DS1338U-18+T&R - 56-Byte I2C RTC | Analog Devices
MPN: DS1338U-18+T&R ✓ نشطDS1338U-18+T&R نظرة عامة
A real-time clock is a clock-and-timing IC that continues tracking calendar time independently of a host processor. Within the semiconductor hierarchy, it belongs to the clock and timing family, while its serial interface and nonvolatile storage place it within the broader category of real-time clock and calendar devices. Unlike a basic digital counter, this RTC records date information and automatically adjusts the end-of-month date for months containing fewer than 31 days.
The DS1338U combines an RTC calendar function with 56 bytes of NV SRAM in one package. That SRAM provides persistent space for configuration data, counters, fault flags, or other small records that an embedded controller can access through the same two-wire bus. The integrated arrangement reduces the component count and board area required for a system that needs both timekeeping and a small nonvolatile data store.
Communication occurs through an I2C serial interface using two wires for address and data transfer. This interface is suitable for embedded controllers that need to read the current time, configure clock registers, or access the NV SRAM without dedicating multiple parallel pins. The device is identified in the supplied distributor records as an industrial-temperature-grade component in an 8-terminal gull-wing package.
Typical uses include industrial embedded controllers, data-acquisition equipment, connected instrumentation, access-control terminals, utility metering, and compact consumer appliances. In each case, the RTC supplies calendar data while the NV SRAM can retain operating state between resets. The two-wire interface also helps preserve connector pins and PCB routing resources in space-constrained designs.
Designers should treat the backup supply, oscillator accuracy, operating voltage, and electrical limits as parameters that require confirmation from the manufacturer datasheet. The supplied verified records do not provide those numeric values, so this page does not infer them. PCB planning should also verify the exact uSOP footprint and pin assignment before release, because the distributor listing refers to an 8-pin uSOP form rather than reproducing the complete pinout.
This page consolidates verified distributor identification, the official Analog Devices product description, cross-reference findings, practical integration guidance, and a structured comparison of supported same-family alternatives. It is intended to accelerate component identification while clearly separating confirmed information from values that still require datasheet verification.
بدائل مباشرة لـ DS1338U-18+T&R — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
الطرازات في هذه السلسلة
طرازات من نفس السلسلة متوافقة تمامًا مع DS1338U-18+T&R (نفس عامل الشكل والبصمة) — يختلف في Product Type, Serial Interface, Package, Package Type, RoHS Status.
DS1338U-33+T&R
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
DS1340U-33+T&R
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
DS1338U-10+T&R
✅ بديل مباشر ⚠️ مواصفات غير مُتحقق منها📋 بديل مرجعي (غير موجود في الكتالوج)
DS1338U-12+T&R
✅ بديل مباشر ⚠️ مواصفات غير مُتحقق منها📋 بديل مرجعي (غير موجود في الكتالوج)
DS1338U-20+T&R
✅ بديل مباشر ⚠️ مواصفات غير مُتحقق منها📋 بديل مرجعي (غير موجود في الكتالوج)
DS1338U-18+T&R المواصفات
| Product Type | Serial real-time clock and calendar |
| Nonvolatile SRAM Capacity | 56 byte |
| Serial Interface | I2C |
| Interface Conductor Count | 2 wire |
| Package Type | 8-pin uSOP |
| Package Width | 3.00 mm |
| Terminal Count | 8 |
| Temperature Grade | Industrial |
| Time Format | HH:MM:SS in 12-hour or 24-hour format |
| Date Format | YY-MM-DD-dd |
| Calendar Representation | Full binary-coded decimal |
| Month-End Adjustment | Automatic for months with fewer than 31 days |
| حالة RoHS | Compliant for the compared DS1338U-33+T&R variant |
دليل تكوين أطراف DS1338U-18+T&R 3.00 mm
تكوين الأطراف لـ DS1338U-18+T&R (حزمة 3.00 mm). يتم تعريف ترقيم الأطراف والوظائف ومخططات التوصيل في ورقة البيانات الفنية من الشركة المصنعة. راجعها للحصول على البصمة الدقيقة وإرشادات اللحام.
