SN74LVCH8T245_16 Datasheet, PDF (1/33 Pages) Texas Instruments – 8-BIT Dual-Supply Bus Transceiver

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SN74LVCH8T245
SCES637B – AUGUST 2005 – REVISED FEBRUARY 2016
SN74LVCH8T245 8-BIT Dual-Supply Bus Transceiver
With Configurable Level-Shifting, Voltage Translation, and 3-State Outputs
1 Features
•1 Control Inputs (DIR and OE) V_IH and V_IL Levels
are Referenced to V_CCA
• Bus Hold on Data Inputs Eliminates the Need for
External Pullup and Pulldown Resistors
• V_CC Isolation
• Fully Configurable Dual-Rail Design
• I_off Supports Partial-Power-Down Mode Operation
• Latch-Up Performance Exceeds 100 mA Per
JESD 78, Class II
• ESD Protection Exceeds JESD 22
2 Applications
• Personal Electronics
• Industrial
• Enterprise
• Telecommunications
3 Description
The SN74LVCH8T245 is an 8-bit noninverting bus
transceiver that uses two separate configurable
power-supply rails. The A port is designed to track
V_CCA, which accepts any supply voltage from 1.65 V
to 5.5 V. The B port is designed to track V_CCB, which
also accepts any supply voltage from 1.65 V to 5.5 V.
This allows for universal low-voltage bidirectional
translation between any of the 1.8-V, 2.5-V, 3.3-V,
and 5.5-V voltage nodes.
The SN74LVCH8T245 is designed for asynchronous
communication between two data buses. The logic
levels of the direction-control (DIR) input and the
output-enable (OE) input activate either the B-port
outputs, the A-port outputs, or place both output ports
into a high-impedance state. The device transmits
data from the A bus to the B bus when the B-port
outputs are activated, and from the B bus to the A
bus when the A-port outputs are activated. The input
circuitry on both A and B ports are always active.
The SN74LVCH8T245 is designed so that the control
pins (DIR and OE) are referenced to V_CCA.
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.
This device is fully specified for partial-power-down
applications using I_off. The I_off circuitry disables the
outputs, preventing damaging current backflow
through the device.
The V_CC isolation feature ensures that if either V_CCA
or V_CCB is at GND, then the outputs are in the high-
impedance state.
To ensure the high-impedance state during power up
or power down, OE should be tied to V_CCA through a
pullup resistor; the minimum value of the resistor is
determined by the current-sinking capability of the
driver.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
SSOP (24)
8.65 mm × 3.90 mm
SN74LVCH8T245
TVSOP (24)
TSSOP (24)
5.00 mm × 4.40 mm
7.80 mm × 4.40 mm
VQFN (24)
5.50 mm × 3.50 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Logic Diagram (Positive Logic)
2
DIR
3
A1
22
OE
21
B1
To Seven Other Channels
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.