XR-2247

XR·2247/2247A Floppy Disk Write Amplifier GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM The XR-2247/2247A is a write amplifier designed to provide the complete interface between write data signals and tunnel-erase magnetic heads. Although primarily intended for floppy disk drive systems, the XR-22471 2247A can also be used in other magnetic media systems such as tape drives. To minimize external part count for dual head systems, complete head switching is does internally with emitter-coupled PNP transistors in the XR-2247 and diodes (which offer improved broadband noise characteristics) in the XR-2247A. Write and erase currents are each externally programmable with a single resistor. Also included is circuitry for inner track write current compensation. To prevent false write current outputs during power-on, an inhibit input has been provided. Erase turn-on and turn-off times are each externally programmable. The XR-2247/2247A, available in a 22-Pin DIP, operates from a single powe...