Abstract: A voltage translator uses an n-channel translator transistor to translate an input voltage at its drain to an output voltage at its source. The gate and substrate of the translator transistor are each biased by charge pumps. A reference transistor is also biased by the charge pumps. A reference input voltage is translated to a reference output voltage by the reference transistor. The reference output voltage is compared to a target output voltage by comparators. When the reference output voltage is below the target, the gate charge pump is turned on, raising the gate voltage to both the reference and translator transistors. The higher gate voltage VGATE raises the output voltage VOUT since VOUT=VGATE-VT for a transistor in saturation. When the reference output voltage is above the target, the substrate charge pump is turned on, pulling the substrate bias voltage below ground. The body effect causes the transistor threshold VT to increase as the substrate is pumped.

Abstract: A micro-relay replaces electromechanical and solid-state opto-isolated relays in a computer network. The micro relay is an integrated circuit containing several bus switches in parallel. Each bus switch can make or break a connection. The bus switch is an n-channel MOS transistor with the source and drain connected to different network busses. A bus enable input causes the connection to be made or broken. The bus enable input is separately buffered for each gate of each MOS transistor to prevent crosstalk between bus switches. Since the MOS transistor stops conducting when the source is at a voltage level of the power-supply voltage minus the threshold voltage, a boosted voltage is applied to the gate of the MOS transistor to allow conduction even when the source is at the power-supply voltage level. The boosted voltage is generated by a charge pump. A substrate bias is applied to the transistors to prevent crosstalk from undershoots.

Abstract: A network switch uses a simple switch core of analog MOS transistor switches. The switch core is surrounded by many media-access controllers (MAC's) which buffer the data through the switch core. Multiple connections through the switch core may be made between different pairs of MAC's. Just one signal path through the switch core is needed per connection as a second path through the switch core for the clock is not needed. The clock is not encoded with the data, so PLL's are not needed for clock recovery. Data skew is instead measured for each packet transmitted through the switch core. A start flag is added to the packet by a source MAC as a packet header before being transmitted through the switch core. The start flag is a unique sequence which is detected by the destination MAC and triggers measurement of the data skew of the received start flag to the local clock. The measured data skew is then used to compensate for the rest of the packet.