Bidirectional Voltage Translator
Created: Feb 18, 2014
No description available.
The NVT2001/02 are bidirectional voltage level translators operational from 1.0V to 3.6V Vref (A) and 1.8V to 5.5V Vref (B), which allow bidirectional voltage translations between 1.0V and 5.0V without the need for a direction pin in open-drain or push-pull applications. Bit widths ranging from 1-bit or 2-bits are offered for level translation application with transmission speeds lesser than 33 MHz for an open-drain system with a 50-pF capacitance and a pull-up of 197Ω.
When the A(n) or B(n) port is LOW, the clamp is in the ON-state and a low resistance connection exists between the A(n) and B(n) ports. The low ON-state resistance of the switch allows connections to be made with minimal propagation delay. Assuming the higher voltage is on the B(n) port when the B(n) port is HIGH, the voltage on the A(n) port is limited to the voltage set by Vref (A). When the A(n) port is HIGH, the B(n) port is pulled to the drain pull-up supply voltage by the pull-up resistors. This functionality allows a seamless translation between higher and lower voltages selected by the user without the need for directional control. When EN is HIGH, the translator switch is ON, and the A(n) I/O is connected to the B(n) I/O, respectively, allowing bidirectional data flow between ports. When EN is LOW, the translator switch is OFF, and a high-impedance state exists between ports. The EN input circuit is to be supplied by Vref (B). To ensure the high-impedance state during power-up or power-down, EN must be LOW.
All channels have the same electrical characteristics and there is minimal deviation from one output to another in voltage or propagation delay. This is a benefit over discrete transistor voltage translation solutions, since the fabrication of the switch is symmetrical. The translator provides excellent ESD protection to lower voltage devices, and at the same time protects less ESD-resistant devices.