Write driver circuit

Abstract

A write driver for writing write data to a magnetic disk. The write driver is provided with first and second pnp type input transistors whose bases are each supplied with a pair of complementary input signals, and first and second npn type output transistor in the form of an inverted Darlington arrangement. A first resistor element is provided between the emitter of a corresponding pnp type input transistor and the collector of a npn type output transistor, whereas a second resistor element is provided between the common collector of the first and second npn type output transistors and supply voltage. The collectors of the first and second pnp type transistor are supplied with clamp voltage. Third and fourth npn type output transistors each connected to the first and second npn type output transistors in series and subjected to complementary switching control are provided to form a bridge circuit and to drive an inductive head.