Registered Bus Exchanger 1-Element 56-Pin SSOP Tube

This 12-bit to 24-bit registered bus exchanger is designed for 1.65-V to 3.6-V VCC operation. The SN74ALVCH162268 is used for applications in which data must be transferred from a narrow high-speed bus to a wide, lower-frequency bus. The device provides synchronous data exchange between the two ports. Data is stored in the internal registers on the low-to-high transition of the clock (CLK) input when the appropriate clock-enable (CLKEN)\ inputs are low. The select (SEL)\ line is synchronous with CLK and selects 1B or 2B input data for the A outputs. For data transfer in the A-to-B direction, a two-stage pipeline is provided in the A-to-1B path, with a single storage register in the A-to-2B path. Proper control of these inputs allows two sequential 12-bit words to be presented synchronously as a 24-bit word on the B port. Data flow is controlled by the active-low output enables (OEA\, OEB\). These control terminals are registered, so bus direction changes are synchronous with CLK. The B outputs, which are designed to sink up to 12 mA, include equivalent 26-O resistors to reduce overshoot and undershoot. To ensure the high-impedance state during power up or power down, a clock pulse should be applied as soon as possible and OE should be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. Due to OE being routed through a register, the active state of the outputs cannot be determined prior to the arrival of the first clock pulse. Active bus-hold circuitry holds unused or undriven inputs at a valid logic state. Use of pullup or pulldown resistors with the bus-hold circuitry is not recommended.

Member of the Texas Instruments Widebus™ Family

Operates From 1.65 V to 3.6 V V_CC

Max t_pd of 4.8 ns at 3.3 V V_CC

±24 mA Output Drive at 3.3 V V_CC

B-Port Outputs Have Equivalent 26-O Series Resistors, So No External Resistors Are Required

Bus Hold on Data Inputs Eliminates the Need for External Pullup/Pulldown Resistors

Latch-Up Performance Exceeds 250 mA Per JESD 17

ESD Protection Exceeds JESD 22

• 2000-V Human-Body Model (A114-A)
• 200-V Machine Model (A115-A)