Overview
The AD7545AKR-REEL7, produced by Analog Devices Inc., is a 12-bit CMOS multiplying Digital-to-Analog Converter (DAC) with internal data latches. This component is an improved version of the industry-standard AD7545 and is designed to offer high precision and versatility in various digital-to-analog conversion applications. It operates with a single 12-bit-wide word input under the control of Chip Select (CS) and Write (WR) signals, making it compatible with both 8-bit and 16-bit microprocessors.
Key Specifications
| Parameter | Value | Units | Conditions |
|---|---|---|---|
| Resolution | 12 | Bits | - |
| Relative Accuracy | ±1/2 LSB max | - | All Grades |
| Differential Nonlinearity | ±1 LSB max | - | All Grades |
| Input High Voltage (VIH) | 2.4 V min to 13.5 V max | V | - |
| Input Low Voltage (VIL) | 0.8 V max to 1.5 V max | V | - |
| Input Current (IIN) | ±1 µA max to ±10 µA max | µA | VIN = 0 or VDD |
| Input Capacitance (DB0–DB11) | 5 pF max | pF | VIN = 0 |
| Output Capacitance (COUT1) | 70 pF max to 200 pF max | pF | DB0–DB11 = 0 V or VDD, WR, CS = 0 V |
| Chip Select to Write Setup Time (tCS) | 180 ns min to 380 ns min | ns | - |
| Write Pulse Width (tWR) | 160 ns min to 400 ns min | ns | tCS ≥ tWR, tCH ≥ 0 |
| Supply Voltage (VDD) | +5 V to +15 V | V | - |
Key Features
- High Resolution: 12-bit resolution providing precise digital-to-analog conversion.
- Internal Data Latches: Allows for single 12-bit-wide word input under CS and WR control signals.
- Compatibility with Microprocessors: Directly interfaces with both 8-bit and 16-bit microprocessors.
- Low Power Consumption: Dissipates less than 0.5 mW for VDD = +5 V.
- Flexible Output Configuration: Output voltage ranges can be adjusted by changing external resistors.
- Constant Input Impedance: The reference input impedance is constant, allowing for direct connection to a reference voltage or current source.
Applications
- Industrial Control Systems: Used in precision control and measurement systems.
- Medical Devices: Suitable for medical equipment requiring high accuracy and reliability.
- Aerospace and Defense: Applied in various military and aerospace applications due to its robust specifications.
- Automotive Systems: Used in automotive control systems for precise analog output generation.
- Test and Measurement Equipment: Utilized in calibration and testing equipment for its high precision.
Q & A
- What is the resolution of the AD7545AKR-REEL7?
The AD7545AKR-REEL7 has a 12-bit resolution.
- What is the operating supply voltage range for the AD7545AKR-REEL7?
The operating supply voltage range is from +5 V to +15 V.
- How does the AD7545AKR-REEL7 interface with microprocessors?
It interfaces directly with both 8-bit and 16-bit microprocessors using standard CS and WR control signals.
- What is the typical power consumption of the AD7545AKR-REEL7?
It dissipates less than 0.5 mW for VDD = +5 V.
- Can the output voltage range of the AD7545AKR-REEL7 be adjusted?
Yes, the output voltage range can be adjusted by changing external resistors (R1, R2, and R4).
- What is the significance of the constant input impedance at the VREF pin?
The constant input impedance allows the reference input to be driven directly by a reference voltage or current source without the need for a buffer amplifier, although a buffer may be necessary for applications with wide temperature variations.
- How can digital glitches be minimized in the AD7545AKR-REEL7?
Digital glitches can be minimized by screening the analog pins and ensuring that the write pulse (WR) only occurs when valid data is present on the data bus.
- What are the typical applications of the AD7545AKR-REEL7?
It is used in industrial control systems, medical devices, aerospace and defense, automotive systems, and test and measurement equipment.
- What is the significance of the Chip Select to Write Setup Time (tCS) and Write Pulse Width (tWR)?
tCS and tWR are critical timing parameters that ensure proper data latching and conversion; tCS must be greater than or equal to tWR, and tWR must be at least 160 ns to 400 ns depending on the version.
- How does the AD7545AKR-REEL7 handle invalid data during a write cycle?
Invalid data can be avoided by retiming the write pulse (WR) to ensure it only occurs when valid data is present on the data bus.
