The 12 Volt Combo chip is a combination spindle motor driver, voice coil driver and D/A converter. The part can be used in,application like HDD. The VCM amplifiers drive a low impedance coil and are set up to accept RC compensation, which allows a wide bandwidth with absolute minimum phase lag. The sense resistor/amplifier arrangement allows full current loop operation. The loop gain is changeable by attenuating the VCM DAC voltage amplitude in cascadable stages. The Spindle driver is a PWM only voltage loop with power supply feedforward, driving a 3 phase sensorless brushless DC motor. Since it uses PWM operation at full run speed, it has output slew rate control during start and run modes. There is an inductive clamp circuit to limit flyback voltage transients across the supply voltage during motor phase changes and during the braking sequence. Only the 2 phase or bipolar commutation pattern is produced by the internal commutation circuitry. A commutation register allows arbi-