Dallas -- Texas Instruments announced Tuesday (September 16) a 32-bit wide level translator, the AVCB324245. This device allows bi-directional level translation between 1.5V, 1.8V, 2.5V, and 3.3V logic levels. It useful in space-constrained consumer, networking, datacom, and computing applications, where one device (in one package) can adjust the logic levels on 32 separate lines, TI says. (A single SN74AVCB324245GKE - the AVCB324245 in a 96-ball LFBGA package, for example - occupies 50 percent of the space as two 16-bit devices, like TI's SN74AVCB164245DGG.)
The AVCB324245 implements an interface between two systems that have dissimilar trigger and out voltages, while maintaining signal integrity and speed. (The propagation delay is 3.7ns max, tested at 3.3V).
Mismatched I/O voltages between the microprocessors/microcontrollers and peripheral devices will continue to occur as core operating voltages migrate to lower nodes. For example, a logic "1" (or "high") for a 5V logic device (like TTL) is the same a 3.3V device (like CMOS logic). Any voltage higher than 2.4V can be interpreted as logic "1," but this voltage level can be dangerously close to a "false trigger region" that can prevail where differing logic families interface each other. Similarly, there are bus driver logic families whose maximum output voltage (2.1V) will hardly reach the turn-on threshold (2.4V) for another family. This makes it extremely difficult for devices to interface and maintain acceptable noise margins, TI says.
The AVCB324245 level-shifting logic transceiver is capable of providing a low-noise buffered interface with the low-voltage (1.5 and 1.8V) processor cores, and higher-voltage (3.3V) peripheral devices. In GSM cell phone displays, for example, LCD data (16-bits) and control signals (10 to 16-bits) are level-shifted from the lower-voltage baseband controller (operating at 1.95 to 2.7V) to the logic levels appropriate for the LCD module (2.7 to 3.6V).
The SN74AVCB324245KR (96-ball LFBGA, GKE) is currently available to sample. Budgetary pricing for the device is set at $5.28 in quantities of 1,000. Contact www.ti.com.