Overview
The NA556DR, produced by Texas Instruments, is a dual precision timer integrated circuit. It provides two independent timing circuits, each similar to the NA555, NE555, SA555, or SE555 type, within a single package. This device is designed for general-purpose timing applications and can operate in both astable and monostable modes. The timing intervals are controlled by external resistor-capacitor (RC) networks, allowing for flexible and precise timing configurations.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC Supply Voltage | 4.5 | - | 16 | V |
| Operating Free-Air Temperature | 0 | - | 70 | °C |
| Output Current | - | - | ±200 | mA |
| Threshold Voltage Level (VCC = 15V) | 8.8 | 10 | 11.2 | V |
| Trigger Voltage Level (VCC = 15V) | 4.5 | 5 | 5.6 | V |
| Reset Voltage Level | 0.3 | 0.7 | 1 | V |
| Low-Level Output Voltage (VCC = 15V, IOL = 10mA) | 0.1 | 0.25 | - | V |
| High-Level Output Voltage (VCC = 15V, IOH = -100mA) | 12.75 | 13.3 | - | V |
Key Features
- Two precision timing circuits per package, similar to NA555, NE555, SA555, or SE555 types.
- Astable or monostable operation modes.
- TTL-compatible output can sink or source up to 200mA.
- Active pullup or pulldown capabilities.
- External resistor-capacitor (RC) timing control with adjustable trigger and threshold levels.
- Reset input overrides all other inputs for initiating a new timing cycle.
Applications
- Precision timers from microseconds to hours.
- Pulse-shaping circuits.
- Missing-pulse detectors.
- Pulse-width modulators.
- Pulse-position modulators.
- Sequential timers.
- Pulse generators.
- Frequency dividers.
- Application timers.
- Industrial controls.
Q & A
- What is the NA556DR used for?
The NA556DR is used for general-purpose timing applications, providing two independent timing circuits in a single package.
- What are the operating modes of the NA556DR?
The NA556DR can operate in both astable and monostable modes.
- What is the maximum output current of the NA556DR?
The NA556DR can sink or source up to 200mA.
- How are the timing intervals controlled in the NA556DR?
The timing intervals are controlled by external resistor-capacitor (RC) networks.
- What is the role of the reset input in the NA556DR?
The reset input overrides all other inputs to initiate a new timing cycle.
- What are some common applications of the NA556DR?
Common applications include precision timers, pulse-shaping circuits, missing-pulse detectors, pulse-width modulators, and industrial controls.
- What is the supply voltage range for the NA556DR?
The supply voltage range is from 4.5V to 16V.
- What is the operating temperature range for the NA556DR?
The operating temperature range is from 0°C to 70°C.
- How does the trigger voltage level affect the NA556DR?
The trigger voltage level sets the internal latch when it falls below a certain threshold, typically around one-third of the supply voltage.
- Can the NA556DR be used in high-frequency applications?
While it can be used in high-frequency applications, it is recommended to use it at frequencies of 100kHz or below to avoid distortion. For higher frequencies, consider using the TLC556 LinCMOS™ Timer.
