An apparatus and system for a clock buffer. The clock buffer comprises a source follower, and the source follower comprises a voltage source and a resistor.

Apparatus and methods for radio frequency (RF) switch control are provided. In certain embodiments, a level shifter for an RF switch includes a first level-shifting n-type transistor, a first cascode n-type transistor in series with the first level-shifting n-type transistor between a negative charge pump voltage and a first output that provides a first switch control signal, a first level-shifting p-type transistor, a first cascode p-type transistor in series with the first level-shifting p-type transistor between a positive charge pump voltage and the first output, and a second cascode p-type transistor between a regulated voltage and a gate of the first level-shifting n-type transistor and controlled by a first switch enable signal.

A clock signal delay path unit includes a first delay cell including a first root signal line for delaying and transmitting a clock signal, a first repeater to transmit the clock signal transmitted through the first root signal line without signal attenuation, and a second root signal line for delaying and transmitting the clock signal output from the first repeater, a second delay cell including a first inverting circuit configured to invert the clock signal provided from the first delay cell to generate an inverted clock signal, and a third delay cell including a first branch signal line for delaying and transmitting the inverted clock signal provided from the second delay cell, a second repeater to transmit the inverted clock signal transmitted through the first branch signal line, and a second branch signal line for delaying and transmitting the inverted clock signal output from the second repeater.

Systems and methods associated with reducing clock skew are disclosed. In some exemplary embodiments, there is provided circuitry associated with lock loop circuits such as a phase lock loop (PLL). Such circuitry may comprise output clock tree circuitry and phase averaging circuitry. In other exemplary embodiments, there is provided circuitry associated with delay lock loop (DLL) circuits. Such circuitry may comprise output clock tree circuitry and/or phase averaging circuitry.

In certain aspects, an apparatus includes a gating circuit having an enable input, a signal input, and an output, wherein the enable input is configured to receive an enable signal. The apparatus also includes a toggle circuit having an output, wherein the toggle circuit is configured to toggle a logic state at the output of the toggle circuit based on the enable signal. The apparatus further includes a multiplexer having a first input, a second input, and an output, wherein the first input of the multiplexer is coupled to the output of the gating circuit, the second input of the multiplexer is coupled to the output of the toggle circuit. The multiplexer is configured to select one of the first input and the second input based on the enable signal, and couple the selected one of the first input and the second input to the output of the multiplexer.

A clock generation circuit may include a first clock generator, a second clock generator, and a common mode generator. The first clock generator may generate a multi-phase clock signal from a first clock signal. The second clock generator may generate a multi-phase clock signal from a second clock signal. The common mode generator may generate a reference voltage based on the first and second clock signals.

A filter circuit includes a polyphase filter used to generate a plurality of output signals with different phases according to a plurality of input signals. The polyphase filter includes a switch circuit and a feed-forward capacitor. The switch circuit has a control terminal used to receive a control voltage, a first connection terminal used to output one of the output signals, and a second connection terminal used to receive one of the input signals. The feed-forward capacitor has a first plate coupled to the second connection terminal of the switch circuit and a second plate coupled to the control terminal of the switch circuit.

A signal generation apparatus for use with a ToF camera system includes a first pulse generator configured to generate a pulse to be supplied to a light source that irradiates light to a distance measurement target, a second pulse generator configured to generate a pulse to be supplied to pixels that receive light reflected by the distance measurement target, and a switching section configured to switch a setting of a modulation frequency of the first pulse generator and the second pulse generator within a predetermined period.

A clock signal delay path unit includes a first delay cell including a first root signal line for delaying and transmitting a clock signal, a first repeater to transmit the clock signal transmitted through the first root signal line without signal attenuation, and a second root signal line for delaying and transmitting the clock signal output from the first repeater, a second delay cell including a first inverting circuit configured to invert the clock signal provided from the first delay cell to generate an inverted clock signal, and a third delay cell including a first branch signal line for delaying and transmitting the inverted clock signal provided from the second delay cell, a second repeater to transmit the inverted clock signal transmitted through the first branch signal line, and a second branch signal line for delaying and transmitting the inverted clock signal output from the second repeater.

A clock signal delay path unit includes a first delay cell including a first root signal line for delaying and transmitting a clock signal, a first repeater to transmit the clock signal transmitted through the first root signal line without signal attenuation, and a second root signal line for delaying and transmitting the clock signal output from the first repeater, a second delay cell including a first inverting circuit configured to invert the clock signal provided from the first delay cell to generate an inverted clock signal, and a third delay cell including a first branch signal line for delaying and transmitting the inverted clock signal provided from the second delay cell, a second repeater to transmit the inverted clock signal transmitted through the first branch signal line, and a second branch signal line for delaying and transmitting the inverted clock signal output from the second repeater.