Low to high voltage conversion output driver

Abstract

A low to high voltage conversion output driver. The low to high voltage conversion output driver has an output coupled to a first fixed voltage via a load device and comprises a current source, a low voltage transistor, and a high voltage transistor. The current source has one end coupled to a second fixed voltage. The low voltage transistor has a first terminal coupled to the other end of the current source, a second terminal receiving a low voltage data signal, and a third terminal. The high voltage transistor has a first terminal coupled to the third terminal of the low voltage transistor, a second terminal coupled to a bias source, and a third terminal coupled to the output.

1 . A parallel to serial transmitter, comprising:
 a parallel to serial converter receiving a parallel data signal and generating a low voltage serial data signal; and   a low to high voltage conversion output driver receiving and converting the low voltage serial data signal to a high voltage serial data output signal.   
   
   
       2 . The parallel to serial transmitter as claimed in  claim 1 , further comprising a load device coupled to an output of the low to high voltage conversion output driver. 
   
   
       3 . The parallel to serial transmitter as claimed in  claim 2 , wherein the load device is a resistor. 
   
   
       4 . An output driver for driving a serial link, the output driver comprising:
 a first transistor; and   a second transistor coupled to the serial link;   wherein a threshold voltage of the first transistor is lower than a threshold voltage of the second transistor, and the first and second transistors are cascaded-connected.   
   
   
       5 . The output driver as claimed in  claim 4 , wherein the serial link is a USB, PCI Express, SATA, or HDMI interface. 
   
   
       6 . An output driver for driving a serial link, the output driver comprising:
 a first transistor; and   a second transistor coupled to the serial link;   wherein the first transistor is a core device and the second transistor is not a core device, and the first and second transistors are cascaded-connected.   
   
   
       7 . The output driver as claimed in  claim 6 , wherein the serial link is a USB, PCI Express, SATA, or HDMI interface. 
   
   
       8 . An output driver for driving a serial link, the output driver comprising:
 a first transistor; and   a second transistor coupled to the serial link, a control terminal of the second transistor being coupled to a fixed voltage;   wherein the first and second transistors are cascaded-connected.   
   
   
       9 . The output driver as claimed in  claim 8 , wherein the serial link is a USB, PCI Express, SATA, or HDMI interface.