ADS774JP - 12-Bit 125 kSPS SAR ADC | Texas Instruments
MPN: ADS774JP ✗ End of LifeADS774JP Overview
An SAR ADC is a sampling data-conversion device that compares the sampled input voltage against an internal capacitor DAC during each conversion. The ADS774JP uses a capacitor array implemented in low-power CMOS technology to perform successive comparisons. Its integrated sampling and microprocessor interface simplify analog acquisition while reducing the external component count compared with older converter families such as ADC574, ADC674, and ADC774.
The principal operating characteristics include 12-bit resolution, one analog input channel, 8.5 microseconds maximum conversion time, and operation from a single +5 V supply. According to the manufacturer datasheet, the ADS774 family can replace ADC574, ADC674, and ADC774 models in most applications while providing internal sampling and lower power consumption. These characteristics make it suitable for industrial data acquisition, process control, instrumentation, and microprocessor-based measurement systems.
The internal sampling architecture eliminates a separate sample-and-hold circuit in most applications. The parallel interface provides direct connection to microprocessor or microcontroller input ports, allowing converted codes to be read through digital bus lines. The converter is intended for designs requiring repeatable single-ended or bipolar acquisition rather than the throughput of very high-speed pipeline ADCs.
Designers should use the manufacturer pin-description table and application information when assigning PCB signals and selecting interface logic. Particular attention is required to input range, reference behavior, acquisition timing, digital bus timing, and power-supply bypassing. The ADS774JP is listed as obsolete by a product listing, so engineers should verify lifecycle status and replacement availability before starting a new production design.
This page combines the principal ADS774JP operating characteristics, verified package information, lifecycle context, and practical application guidance with a restrained drop-in comparison approach. It emphasizes engineering suitability rather than treating related converter models as interchangeable without checking their exact pinout, input architecture, interface timing, and acquisition requirements.
Drop-in alternatives for ADS774JP — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ADS774JP (same form factor and footprint) — differing in Architecture, Supply Voltage, Mounting Type, Package, Clock.
ADS774JEG4
✅ Drop-InContact for price
View Datasheet →ADS774JU
✅ Drop-InContact for price
View Datasheet →MAX174ACPI+
✅ Drop-In📋 Reference alternative (not in catalog)
ADS774JP Maximum Ratings & Electrical Characteristics
| Resolution | 12 bit |
| Converter Type | Successive approximation ADC (SAR) |
| Number of Analog Input Channels | 1 channel |
| Maximum Sampling Rate | 125 kSPS |
| Maximum Conversion Time | 8.5 us |
| Input Voltage Range | Unipolar or bipolar input |
| Reference | Internal reference |
| Digital Interface | Parallel microprocessor-compatible interface |
| Supply Voltage | +5 V single supply |
| Internal Architecture | Capacitor DAC (CDAC) implemented in low-power CMOS |
| Sampling Circuit | Internal sampling |
| Clock | Internal clock |
| Package | 28-pin PDIP |
| Mounting Type | Through-hole |
| Analog Input Type | Single-ended or differential |
ADS774JP 28-pin pdip Pin Configuration Guide
Pin configuration for ADS774JP (28-pin pdip package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for ADS774JP.
Refer to the datasheet for full pin configuration.
Typical Applications
ADS774JP is suitable for 6 applications: Industrial Process Measurement, Microprocessor Data-Acquisition System, Laboratory Instrumentation, Embedded Control and Monitoring, Power-Supply Feedback Monitoring, Legacy Equipment Maintenance.
Industrial Process Measurement
The ADS774JP suits process-control channels that convert a slowly changing pressure, temperature, or level signal into a 12-bit digital value for a microprocessor. Its 125 kSPS maximum sampling rate is substantially faster than most process-control loops require, while internal sampling, reference, and clock functions simplify analog front-end design. A unipolar input can be used for sensor outputs referenced to ground, or the input stage can support bipolar instrumentation signals. Board designers should keep high-impedance sources short, provide stable reference and supply bypassing, and place the converter close enough to minimize pickup on the analog input. Verify the complete input range and common-mode requirements in the manufacturer datasheet before scaling the sensor signal.
Recommended
Microprocessor Data-Acquisition System
The ADS774JP provides a practical parallel-interface ADC front end for a microprocessor or microcontroller-based acquisition system. At 12 bits and 125 kSPS, it suits instrumentation that gathers multiple slow analog channels through multiplexing rather than simultaneous high-speed sampling. Its internal sampling and clock reduce the need for a separate sample-and-hold device and external conversion clock, while the parallel bus allows converted data to be read through digital port lines. The acquisition controller should observe the conversion timing and bus-control signals shown in the datasheet. Grounding and decoupling remain important because the converter shares a board with digital logic and switching regulators.
