Overview
The SN55451BJG is a dual-peripheral driver from Texas Instruments, designed for use in systems that employ TTL logic. This device is part of the SN5545xB family, which is functionally interchangeable with and replaces the earlier SN75450 and SN75450A families. The SN55451BJG is characterized for operation over the full military temperature range of –55°C to 125°C, ensuring robust performance in a wide range of environments.
The device features dual AND logic gates with the output of the logic gates internally connected to the bases of the npn output transistors, providing high-speed switching and high-current drive capabilities. It is particularly useful in applications requiring high-voltage and high-current outputs from low-voltage logic inputs.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC (Supply Voltage) | 4.75 | 5 | 5.25 | V |
| VI (Input Voltage) | - | - | 5.5 | V |
| VO (Off-state Output Voltage) | - | - | 30 | V |
| IOK (Continuous Collector or Output Current) | - | - | 400 | mA |
| Peak Collector or Output Current (tw ≤10 ms, duty cycle ≤50%) | - | - | 500 | mA |
| TA (Operating Free-Air Temperature) | -55 | - | 125 | °C |
| tPLH (Propagation Delay Time, Low-to-High-Level Output) | 18 | 25 | - | ns |
| tPHL (Propagation Delay Time, High-to-Low-Level Output) | 26 | 35 | - | ns |
Key Features
- Characterized for use up to 300 mA
- High-voltage outputs up to 30 V
- No output latch-up at 20 V after conducting 300 mA
- High-speed switching
- Open-collector outputs
- Circuit flexibility for varied applications
- TTL-compatible diode-clamped inputs
- Standard supply voltages
Applications
- High-speed logic buffers
- Power drivers
- Lamp drivers
- LED drivers
- Line drivers
- Memory drivers
The SN55451BJG is typically used to drive high-voltage or high-current peripherals from an MCU or logic device that cannot tolerate these conditions. For example, it can drive an LED and a high-voltage peripheral simultaneously.
Q & A
- What is the operating temperature range of the SN55451BJG?
The SN55451BJG operates over the full military temperature range of –55°C to 125°C.
- What is the maximum continuous collector or output current for the SN55451BJG?
The maximum continuous collector or output current is 400 mA.
- What is the maximum off-state output voltage for the SN55451BJG?
The maximum off-state output voltage is 30 V.
- Does the SN55451BJG have TTL-compatible inputs?
- What are some common applications of the SN55451BJG?
- How should unused input channels be handled in the SN55451BJG?
Unused input channels should be connected to ground or VCC to prevent floating inputs and ensure the logic gate is in a known state.
- What is the recommended power supply configuration for the SN55451BJG?
The power supply can be any voltage between the minimum and maximum supply voltage rating, and a bypass capacitor (e.g., 0.1-µF) should be used on the VCC pin to prevent power disturbances.
- What are the propagation delay times for the SN55451BJG?
The propagation delay time for low-to-high-level output (tPLH) is typically 25 ns, and for high-to-low-level output (tPHL) it is typically 35 ns.
- Does the SN55451BJG have open-collector outputs?
- How should the layout be designed for the SN55451BJG?
The layout should use thin traces for the input due to low-current logic, separate the input channels to eliminate crosstalk, and use thick traces for the output to drive high currents.
