The part number " SN74LVC4245APW R" is a product manufactured by Texas Instruments (TI). It is a dual-direction 8-bit bus transceiver that is part of the SN74LVC series, which is known for low-voltage CMOS logic devices. Specifically, the SN74LVC4245APWR is designed to interface between different logic systems with varying voltage levels, and it is available in a TSSOP (Thin Shrink Small Outline Package).
Package Information:
Package Type: TSSOP (Thin Shrink Small Outline Package) Pin Count: 20 pinsThe detailed functionality of each pin in the SN74LVC4245APWR package, as well as the circuit principle and operation, is provided below.
Pin Function Specifications:
Pin Number Pin Name Pin Description 1 A1 Data input/output pin for bus A. 2 A2 Data input/output pin for bus A. 3 A3 Data input/output pin for bus A. 4 A4 Data input/output pin for bus A. 5 A5 Data input/output pin for bus A. 6 A6 Data input/output pin for bus A. 7 A7 Data input/output pin for bus A. 8 A8 Data input/output pin for bus A. 9 DIR Direction control input. Determines the direction of data flow between buses A and B. 10 GND Ground pin. 11 B1 Data input/output pin for bus B. 12 B2 Data input/output pin for bus B. 13 B3 Data input/output pin for bus B. 14 B4 Data input/output pin for bus B. 15 B5 Data input/output pin for bus B. 16 B6 Data input/output pin for bus B. 17 B7 Data input/output pin for bus B. 18 B8 Data input/output pin for bus B. 19 VCC Supply voltage pin. 20 OE (Output Enable) Active low output enable input. When low, allows the data to flow through to the output pins.Circuit Principle:
The SN74LVC4245APWR is used as a bus transceiver between two buses (A and B) and allows data to be transmitted in both directions. It is controlled by a direction input (DIR) and an output enable (OE) pin. The logic state of the direction pin determines whether data is transferred from bus A to bus B or from bus B to bus A. The output enable (OE) pin must be low to enable output on the bus, and high to disable output and place the bus in a high-impedance state.
20 Common FAQs About SN74LVC4245APWR:
What is the function of the DIR pin on the SN74LVC4245APWR? The DIR pin controls the direction of data flow between buses A and B. When DIR is low, data flows from A to B; when DIR is high, data flows from B to A.
What happens when the OE pin is high? When OE (Output Enable) is high, the output is disabled, and the transceiver enters a high-impedance state. No data will flow out of the device.
What is the voltage range of the SN74LVC4245APWR? The operating voltage range for SN74LVC4245APWR is from 2.0V to 5.5V.
Can this device operate at 3.3V? Yes, the SN74LVC4245APWR can operate at a 3.3V supply voltage.
What is the maximum data rate the SN74LVC4245APWR can handle? The device can operate at high-speed data rates of up to 250 Mbps.
What is the purpose of the GND pin on the SN74LVC4245APWR? The GND pin is used to connect the device to the ground of the system for proper operation.
How do I connect the SN74LVC4245APWR to microcontrollers? You can connect the transceiver's A and B data pins to the microcontrollers' I/O ports, and use the DIR and OE pins for control logic.
How do I calculate the propagation delay for the device? The propagation delay is provided in the datasheet as a typical value, but it is around 3.4 ns at 3.3V and 5V supply voltage.
Can I use this device for interfacing different voltage levels? Yes, the SN74LVC4245APWR can interface logic signals between devices with different voltage levels (e.g., 5V logic to 3.3V logic).
What is the significance of the "APWR" part of the part number? The "APWR" indicates the package type, which is a 20-pin TSSOP (Thin Shrink Small Outline Package) with a wide lead pitch.
What is the function of the A1 to A8 pins on the device? These pins are the data input/output pins for bus A, and data can be sent or received from these pins depending on the direction control.
How can I use the device in a bidirectional communication system? You can use the device in a system where two buses need to share data in both directions by controlling the DIR and OE pins accordingly.
What is the importance of the VCC pin on the SN74LVC4245APWR? The VCC pin provides the supply voltage to the device, typically between 2.0V and 5.5V.
What are the maximum output drive capabilities of the SN74LVC4245APWR? The device can drive outputs to 24 mA in both high and low states.
Is there any configuration needed for the DIR and OE pins? Yes, you must configure DIR to control the direction of data flow and set OE low to enable output data.
How should I handle unused pins? Unused pins should be either left floating or tied to a defined logic level, depending on the system requirements.
Can I use this device in a noisy environment? The SN74LVC4245APWR is designed with noise immunity and works well in standard industrial and consumer applications.
What is the typical Power consumption of the device? Power consumption varies with supply voltage and logic levels, but it typically consumes only a few milliwatts under normal conditions.
What kind of protection is built into the device for overvoltage conditions? The device is designed with protection diodes to handle minor voltage spikes but is not suitable for handling large overvoltage situations.
How can I interface multiple SN74LVC4245APWR devices together? Multiple devices can be connected in a daisy-chaining manner by appropriately connecting their A and B bus lines, while controlling their DIR and OE pins as needed.
This completes the detailed explanation of the SN74LVC4245APWR pin functions, circuit principles, and FAQs in a comprehensive manner.
