Motor Drivers

The L298N is a bipolar-junction H-bridge: it can handle up to 46 V and 2 A per channel but drops 1.4-2.5 V across its Darlington outputs, wasting power as heat and starving low-voltage motors. The TB6612FNG and DRV8833 use MOSFET bridges with a fraction of the voltage drop, run far cooler and include built-in flyback diodes, but are limited to about 15 V and 1.2-1.5 A. Use L298N only for higher-voltage, moderate-current loads or legacy compatibility; choose TB6612FNG or DRV8833 for battery-powered robots and anything efficiency-sensitive.

They are pin-compatible on the common Pololu-style breakout footprint and both drive bipolar steppers up to about 2 A, but they differ in three important ways. Microstepping: the DRV8825 goes to 1/32 while the A4988 tops out at 1/16. Current setting: the VREF-to-current formula is different (A4988 uses VREF/(8×RSENSE), DRV8825 uses VREF/(5×RSENSE)), so you must re-tune when swapping. And the microstep mode-select truth table above 1/8 does not match, so firmware pin mapping may need changing. DRV8825 is generally the quieter, smoother upgrade.

It depends on the part. The TB6612FNG, DRV8833, A4988 and DRV8825 all integrate clamp/regeneration diodes, so no external flyback diodes are needed for normal inductive motor loads. The L298N does NOT include them — you must add external fast diodes (for example 1N5819 or FR107) across each motor terminal to ground and supply, or the output stage will be destroyed by back-EMF when the coil current is interrupted.

A gate driver is not a motor driver by itself — it is a high-current buffer that switches the gate of one or more external power MOSFETs quickly and cleanly. Use the TC4420 (low-side, 6 A) to drive a single MOSFET hard for PWM speed control of a large motor, and the IR2110 (high-side + low-side, with bootstrap) to build a half-bridge or full-bridge from discrete MOSFETs when you need more current or voltage than an integrated driver can supply. They are essential in high-power BLDC, solenoid and H-bridge designs built from IRF3205-class MOSFETs.