ADS774JU - 12-Bit 125 kSPS SAR ADC | Texas Instruments
MPN: ADS774JU ✓ نشطADS774JU نظرة عامة
An ADC is the electronic interface that converts an analog voltage into a numeric value for processing, measurement, or control. The ADS774 belongs to the successive-approximation ADC family, whose internal capacitor-array DAC compares a sampled input against successive trial voltages. Compared with flash and high-speed pipeline converters, this SAR architecture is appropriate for moderate-speed, high-resolution industrial instrumentation where a parallel microprocessor interface and integrated sampling simplify system design.
The ADS774JU's principal features include 12-bit resolution, one analog input, a 28-pin SOIC package, and a 125 kSPS nominal conversion rate. According to the manufacturer datasheet, it replaces ADC574, ADC674, and ADC774 devices in most applications while adding internal sampling, lower power consumption, and single-supply operation. A maximum acquisition-and-conversion time of 8.5 µs supports process monitoring and general data-acquisition systems.
Internally, the converter uses a low-power CMOS capacitor-array CDAC. Its microprocessor-compatible output uses three-state logic, allowing the data bus to share access with other bus devices. The provided ordering information identifies the JU temperature grade as operating from -40 °C to +85 °C. The SOIC (DW) package provides 28 pins and is suitable for conventional through-hole board assembly, socketed prototyping, and legacy industrial control systems.
Typical applications include industrial process-control loops, instrumentation, data acquisition, digital voltmeter and panel-meter designs, and legacy microprocessor interfaces. The device is particularly relevant when a system needs a direct replacement for older ADC574-, ADC674-, or ADC774-based hardware and requires internal sample-and-hold behavior rather than an external sampling circuit.
Designers should verify the analog input range, reference accuracy, acquisition timing, and output-code format against the system requirements before replacing an older converter. Decoupling should be placed close to the supply pins, and unused digital outputs should be handled according to the manufacturer's bus and power-sequencing guidance.
This page consolidates the verified manufacturer and distributor information for the ADS774JU, distinguishes the few confirmed same-package drop-in options, and adds application guidance, parameter comparisons, and practical design considerations for engineers evaluating legacy data-conversion upgrades.
بدائل مباشرة لـ ADS774JU — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
ADS7820U
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
ADS774HIBDW
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
ADS774HIDW
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
ADS774JU الحدود القصوى والخصائص الكهربائية
| الدقة | 12 bit |
| معدل أخذ العينات | 125 kSPS |
| Acquisition and Conversion Time | 8.5 µs maximum over temperature |
| Analog Input Channels | 1 channel |
| Architecture | Successive-approximation ADC (SAR) |
| Internal Conversion Element | Capacitor-array CDAC |
| جهد التغذية | 4.5 V to 5.5 V |
| Input Range | ±10 V supported by internal scaling resistors |
| Output Interface | Microprocessor-compatible parallel output with three-state outputs |
| العلبة | 28-pin SOIC (DW) |
| نوع التركيب | Through-hole SOIC |
| درجة حرارة التشغيل | -40 °C to +85 °C |
| Reference and Clock | Internal |
| Sample-and-Hold | Internal sampling |
دليل تكوين أطراف ADS774JU 28-pin soic (dw)
تكوين الأطراف لـ ADS774JU (حزمة 28-pin soic (dw)). يتميز هذا المكوّن التناظري بأطراف الإدخال والإخراج وإمداد الطاقة. راجع ورقة بيانات الشركة المصنعة لتكوينات طرف إلغاء الإزاحة والتعويض والتمكين. مثالي لدوائر تكييف الإشارة والمضخمات.
لا تتوفر بيانات مفصلة لمخطط التوصيلات لـ ADS774JU.
راجع ورقة البيانات للحصول على تكوين الأطراف الكامل.
التطبيقات النموذجية
ADS774JU مناسب لـ 6 التطبيقs: Industrial Process Measurement, Legacy Data Acquisition Systems, Digital Panel Meters and Indicators, Precision Voltage Measurement, Instrumentation Signal Acquisition, Educational and Prototype Converters.
Industrial Process Measurement
ADS774JU fits industrial process-measurement loops that require a moderate-speed, 12-bit conversion result without a high-speed serial ADC. Its 125 kSPS nominal rate and 8.5 µs maximum acquisition-and-conversion time allow a controller to sample sensors, pressure transmitters, or transducer outputs more frequently than a slow integrating converter. The internal sample-and-hold circuit simplifies the front end, while the 4.5 V to 5.5 V single-supply operation supports legacy +5 V control hardware. Input protection, grounding, and calibration remain necessary because sensor signals and ADC accuracy are not determined by resolution alone.
موصى به
Legacy Data Acquisition Systems
ADS774JU is particularly suitable for maintaining or reproducing legacy data-acquisition equipment based on ADC574-, ADC674-, or ADC774-class interfaces. According to the Texas Instruments manufacturer datasheet, it is a drop-in replacement in most applications and adds internal sampling, lower power consumption, and single-supply operation. The 28-pin SOIC package and microprocessor-compatible three-state outputs support board-level replacement strategies. Engineers should still compare input polarity, output coding, conversion timing, and control signals because “most applications” does not guarantee compatibility in every custom analog or digital subsystem.
