DAC7801LP Equivalent & Substitute Parts

Part Overview

The DAC7801LP is a 12-bit digital-to-analog converter manufactured by Texas Instruments, designed for data acquisition applications requiring dual D/A conversion with current output. The device operates with 5V analog and digital supply voltages and features an R-2R architecture with 800ns settling time. The DAC7801LP is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing system support. Substitute parts must maintain functional compatibility while accommodating packaging and performance variations.

Substiute Parts

DAC7801LP

Texas InstrumentsIn Stock: 1951DAC7801LP Datasheet

Current PartRFQ

DAC7822IRTAT

Texas InstrumentsIn Stock: 1402DAC7822IRTAT Datasheet

MFR RecommendedRFQ

DAC7800LU

Texas InstrumentsIn Stock: 1727DAC7800LU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the DAC7801LP is determined by the following core electrical and mechanical parameters:

• 12-bit resolution with dual D/A converters
• Current output, unbuffered configuration
• External reference requirement
• R-2R architecture
• Parallel data interface
• 5V supply voltage operation

The substitute parts identified are DAC7800LU and DAC7822IRTAT. Both maintain the 12-bit, dual-converter architecture and R-2R topology. However, substitution involves trade-offs in packaging, mounting technology, settling time, and supply voltage flexibility. The DAC7800LU provides a direct functional match with modified packaging, while the DAC7822IRTAT offers enhanced performance characteristics with expanded supply voltage range and faster settling time, requiring design-level evaluation for compatibility.

Parameter Comparison

Engineering Selection Recommendations

DAC7800LU is suitable for applications requiring direct functional equivalence with the DAC7801LP. This substitute maintains identical settling time (800ns), supply voltage requirements (5V), and linearity specifications (±0.5/±1 LSB). The primary design consideration is the transition from through-hole 24-DIP packaging to surface-mount 16-SOIC packaging, which reduces board footprint and accommodates modern manufacturing processes. The data interface change from parallel to SPI requires firmware modification for control signal sequencing. The DAC7800LU is active product status, ensuring long-term availability and support.

DAC7822IRTAT provides enhanced performance characteristics suitable for applications benefiting from faster settling time (200ns) and extended operating temperature range (-40°C to 125°C). This substitute accepts expanded supply voltage range (2.5V to 5.5V), enabling operation in systems with variable power supplies. The 40-WQFN surface-mount package requires PCB layout redesign. Linearity specifications relax to ±1/±1 LSB, acceptable for applications not requiring the original ±0.5 LSB INL specification. The DAC7822IRTAT is active product status with current manufacturing support.

Both substitutes are ROHS3 compliant and maintain the R-2R architecture and dual-converter configuration of the original part. Selection depends on application-specific requirements for settling time, supply voltage flexibility, temperature range, and PCB integration strategy.

Frequently Asked Questions (FAQ)

Q: Can DAC7800LU directly replace DAC7801LP without firmware changes?

A: No. While both devices are 12-bit dual D/A converters with identical settling time and supply voltage, the DAC7800LU uses SPI data interface instead of parallel. Control logic and timing sequences must be modified to accommodate serial communication protocol.

Q: What are the packaging implications of substituting DAC7801LP with DAC7800LU?

A: The DAC7801LP uses through-hole 24-DIP packaging suitable for breadboard and legacy PCB designs. The DAC7800LU requires surface-mount 16-SOIC technology, necessitating PCB redesign with appropriate solder pads and reflow soldering processes. The footprint is significantly smaller, reducing board area.

Q: Is DAC7822IRTAT compatible with 5V-only systems?

A: Yes. The DAC7822IRTAT accepts supply voltages from 2.5V to 5.5V, making it compatible with 5V systems. However, the expanded voltage range does not provide backward compatibility with systems requiring fixed 5V operation; the device will function correctly at 5V within specification.

Q: What is the significance of the settling time difference between DAC7801LP (800ns) and DAC7822IRTAT (200ns)?

A: Settling time defines the duration required for the output to stabilize within specified accuracy after a digital input change. The DAC7822IRTAT settles four times faster, enabling higher update rates and faster system response in time-critical applications. Applications with slower update requirements are unaffected by this difference.

Q: Are all three parts ROHS3 compliant?

A: Yes. DAC7801LP, DAC7800LU, and DAC7822IRTAT are all ROHS3 compliant, meeting environmental and hazardous substance restrictions for electronic components.

Q: What is the impact of differential output on DAC7822IRTAT?

A: The DAC7822IRTAT includes differential output capability, while DAC7801LP and DAC7800LU provide single-ended current output. Differential output enables noise rejection in long-distance signal transmission and differential amplifier configurations. Single-ended applications can use one output terminal, leaving the differential output unused.

Q: Which substitute is recommended for new designs?

A: Selection depends on application requirements. For systems requiring parallel interface and legacy through-hole compatibility, DAC7800LU is appropriate. For new designs benefiting from faster settling time, extended temperature range, and surface-mount integration, DAC7822IRTAT is suitable. Both are active products with manufacturer support.