ANB4100

The ANB4100 operates from 2.5V to 5.5V, making it suitable for single-cell Li-ion (3.0V-4.2V), 3xAA alkaline (4.5V), or USB-powered (5V) applications. At 2.5V minimum, it can operate from a nearly depleted single-cell Li-ion battery, extending usable battery life. The UVLO threshold is typically 2.3V with 200mV hysteresis to prevent oscillation. For reliable operation, ensure your power supply can deliver the required motor current at minimum voltage - a battery at 2.5V may have high internal resistance limiting current delivery.

Use for single-cell Li-ion, 3xAA, or USB-powered applications. Verify battery can deliver required current at low voltage.

Motor speed control uses PWM (Pulse Width Modulation) applied to the IN1 or IN2 input while holding the other input low. PWM frequency can range from 100Hz to 100kHz, though 10-20kHz is typical to avoid audible noise. Duty cycle determines speed: 0% = stop, 50% = half speed, 100% = full speed. For direction control, apply PWM to IN1 for forward, IN2 for reverse. The device includes internal current regulation that limits peak current during PWM switching, protecting the motor and driver. For smooth speed control, use PWM frequencies above 15kHz to avoid audible motor winding noise.

Use 10-20kHz PWM frequency for speed control. Apply PWM to IN1 or IN2 for forward/reverse control.

The ANB4100 features an ultra-low-power sleep mode with typical current consumption of <1μA (maximum 5μA). To enter sleep mode, set both IN1 and IN2 low for more than 1ms. The device automatically enters sleep mode, disabling all internal circuits except the wakeup logic. To exit sleep mode, set either IN1 or IN2 high. Wakeup time is typically 50μs. This feature is essential for battery-powered applications where the motor runs infrequently. For example, in a smart lock that operates 10 times per day, the sleep mode current dominates battery life. With 1μA sleep current and 100mA motor current for 3 seconds per operation, average current is approximately 4μA, providing years of battery life from AA cells.

Set IN1=IN2=LOW for >1ms to enter sleep mode. Set either input HIGH to wake up. Use for maximum battery life.

The ANB4100 includes integrated current regulation with a fixed threshold of 1.5A (typical). When motor current exceeds this threshold, the driver automatically limits current using PWM chopping at approximately 50kHz. This protects the driver and motor from stall conditions without requiring external current sense resistors. For lower current limits, you can implement external current sensing with a small resistor (0.1-0.5Ω) and comparator to disable the driver when current exceeds your threshold. The internal current regulation is sufficient for most applications, providing protection against stall and overload conditions. Note that during current limiting, the motor may vibrate or buzz due to the chopping frequency.

Internal 1.5A current limit is automatic. Use external sensing for custom current limits. Expect audible noise during current limiting.

PCB layout guidelines for ANB4100: 1) Place bulk capacitor (10-100μF) close to VM pin for motor supply decoupling. 2) Add ceramic capacitor (0.1μF) very close to VM pin for high-frequency decoupling. 3) Use wide traces for motor output pins (OUT1, OUT2) to handle 1.2A current. 4) Connect GND pin to solid ground plane with multiple vias. 5) Keep logic input traces (IN1, IN2) away from motor output traces to prevent noise coupling. 6) Use thermal vias under the SOT23-6 package if operating near 1A continuous. 7) Place flyback diodes close to motor terminals if using external diodes (not needed for most applications as driver has internal diodes). The compact SOT23-6 package allows placement close to the motor connector for minimal trace length.

Place capacitors close to VM pin. Use wide traces for motor outputs. Keep logic traces away from motor traces.