Overview
The SN74AHC573DW is an octal transparent D-type latch produced by Texas Instruments. This device is designed to operate within a wide voltage range of 2 V to 5.5 V, making it versatile for various applications. When the latch-enable (LE) input is high, the Q outputs follow the data (D) inputs. When LE is low, the Q outputs are latched at the logic levels of the D inputs. The device features 3-state outputs that can be placed in a high-impedance state, allowing them to drive bus lines without significant loading or driving.
Key Specifications
| Parameter | Unit | Min | Max |
|---|---|---|---|
| VCC (Supply Voltage) | V | 2 | 5.5 |
| VIH (High-level Input Voltage) | V | 1.5 (VCC = 2 V) 2.1 (VCC = 3 V) 3.85 (VCC = 5.5 V) | 1.5 (VCC = 2 V) 2.1 (VCC = 3 V) 3.85 (VCC = 5.5 V) |
| VIL (Low-level Input Voltage) | V | 0.5 (VCC = 2 V) 0.9 (VCC = 3 V) 1.65 (VCC = 5.5 V) | 0.5 (VCC = 2 V) 0.9 (VCC = 3 V) 1.65 (VCC = 5.5 V) |
| IOH (High-level Output Current) | mA | -50 (VCC = 2 V) -4 (VCC = 3.3 V ± 0.3 V) -8 (VCC = 5 V ± 0.5 V) | -50 (VCC = 2 V) -4 (VCC = 3.3 V ± 0.3 V) -8 (VCC = 5 V ± 0.5 V) |
| IOL (Low-level Output Current) | mA | 50 (VCC = 2 V) 4 (VCC = 3.3 V ± 0.3 V) 8 (VCC = 5 V ± 0.5 V) | 50 (VCC = 2 V) 4 (VCC = 3.3 V ± 0.3 V) 8 (VCC = 5 V ± 0.5 V) |
| TA (Operating Free-Air Temperature) | °C | -40 | 125 |
| RθJA (Junction-to-Ambient Thermal Resistance) | °C/W | 81.1 (DW package) |
Key Features
- Wide operating voltage range: 2 V to 5.5 V.
- 3-state outputs directly drive bus lines.
- Latch-up performance exceeds 250 mA per JESD 17.
- Allows down voltage translation: Inputs accept voltages up to 5.5 V.
- Slow edges reduce output ringing.
- Buffered output-enable (OE) input for high-impedance state control.
Applications
- Servers.
- PCs and Notebooks.
- Network Switches.
- Wearable Health and Fitness Devices.
- Telecom Infrastructures.
- Electronic Points of Sale.
Q & A
- What is the operating voltage range of the SN74AHC573DW?
The operating voltage range is from 2 V to 5.5 V. - What is the function of the latch-enable (LE) input?
When the LE input is high, the Q outputs follow the data (D) inputs. When LE is low, the Q outputs are latched at the logic levels of the D inputs. - What is the purpose of the 3-state outputs?
The 3-state outputs can be placed in a high-impedance state, allowing them to drive bus lines without significant loading or driving. - What is the significance of slow edges in this device?
Slow edges reduce output ringing, minimizing overshoot and undershoot on the outputs. - What are the typical applications of the SN74AHC573DW?
Typical applications include servers, PCs and notebooks, network switches, wearable health and fitness devices, telecom infrastructures, and electronic points of sale. - How does the device handle input voltages above VCC?
The inputs accept voltages up to 5.5 V, allowing down voltage translation to the VCC level. - What is the thermal resistance of the DW package?
The junction-to-ambient thermal resistance (RθJA) for the DW package is 81.1 °C/W. - What are the recommended operating conditions for the device?
The device operates over a temperature range of -40°C to 125°C and has specific voltage and current limits as detailed in the specifications. - How does the output-enable (OE) input affect the device?
The OE input can place the outputs in either a normal logic state or the high-impedance state without affecting the internal operations of the latches. - What precautions should be taken during power-up or power-down?
OE should be tied to VCC through a pull-up resistor to ensure the high-impedance state during power-up or power-down).
