Patent ID: 7187197
Filing Date: 2007-03-06
Classification: G06F,H03K

Abstract:
1. A transmission line driver with slew rate control, comprising: a high side ramp generator that receives a speed signal and a data signal and generates a charge ramp signal; a low side ramp generator that receives the speed signal and the data signal and generates a discharge ramp signal; a first comparator having a first input that receives the charge ramp signal, a second input that receives a first reference voltage signal, and a first comparator output signal; a second comparator having a first input that receives the discharge ramp signal, a second input that receives a second reference voltage signal, and a second comparator output signal; an NMOS source follower transistor having a gate connected to the high side ramp generator and receiving the charge ramp signal, and a drain connected to a first voltage level; a PMOS source follower transistor having a gate connected to the low side ramp generator and receiving the discharge ramp signal, a drain connected to a ground, and a source connected to a source of the NMOS source follower transistor, wherein a node between the sources of the NMOS and PMOS source follower transistors is an output node; a pair of additional drivers including a PMOS transistor having a gate connected to the first comparator and receiving the first comparator output signal, and a source connected to the first voltage level, and a NMOS transistor having a gate connected to the second comparator and receiving the second comparator output signal, a source connected to the ground, and a drain connected to a drain of the PMOS additional transistor and the output node; and a pair of staggered drivers including a PMOS transistor having a gate connected to the first comparator and receiving the first comparator output signal, a source connected to the first voltage level, and a drain connected to the output node, and a NMOS transistor having a gate connected to the second comparator and receiving the second comparator output signal, a source connected to the ground, and a drain connected to the output node.