An apparatus and method for translating voltages between logic levels is provided having an input section (11), a level shifter section (89) and an output section (137). Input section (11) provides two control voltages to the level shifter section (89) in response to an input signal provided at input terminal (12). Level shifter section (89) comprises two inverters coupled to the control voltages. One inverter comprises p channel field-effect transistor (90) and n channel field-effect transistor (98). Another inverter comprises p channel field-effect transistor (106) and n channel field-effect transistor (114). For each inverter, the channel of the p channel field-effect transistor is over twice as wide as the channel of the n channel field-effect transistors. Each transistor (90, 98, 106 and 114) conducts current in response to a control voltage being anywhere within the voltage range, such that outputs of the inverters transition quickly in reponse to a transition of the control voltages. Output section (137) generates an output signal in response to the inverter outputs.

An open drain driver circuit includes first and second NMOS driver transistors, a delay circuit, an OR gate and an AND gate. Each NMOS driver transistor has a drain coupled to an output terminal, a source coupled to a supply terminal, and a gate. The delay circuit has an input coupled to the input terminal and has an output. The OR gate has a first input coupled to the input terminal, a second input coupled to the output of the delay circuit and an output coupled to the gate of the first NMOS transistor. The AND gate has a first input coupled to the input terminal, a second input coupled to the output of the delay circuit and an output coupled to the gate of the second NMOS transistor.

In a driving circuit supplied with an input signal having one of logic one and zero levels and producing an output signal through an output terminal to drive a load circuit connected to the output terminal, a first MOS transistor (26) is put into a first source-drain conductive state to produce a predetermined positive voltage (VDD) as the output signal when the input signal has the logic one level. The first MOS transistor has a first channel between its source and drain terminals. A second MOS transistor (27) is put into a second source-drain conductive state to produce a ground potential as the output signal when the input signal has the logic zero level. The second MOS transistor has a second channel between its source and drain terminals. Each of the first and the second channels has a restricted channel width to restrict source-drain currents flowing through the first and the second channels. A subsidiary drive circuit (30) drives the load circuit during transition time interval each time when the input signal changes from one of the logic one and zero levels to another of the logic one and zero levels.

A clock splitter device for forming a clock/inverted clock signal pair. The input clock signal is sent through an initial buffer stage and applied to two parts of a second stage. The second stage includes a single stage buffer and constricted inverter to provide two inverted outputs. The transistor arrangement of these two parts provides an equal delay to the two signal paths. The outputs of these two parts are sent to identical output buffers. Because the two paths have identical transistor delays, and since the metal paths on the board are arranged to have identical delays, the two paths can very low skew therebetween.

A noise limited, video, digital to analog converter having an output transition time control with multiple discrete transition times. This is accomplished by a DAC control circuit in which the slew rate of the current is controlled by providing set current levels in the inverters that drive the DAC output current switches thus limiting the current available for charging and discharging the capacitance on the nodes which control the output signal. Additional control is provided by voltage clamping of these nodes which reduces the input voltage to the analog output and results in a cleaner output waveform. By so regulating and controlling the charging and discharging of these nodes, the variations in operation of the circuit due to the process used to produce the circuit in integrated form as well as temperature and supply voltage are further substantially reduced.