Overview
The AD7846JPZ-REEL is a 16-bit Digital-to-Analog Converter (DAC) produced by Analog Devices Inc. This device is constructed using the LC2MOS process and features VREF+ and VREF− reference inputs along with an on-chip output amplifier. The AD7846 can be configured to provide unipolar output ranges (0 V to +5 V, 0 V to +10 V) or bipolar output ranges (±5 V, ±10 V). It utilizes a segmented architecture to ensure 16-bit monotonicity and excellent integral linearity due to the tight matching between the input offset voltages of the two buffer amplifiers.
The device includes a comprehensive microprocessor interface with 16 data I/O pins and control lines (CS, R/W, LDAC, and CLR), enabling functions such as readback and simultaneous updating of DACs in multi-DAC systems. The AD7846 is available in 28-lead plastic, ceramic, and PLCC packages.
Key Specifications
| Parameter | Value | Unit | Test Conditions/Comments |
|---|---|---|---|
| Resolution | 16 bits | ||
| Output Range | 0 V to +5 V, 0 V to +10 V (unipolar), ±5 V, ±10 V (bipolar) | V | |
| Integral Linearity Error (INL) | ±0.5 LSB | LSB | |
| Digital Input High Voltage (VIH) | 2.4 V min | V | |
| Digital Input Low Voltage (VIL) | 0.8 V max | V | |
| Input Current (IIN) | ±10 μA max | μA | |
| Input Capacitance (CIN) | 10 pF max | pF | |
| Output Resistance | 0.3 Ω typ | Ω | To 0 V |
| Short Circuit Current | ±25 mA typ | mA | To 0 V or any power supply |
| VDD Voltage Range | +11.4 V to +15.75 V | V | |
| VSS Voltage Range | −14.25 V to −15.75 V | V | |
| VCC Voltage Range | +4.75 V to +5.25 V | V |
Key Features
- 16-Bit Monotonicity: Guaranteed monotonicity over temperature, ideal for closed-loop applications.
- Readback Function: Ability to read back the DAC register contents, useful in Automated Test Equipment (ATE) applications.
- Comprehensive Microprocessor Interface: Includes 16 data I/O pins and control lines (CS, R/W, LDAC, and CLR) for writing to and reading from the I/O latch.
- Simultaneous Updating: LDAC line allows simultaneous updating of DACs in multi-DAC systems.
- Reset Function: CLR line resets the contents of the DAC latch to 00…000 or 10…000 depending on the state of R/W.
- Segmented Architecture: Ensures 16-bit resolution with the four MSBs selecting one of the segments in a 16-resistor string, and both taps buffered by amplifiers and fed to a 12-bit DAC.
- Package Options: Available in 28-lead plastic, ceramic, and PLCC packages.
Applications
- Closed-Loop Systems: Ideal due to its guaranteed 16-bit monotonicity over temperature.
- Automated Test Equipment (ATE): The readback function is particularly useful in ATE applications.
- Multi-DAC Systems: The LDAC line allows for simultaneous updating of multiple DACs.
- Industrial Control Systems: Suitable for applications requiring precise voltage output and control.
- Medical Devices: Can be used in medical equipment that requires high precision and reliability.
Q & A
- What is the resolution of the AD7846JPZ-REEL DAC?
The AD7846JPZ-REEL has a resolution of 16 bits.
- What are the possible output ranges for the AD7846JPZ-REEL?
The output ranges can be configured as unipolar (0 V to +5 V, 0 V to +10 V) or bipolar (±5 V, ±10 V).
- What is the significance of the segmented architecture in the AD7846JPZ-REEL?
The segmented architecture ensures 16-bit monotonicity and excellent integral linearity by using a combination of a 16-resistor string and a 12-bit DAC.
- What is the purpose of the readback function in the AD7846JPZ-REEL?
The readback function allows reading back the DAC register contents, which is useful in Automated Test Equipment (ATE) applications.
- How can the DAC output be reset in the AD7846JPZ-REEL?
The CLR line can reset the contents of the DAC latch to 00…000 or 10…000 depending on the state of R/W, allowing the DAC output to be reset to 0 V in both unipolar and bipolar configurations.
- What are the package options available for the AD7846JPZ-REEL?
The AD7846JPZ-REEL is available in 28-lead plastic, ceramic, and PLCC packages.
- What is the typical output resistance of the AD7846JPZ-REEL?
The typical output resistance is 0.3 Ω.
- What is the maximum short circuit current of the AD7846JPZ-REEL?
The maximum short circuit current is ±25 mA.
- What are the voltage ranges for VDD, VSS, and VCC in the AD7846JPZ-REEL?
VDD: +11.4 V to +15.75 V, VSS: −14.25 V to −15.75 V, VCC: +4.75 V to +5.25 V.
- What is the significance of the LDAC line in the AD7846JPZ-REEL?
The LDAC line allows for simultaneous updating of DACs in multi-DAC systems.
