Patent ID: 7701654
Filing Date: 2010-04-20
Classification: G11B,H03F

Abstract:
1. An apparatus for supplying write current to a write head of a data storage device to write data bits to the data storage device, the apparatus comprising: a first and a second control element; a first and a second current source module for producing a respective first and second controllable current; a first and a second biasing module for applying a first and a second controllable bias to the respective first and second control elements; and a controller for controlling the first and the second current source modules to control the respective first and second currents and for controlling the first and the second biasing modules to control the bias, wherein: the first and the second current source modules each comprises a plurality of independently controllable parallel current source branches each supplying a branch current and each independently controlled by the controller, and wherein a sum of the branch currents of the first current source module comprises the first current and a sum of the branch currents of the second current source module comprises the second current.