SCEU012A April   2018  – July 2021 SN74AVC4T245 , SN74AVC4T245-Q1 , SN74AXC1T45 , SN74AXC8T245

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Features
    2. 1.2 Hardware Description
      1. 1.2.1 Headers
      2. 1.2.2 Bypass Capacitors
      3. 1.2.3 Pullup and Pulldown Resistors
      4. 1.2.4 SMB Connectors
  3. 2Board Layout
  4. 3Schematic and Bill of Materials
    1. 3.1 Schematic
    2. 3.2 Bill of Materials
  5. 4Revision History

1.1 Features

The AXC family of direction controlled translation devices are dual-supply with configurable voltage translation and an operating range from 0.65 V to 3.6 V. The A port is designed to track VCCA. VCCA accepts any supply voltage from 0.65 V to 3.6 V. The B port is designed to track VCCB. VCCB accepts any supply voltage from 0.65 V to 3.60 V. This device is fully specified for partial-power-down applications using IOFF. The IOFF circuitry disables the outputs, thus preventing damaging current backflow through the device when it is powered down. The VCC isolation feature ensures that if either VCC input is at ground, both A and B data I/O ports are in the high-impedance state.

The eight channel SN74AXC8T245 device has two direction control pins, each controlling 4 data I/Os enabling independent and simultaneous up and down translation. The DIR1 pin controls the direction of data I/O channels 1 through 4, and the DIR2 pin controls the direction of data I/O channels 5 through 8. The functional table of the SN74AXC8T245 is listed in Table 1-1 and the SN74AXC1T45 is listed in Table 1-3. Refer to SN74AXC8T245EVM for testing SN74AXC8T245PW package.

This EVM is designed to support SN74AXC1T45 in DEA and the DTQ packages. There is an option of populating the SN74AXC8T245 in the RJW package and SN74AVC4T245 or the SN74AXC4T245 in the RSV package. It is also designed to support the bus-hold and -Q1 devices for the respective channel counts.

Table 1-1 Function: SN74AXC8T245
OEDIR1DIR2Signal Direction
HXXHi-Z
LLLB data to A bus
LLHB{1:4} to A{1:4} and A{5:8} to B{5:8}
LHLA data to B bus
LHHA{1:4} to B{1:4} and B{5:8} to A{5:8}
Table 1-2 Function: SN74AXC4T245
OEDIR1DIR2Signal Direction
HXXHi-Z
LLLB data to A bus
LLHB{1:2} to A{1:2} and A{3:4} to B{3:4}
LHLA{1:2} to B{1:2} and B{3:4} to A{3:4}
LHHA data to B bus
Table 1-3 Function: SN74AXC1T45
DIRSignal Direction
LB data to A bus
HA data to B bus
GUID-6E13B127-BC1F-43C7-AA62-19B88C93E8B9-low.gifFigure 1-1 AXC-SMALLPKG1EVM: 8, 4, 2, 1 Channel versions

The supported packages are listed in Table 1-4.

Table 1-4 EVM Package Options
VersionPackageDevice Populated
One ChannelDEAYes
One ChannelDTQYes
Four ChannelRSVNo
Eight ChannelRJWNo