H‑Bridge motor driver module (2×) using NXP/Freescale MPC17511A.

• Two independent full H‑bridges (U1, U2) for driving two DC motors
• Separate supplies for logic (VDD) and motor power (VM)
• Designed for battery‑powered robots and small mechatronics
• Supports PWM up to 200 kHz (modulation on INx or ENx)

Each bridge (A/B) exposes the following signals.

• VM — Motor supply input (2.0–6.8 V)
• VDD — Logic supply input (2.7–5.7 V)
• PGND, LGND — Power/logic grounds (tie at the module)
• OUT1x, OUT2x — Motor outputs (channel x = A/B)
• IN1x, IN2x — Direction inputs
• ENx — Enable input (can be PWM’d)
• GIN#, GOUT — Gate‑drive I/O for an optional external high‑side N‑FET (not populated on the module)

Note: The IC separates VM and VDD, allowing direct battery drive for the motor while powering the controller from a regulated VDD.

• ENx = H, IN1x = H, IN2x = L → Forward (OUT1x = H, OUT2x = L)
• ENx = H, IN1x = L, IN2x = H → Reverse (OUT1x = L, OUT2x = H)
• ENx = H, IN1x = H, IN2x = H → Brake (low‑side conduction)
• ENx = H, IN1x = L, IN2x = L → Coast (outputs off/high‑Z)
• ENx = L → Bridge disabled / low‑power

Refer to the MPC17511A datasheet for the complete truth table and timing.

• Motor EMI suppression: Place a 4.7 nF ceramic directly across the motor terminals. If needed, add small series chokes in both motor leads.
• Power domain isolation: Keep motor current loops short. Feed the controller from VDD via an RC/LC filter and regulator. Star‑connect grounds; join the controller ground to module ground, not directly at the battery.
• Reverse‑polarity & back‑EMF: Input diodes protect against reversed supply. A Zener clamp on VM limits voltage if the motor back‑drives the bridge (e.g., someone spins the motor by hand). Keep VM < 8 V at all times.
• Defined input state: The IC does not include internal pull‑downs on IN1x/IN2x. To prevent a floating state at power‑up, populate 100 kΩ pull‑downs from each IN1x and IN2x to GND (four resistors total across both bridges).

• SMD components are on the bottom; pin headers and mechanical hardware are on the top.
• Solder fine‑pitch ICs first; use minimal solder and appropriate SMD flux. Diode cathodes and capacitor positive pads are rounded in the silkscreen for orientation.

1. Power VDD and VM with current‑limited supplies; slowly raise VM to ~5 V during bring‑up.
2. Drive IN1x/IN2x/ENx per the functional summary and verify motor direction and braking.
3. Apply PWM (0–200 kHz) on INx or EN as required by your control strategy.