Off-Chip Driver Circuit
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
A tristate off chip driver (OCD) circuit disclosed herein pulls its output voltage to ground potential prior to switching from an active state to a high impedance state. The figure shows a logic implementation of an OCD 10 and a pulse generator 12. A pulse having a short duration is generated when an enable/disable input is switched from a high voltage level to a low voltage level. The width of the generated pulse is determined by the number of inverters 14 which are included in a delay chain 16. The generated pulse, which is applied to node 2 of the OCD 10, is inverted by a NAND gate 18. A positive voltage transition appearing on the output of the NAND gate 18 turns on transistor T1 thereby placing ground potential on an output node 20.