SN74AXCH4T245 Texas instruments

The SN74AXCH4T245 is a four-bit noninverting bus transceiver that uses two individually configurable power-supply rails. The device is operational with both VCCA and VCCB supplies as low as 0.65 V. The A port is designed to track VCCA, which accepts any supply voltage from 0.65 V to 3.6 V. The B port is designed to track VCCB, which accepts any supply voltage from 0.65 V to 3.6 V. The SN74AXCH4T245 device is compatible with a single-supply system.The SN74AXCH4T245 device is designed for asynchronous communication between data buses and transmits data from the A bus to the B bus or from the B bus to the A bus, depending on the logic level of the direction-control inputs (1DIR and 2DIR). The output-enable inputs (1OE and 2OE) are used to disable the outputs so the buses are effectively isolated. All control pins (xDIR and xOE) are referenced to VCCA.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. If a supply is present for VCCA or VCCB, the bus-hold circuitry always remains active on the A or B inputs respectively, independent of the state of the direction control or output enable pins.To ensure the high-impedance state of the level shifter I/Os during power up or power down, the xOE pins should be tied to VCCA through a pullup resistor.This device is fully specified for partial-power-down applications using the Ioff current. The Ioff protection circuitry ensures that no excessive current is drawn from or sourced into an input, output, or combined I/O that is biased to a specific voltage while the device is powered down.The VCC isolation feature ensures that if either VCCA or VCCB is less than 100 mV, all I/O ports enter a high-impedance state by disabling the outputs.Glitch-free power supply sequencing allows either supply rail to be powered on or off in any order while providing robust power sequencing performance.

Technology family	AXC
Applications	JTAG, SPI, UART
Bits (#)	4
High input voltage (min) (V)	0.455
High input voltage (max) (V)	3.6
Vout (min) (V)	0.65
Vout (max) (V)	3.6
Data rate (max) (MBits)	380
IOH (max) (mA)	-12
IOL (max) (mA)	12
Supply current (max) (µA)	20
Features	Bus-hold, Output enable, Overvoltage tolerant inputs, Partial power down (Ioff), Vcc isolation
Input type	Standard CMOS
Output type	3-State, Balanced CMOS, Push-Pull
Rating	Catalog
Operating temperature range (°C)	-40 to 125