVELY BREAK (M+ becomes GND, M- becomes GND)
  • Logic LOW on BOTH pins makes the motor FREESPIN (M+ floats, M- floats)

"Analog" control

  • The power of the motor can be precisely adjusted (0-100%) by applying a PWM SQUARE WAVE to the FORWARD/REVERSE pins
  • Recommended PWM frequency: 100Hz - 5KHz
  • "analogWrite()" on Arduino produces a suitable 490Hz square wave with 255 levels of control

PCB assembly / component configurations

For Voltage 3-18V and Current 0-5A (basic configuration)

  • Populate the TMI8260 (duh!). Note where pin 1 (marked) goes!
  • Populate '2x10uF' with included ceramic capacitors
  • Populate '220uF' with included polymer aluminium capacitor. Note where the negative goes!
  • Skip the additional flyback diodes
  • This works with PWM frequencies up to 5KHz

For PWM frequency > 5KHz

  • If the expected current is low (<3A), you can probably just use the basic configuration
  • Otherwise, add 4x flyback diodes on the PCB
  • SS54 or SS34 diodes, in SOD-123L package
  • They are difficult to solder, sorry!

For Voltage<10V AND Current<2A:

If you don't need the high power of this chip, consider using the DRV8835 module instead. It is cheaper and comes pre-assembled.

For ONE directional control:

If you don't need bi-directional control, consider just using a N-MOSFET and flyback diode instead. Cheaper, simpler.

Built in protections

The TMI8260/CP2119 has protection features that allow it to protect ITSELF

  • It cannot protect the connected motor/coil - make sure VIN is a voltage that the motor can handle!
  • It cannot fully protect the power source - make sure it can handle the current the motor will take!

Overcurrent / short-circuit protection

  • If the connected motor / coil attempts to take more than > 9A, overcurrent protection kicks in
  • The device will stop supplying power for approx 50 microseconds, and let the current drop
  • After that, the device will automatically retry applying current
  • This is very helpful when starting large motors from a standstill - the surge current will be effectively limited, and the motor will slowly spin up instead of taking infinity amperes.
  • This does protect the power source by limiting the consumed current to approx 9A
  • This feature relies on the inductance of the connected motor/coil. If the inductance is too low, the safety feature will not have time to react before the current becomes too high.

Overtemperature protection

  • If the TMI8260 gets too hot (>150C) during continuous operation, it will temporarily stop providing power to the load
  • After cooling down, it will automatically return to normal operation

Integrated flyback diodes

  • Inductive loads tend to induct reverse voltages that may damage drive circuitry
  • The TMI8260 has integrated flyback diodes (inside the chip) that can handle most use cases
  • The PCB has space for additional external flyback diodes, for more extreme cases (see "Use cases")

Parts included in the kit:

  • Breakout PCB
  • TMI8260SP-MS chip (datasheet in Chinese)
  • Polymer aluminium capacitor (SHENGYANG SM227M025E0600 220uF 25V)
  • 3x Ceramic capacitors (10uF 25V 0603)