Recommended
Laboratory Instrumentation
The ADS774JP can serve as the conversion stage in laboratory measurement equipment that translates an analog input into a 12-bit code for display, logging, or closed-loop control. The internal reference and single +5 V supply help reduce the number of support components, while the 8.5 microsecond maximum conversion time supports responsive single-channel readings. For bench instruments, use a shielded analog front end, a clean low-noise reference path, and separated return-current routing to prevent digital switching activity from shifting the conversion result. If the instrument must resolve very small signals, verify the input noise and accuracy limits in the manufacturer datasheet rather than relying on nominal resolution alone.
Recommended
Embedded Control and Monitoring
The ADS774JP is appropriate for embedded equipment that monitors one analog process variable and reports it through a host processor. Its single-channel architecture avoids the power and routing overhead of a wide multiplexed converter, and the microprocessor-compatible interface supports straightforward code acquisition. The 125 kSPS capability permits oversampling relative to a slow control loop, although the implementation should account for the ADC’s actual bandwidth, conversion interval, and acquisition requirements. A practical design can use the MCU for configuration, filtering, alarms, and actuator decisions while the ADS774JP performs the initial conversion. Firmware should perform input settling before each conversion and validate data against the digital interface timing diagram.
Recommended
Power-Supply Feedback Monitoring
The ADS774JP can monitor an analog feedback or output rail in a power-supply control system when the voltage is conditioned into its supported input range. The 12-bit code provides enough resolution for supervisory thresholds and trend tracking in many non-precision applications, while the single +5 V supply matches commonly available control electronics. Sampling at 125 kSPS is fast enough to capture supply transients when the associated analog front end and signal path have suitable bandwidth. Designers should use isolated or appropriately rated measurement methods when the monitored rail exceeds the converter’s input limits. A differential input configuration and careful common-mode analysis can reduce errors in high-side measurements, but every protection component must preserve accuracy and transient response.
Recommended
Legacy Equipment Maintenance
The ADS774JP is most practical in maintenance programs that reproduce the function of an existing ADS774-family board or a legacy converter design using a 28-PDIP footprint. The 12-bit, 125 kSPS SAR architecture and parallel interface support direct board-level substitution when the original schematic and pin mapping match. Before installation, compare the full ordering suffix, temperature grade, reference behavior, input configuration, and acquisition timing of the installed device. The part is listed as obsolete, so procurement should focus on traceable inventory and documented inspection rather than assuming long-term repeatability. For new production equipment, a supported converter with verified timing and pin compatibility is generally the lower-risk choice.
Recommended
Recommended Products Summary
Engineering reference data for ADS774JP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADS774JE | ADS774JU | MAX174ACPI+ |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Maxim Integrated |
| Package | 28-pin PDIP | 28-pin PDIP | 28-pin PDIP | 28-pin PDIP |
Key Differentiators
- Faster maximum conversion time than the identified cross-brand substitute (vs MAX174ACPI+)
- Same converter performance within the ADS774 family (vs ADS774JE)
- Internal sampling, reference, and clock integration (vs ADS774JU)
Design Notes
Route the analog input directly to the ADS774JP with a short trace and place the associated input-network components close to the converter. Keep digital output traces away from the analog input and reference paths to minimize capacitive coupling. Use a common ground plane with careful separation of analog and digital return currents, and follow the manufacturer application diagram for supply bypassing and input-reference layout.
Decouple the +5 V supply near the converter pins and keep the power trace sufficiently wide for the converter’s supply-current transients. Place the capacitor on the same board side as the device and connect it through a short ground path. Confirm the recommended capacitor value and stability configuration in the manufacturer datasheet, especially if the supply is shared with switching circuitry or a long harness.
Do not assume that every legacy ADC with a 28-pin package is electrically interchangeable. Before replacing ADS774JP, verify input range and polarity, reference connection, conversion timing, read-data control sequence, logic levels, acquisition settling, and temperature grade. The MAX174ACPI+ is described as compatible in most 28-DIP configurations, but its 10 microsecond conversion time differs from the 8.5 microsecond ADS774JP maximum and may affect sampling timing.
Treat the parallel data and control interface as a synchronous bus. Use the manufacturer timing diagram to determine when output data may be sampled and when the converter may begin another conversion. Account for propagation delay through the processor, address decoding, and any level-shifting components. If the bus is long or heavily loaded, buffer the signals and keep clock or control routing away from sensitive analog nodes.
Compliance Information
The exact-suffix RoHS, REACH, lead-free, halogen-free, and conflict-minerals declarations were not established. AEC-Q100 is not applicable to this general-purpose data-conversion device based on its stated application class.