لا تتوفر بيانات مفصلة لمخطط التوصيلات لـ DS1338U-18+T&R.
راجع ورقة البيانات للحصول على تكوين الأطراف الكامل.
التطبيقات النموذجية
DS1338U-18+T&R مناسب لـ 6 التطبيقs: Industrial Data-Acquisition Equipment, Connected Utility Meters, Access-Control and Security Terminals, Network-Connected Sensor Hubs, Medical Monitoring Systems, Compact Consumer Appliances.
Industrial Data-Acquisition Equipment
The DS1338U-18+T&R is suitable for industrial data-acquisition equipment that must timestamp samples and retain limited operating information between controller resets. Its full binary-coded decimal clock/calendar tracks seconds, minutes, hours, day, date, month, and year through a two-wire I2C interface. The integrated 56-byte NV SRAM can hold configuration flags, batch counters, or calibration records without requiring a separate EEPROM. Because the controller and RTC share the same serial bus, the design preserves connector pins and simplifies routing. The verified excerpts confirm industrial temperature grade, 8-pin uSOP construction, 12-hour or 24-hour formats, and automatic month-end adjustment. Supply voltage, oscillator accuracy, and backup-supply details must still be confirmed from the manufacturer datasheet before specifying timing accuracy.
موصى به
Connected Utility Meters
The DS1338U-18+T&R fits connected utility meters where a host processor needs calendar-level timekeeping and persistent small records alongside communication electronics. The 56-byte NV SRAM can retain an interval counter, service flag, or configuration checksum across resets, while the RTC maintains a full date and time independently of the main controller's execution cycle. A two-wire I2C connection allows the controller to read or update the clock through the same bus used for other low-speed peripherals. Its 8-pin uSOP format supports compact meter-board layouts. The automatic end-of-month adjustment is useful for daily event logs, and the supported 12-hour and 24-hour formats accommodate different regional requirements. Meter designers should verify backup-battery behavior, supply limits, and oscillator accuracy before using the timestamps for legally relevant records.
موصى به
Access-Control and Security Terminals
The DS1338U-18+T&R can support access-control terminals that record event times and retain a small number of operational flags between controller restarts. Calendar registers provide seconds through year information, while the 56-byte NV SRAM can preserve counters, terminal identifiers, or status bits without occupying a separate serial EEPROM. The two-wire I2C interface reduces connection requirements to the controller and is convenient in terminals where keypad, display, network, and communications interfaces already share a control board. The industrial-grade classification and 8-pin uSOP package make the part suitable for compact control electronics, provided the specified temperature range meets the installation environment. Before deployment, verify the backup source, current consumption, oscillator tolerance, and complete uSOP pinout in the manufacturer documentation, because those details were not included in the supplied search excerpts.
موصى به
Network-Connected Sensor Hubs
The DS1338U-18+T&R is useful in network-connected sensor hubs that add timestamp context to measurements collected by an embedded host. The RTC maintains a complete BCD calendar, allowing the controller to associate sensor events with a date and time rather than relying only on an external network time source. The 56 bytes of NV SRAM can retain a synchronization flag, sample counter, or last-known configuration. Because the device uses a two-wire I2C connection, it can share a controller bus with other low-speed devices and avoids a separate parallel timekeeping interface. Its small 8-pin uSOP package supports compact sensor assemblies. For gateways operating through long standby periods, the engineer must verify backup-supply endurance, oscillator accuracy across temperature, and supply-voltage tolerances from the manufacturer datasheet before defining the timestamp quality of the system.
موصى به
Medical Monitoring Systems
The DS1338U-18+T&R can support medical monitoring equipment that timestamps measurements and preserves limited configuration information between control-system restarts. The full calendar tracks seconds through year, enabling records to include a useful date and time rather than only elapsed time, while 56 bytes of NV SRAM can hold patient-record counters, device flags, or setup values. The two-wire I2C interface minimizes host-controller pin usage, and the 8-pin uSOP package supports compact instrument electronics. Because this application may demand controlled timing accuracy and reliable data retention, the designer must confirm oscillator tolerance, backup-battery behavior, current consumption, and operating-temperature limits directly from the Analog Devices documentation. The verified product information confirms the calendar, NV RAM, I2C interface, and package, but it does not provide medical certification or clinical-timing claims.
