Overview
The TLC7225CDWRG4, produced by Texas Instruments, is a quadruple 8-bit digital-to-analog converter (DAC) integrated circuit. This device features four independent 8-bit voltage-output DACs, each with its own output buffer amplifier and interface logic. The TLC7225 is designed for high-performance applications, offering microprocessor compatibility, TTL/CMOS compatibility, and the ability to operate with either single or dual power supplies. The device is fabricated using the LinBiCMOS process, allowing for the integration of high-speed digital logic and precision analog circuits on the same chip.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VDD) | 11.4 | - | 16.5 | V |
| Supply Voltage (VSS) | 0 | - | -5 | V |
| Reference Voltage (Vref) | 2 | - | VDD - 4 | V |
| Resolution | - | - | 8 Bits | - |
| Total Unadjusted Error | - | - | ±2 LSB | - |
| Settling Time to 1/2 LSB (Positive Full Scale) | - | - | 5 µs | - |
| Settling Time to 1/2 LSB (Negative Full Scale) | - | - | 20 µs | - |
| Output Current Capability | - | - | Up to 5 mA | - |
| Operating Temperature Range (C suffix) | 0 | - | 70 | °C |
| Operating Temperature Range (I suffix) | -25 | - | 85 | °C |
Key Features
- Four independent 8-bit voltage-output digital-to-analog converters (DACs) with output buffer amplifiers.
- Microprocessor compatible with TTL/CMOS-compatible digital inputs.
- Single supply operation possible, with enhanced performance using dual supplies.
- Simultaneous update facility for all four DACs using the LDAC control input.
- Double register-buffering for each DAC, allowing for transparent input registers and DAC registers.
- Capable of driving up to 5 mA of output current and capacitive loads of 3300 pF.
- Direct bipolar operation without an external level-shift amplifier by biasing AGND to VSS.
- Compact 24-terminal SOIC package, optimizing board layout and reducing board space requirements.
Applications
- Process control systems requiring multiple analog outputs.
- Automatic test equipment (ATE) for generating precise analog signals.
- Automatic calibration of large system parameters such as gain and offset.
- Industrial automation and control systems.
- Medical and scientific instruments requiring high-precision analog outputs.
Q & A
- What is the resolution of the TLC7225 DACs?
The TLC7225 features four 8-bit DACs, each with a resolution of 8 bits.
- What are the operating temperature ranges for the TLC7225?
The TLC7225C is characterized for operation from 0°C to 70°C, and the TLC7225I is characterized for operation from –25°C to 85°C.
- Can the TLC7225 operate with a single power supply?
Yes, the TLC7225 can operate with a single power supply, although dual supply operation enhances performance in some parameters.
- What is the maximum output current capability of the TLC7225?
The output buffer amplifiers of the TLC7225 can drive up to 5 mA of output current.
- How does the TLC7225 achieve direct bipolar operation?
The TLC7225 can achieve direct bipolar operation by biasing AGND to VSS, eliminating the need for external level-shift amplifiers.
- What is the significance of the LDAC control input in the TLC7225?
The LDAC control input allows for the simultaneous update of all four DACs, enabling synchronized analog output changes.
- What are the typical applications of the TLC7225?
The TLC7225 is commonly used in process control, automatic test equipment, and the automatic calibration of system parameters.
- How does the TLC7225 handle digital input compatibility?
The TLC7225 digital inputs are compatible with both TTL and 5-V CMOS levels, ensuring versatility in microprocessor interfaces.
- What is the impact of VSS on the output sink capability and settling time of the TLC7225?
Tying VSS to –5 V maintains the full sink capability of 400 µA over the full output voltage range and improves negative-going settling time compared to single-supply operation.
- How does the TLC7225 manage channel-to-channel isolation?
The TLC7225 requires careful board layout and grounding to minimize analog crosstalk between the four channels, with channel-to-channel isolation specified at 60 dB at 10 kHz.