موصى به
Digital Panel Meters and Indicators
ADS774JU can serve as the measurement engine in digital panel meters, laboratory indicators, and process displays where a stable numeric representation of a bipolar input is required. Its 12-bit resolution provides 4096 discrete code levels, while the listed ±10 V input capability through internal scaling resistors simplifies compatibility with higher-level analog signals. The 125 kSPS rate is more than sufficient for typical human-readable meter refresh rates. Board designers should account for calibration, input overvoltage protection, reference accuracy, and grounding to ensure displayed values remain reproducible.
موصى به
Precision Voltage Measurement
ADS774JU is appropriate for precision voltage measurement modules that compare sensed process signals against thresholds or transmit measurements to a supervisory controller. Its 12-bit SAR architecture and internal sample-and-hold function provide a compact conversion path, while the 125 kSPS rate supports repeated measurements without requiring a separate sample-and-hold IC. For high-accuracy results, the analog frontend must provide low-noise reference conditioning, adequate settling time, and an input source impedance compatible with the acquisition network. Firmware can then apply offset, gain, and linearity calibration.
موصى به
Instrumentation Signal Acquisition
ADS774JU offers a practical conversion front end for instrumentation systems that need microprocessor-readable measurements from moderate-bandwidth analog sources. The internal capacitor-array SAR converter, internal clock, and three-state output interface reduce the number of external support components required for a basic acquisition path. Its 8.5 µs maximum acquisition-and-conversion time supports sampling loops with defined latency, while the 28-pin SOIC package remains accessible for conventional assembly. Designers should isolate analog and digital return paths and place supply-bypass components close to the device to preserve conversion repeatability.
موصى به
Educational and Prototype Converters
ADS774JU is useful in educational instruments and prototype converters because it combines a recognizable parallel ADC interface with an internal reference, clock, and sample-and-hold system. Students or engineers can connect the 12-bit outputs to a microcontroller or programmable logic device and visualize code changes as the analog input varies. The single +5 V supply requirement and 28-pin SOIC package make it suitable for conventional laboratory boards. Before using it as a modern precision reference, account for the finite conversion time, input acquisition requirements, reference behavior, and the legacy nature of the parallel interface.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ ADS774JU — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | ADS7820U | ADS774HIBDW | ADS774HIDW |
|---|---|---|---|---|
| Package | 28-pin SOIC (DW) | 28-pin SOIC | 28-pin SOIC | 28-pin SOIC |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit |
| Sampling Rate | 125 kSPS | 125 kSPS | 117 kSPS | 117 kSPS |
| Input Channels | 1 channel | 1 channel | 1 channel | 1 channel |
| Special Feature | Drop-in replacement for ADC574, ADC674, and ADC774 models in most applications | Reported as a complete replacement with consistent terminals and package | ADS774 family variant with temperature-grade designation HIBD | ADS774 family variant with temperature-grade designation HID |
أبرز الفروقات
- Verified legacy converter replacement (مقابلADC574 and ADC774-class converters)
- Direct same-package 12-bit alternative (مقابلADS7820U)
- Modest conversion-rate difference within drop-in tolerance (مقابلADS774HIBDW and ADS774HIDW)
ملاحظات التصميم
Treat the ADS774JU as a complete replacement for older ADC574-, ADC674-, and ADC774-based circuitry only after checking the original interface. Confirm input polarity and range, output-code format, conversion timing, read/control timing, and pin names against the manufacturer datasheet. The TI datasheet states that replacement is possible in most applications, but board-level compatibility also depends on the external resistor network, logic family, clocking, and system timing surrounding the converter.
Route the analog input directly to the converter and keep the input network compact. Provide a low-impedance source, place any input filter or protection components close to the relevant pins, and avoid routing the analog trace through areas containing switching-node or high-current return paths. Although the ADS774JU includes an internal sample-and-hold circuit, the source must still settle during the acquisition interval. Analog and digital grounds should be joined according to the manufacturer layout guidance, with care taken not to create return current beneath the analog input.
Use a stable supply within the verified 4.5 V to 5.5 V range and place the required bypass capacitor close to the supply pins. Avoid routing converter output-current paths through the analog reference or signal ground. Because the provided excerpts do not expose the ADS774JU current-consumption limit, output-code transition behavior, or complete decoupling values, those details must be taken from the manufacturer datasheet before finalizing the power tree and component selection.
Account for the 12-bit output-bus transition period and the ADC conversion latency when interfacing the three-state outputs to a microprocessor or programmable logic device. Account for bus capacitance, address-decoder timing, and any required settling interval before reading valid data. The device's 8.5 µs maximum acquisition-and-conversion time provides a defined upper conversion interval, but a successful read sequence must also respect the external bus and control timing shown in the datasheet.
معلومات الامتثال
The supplied excerpts identify an industrial-temperature ADC but do not provide explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declarations. No compliance status was inferred from the manufacturer name or package family.