موصى به
Compact Consumer Appliances
The DS1338U-18+T&R fits compact appliances that need a persistent event time and a small amount of nonvolatile operating data. For example, a controller can use the RTC for delayed start, service intervals, or timer history while storing 56 bytes of flags or counters in the integrated NV SRAM. The I2C interface limits host wiring, and the 8-pin uSOP package leaves board area available for the appliance's main power, communications, and user-interface circuitry. Both 12-hour and 24-hour formats are supported, and the calendar automatically accounts for months shorter than 31 days. Before finalizing the design, verify the exact uSOP footprint, pin functions, supply-voltage range, oscillator accuracy, and backup requirements in the manufacturer datasheet. These unresolved electrical details are essential when the appliance must preserve time during brief power interruptions.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ DS1338U-18+T&R — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | DS1338U-33+T&R | DS1340U-33+T&R | DS1338U-10+T&R | DS1338U-12+T&R | DS1338U-20+T&R |
|---|---|---|---|---|---|---|
| Package | 8-pin uSOP | 8-pin uSOP - same | 8-pin uSOP - same | 8-pin uSOP - same | 8-pin uSOP - same | 8-pin uSOP - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Product Type | I2C RTC with calendar and NV RAM | I2C RTC with 56-byte NV RAM | I2C real-time clock | DS1338U-family serial RTC | DS1338U-family serial RTC | DS1338U-family serial RTC |
| Serial Interface | 2-wire I2C | 2-wire I2C | I2C | I2C | I2C | I2C |
| Temperature Grade or Suffix | Industrial grade, -18 suffix | -33 suffix | -33 suffix | -10 suffix | -12 suffix | -20 suffix |
أبرز الفروقات
- Integrated calendar clock and persistent storage (مقابلDS1340U-33+T&R)
- Verified industrial-grade -18 ordering option (مقابلDS1338U-33+T&R)
- Two-wire host-controller interface (مقابلDS1338U-10+T&R)
- Matched calendar formats across the principal same-family candidate (مقابلDS1338U-33+T&R)
ملاحظات التصميم
Confirm the exact uSOP-8 land pattern and pin names against the Analog Devices manufacturer datasheet before releasing the PCB. The verified distributor descriptions consistently identify an eight-pin uSOP form but do not expose the individual pin assignments. Place the RTC close to the host controller and its I2C routing, keep the oscillator path away from high-current switching traces, and follow the manufacturer's recommended grounding and component-placement pattern.
Define the backup-supply strategy before schematic release because persistent calendar and NV SRAM operation may depend on continued auxiliary power. The verified excerpts do not state supply voltage, operating current, or backup-battery requirements. These values must come from the manufacturer datasheet and must be checked against battery capacity, load-switch leakage, and the maximum duration of a power interruption. Do not select a backup component from generic assumptions.
Keep the RTC and its oscillator components away from noisy regulators, relay drivers, high-current switching nodes, and long high-speed digital routes. Follow the manufacturer's recommended crystal load-capacitance calculation and grounding arrangement. The I2C lines should be routed as a short two-wire bus, with pull-ups selected only after confirming the bus voltage, capacitance, and maximum bus speed from the applicable device documentation.
Do not treat DS1338U temperature-suffix changes as automatically interchangeable. The supplied data confirms the same uSOP footprint and RTC/NV RAM concept for the listed family candidates, but it does not provide complete operating-temperature, voltage, accuracy, or pin-function tables. Before substitution, compare every electrical limit, verify the PCB land pattern, and check that the backup supply and time accuracy remain acceptable for the end application.
معلومات الامتثال
The supplied Xecor comparison states RoHS details for DS1338U-33+T&R. No verified REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals statement was provided for DS1338U-18+T&R, so those fields remain unknown.
