DS1338C-33#T&R - 3.3V I2C RTC with 56B NV RAM | ADI
料号： DS1338C-33#T&R ✓ 量产中DS1338C-33#T&R 概述
A real-time clock, or RTC, is a clock-and-timing IC that maintains time independently of the host processor or system clock. Its place in the broader hierarchy is RTC → serial RTC → clock and timing IC → integrated circuit. The DS1338 stores its time and calendar data in binary-coded decimal form, automatically adjusts the end-of-month date for months with fewer than 31 days, and supports leap-year information through its clock/calendar functions.
The principal feature of the DS1338C-33#T&R is the combination of a complete calendar clock and 56 bytes of battery-backed nonvolatile memory in one serial device. The I2C interface transfers both address and data over two wires, reducing the pin and routing burden compared with a parallel RTC. Additional documented functions include a square-wave output, leap-year handling, and automatic month-end adjustment. The specified operating supply range is 3 V to 5.5 V, while the backup battery input accepts 1.3 V to 3.7 V.
The device is designed for low-power timekeeping, with a verified timekeeping current range of 125 µA to 200 µA. Its backup supply allows the clock and calendar, as well as information retained in the nonvolatile memory, to continue operating when the main supply is absent, subject to the device-specific backup implementation. The 16-pin SOIC package supports conventional surface-mount assembly and provides separate access for serial data, timekeeping crystals, supplies, reset, and square-wave functionality, although the supplied source excerpts do not include the complete pin map.
Typical uses include industrial embedded systems, data-logging equipment, metering products, medical instruments, and networked embedded controllers. The 56-byte NV SRAM is useful for small pieces of persistent information such as counters, calibration flags, calibration offsets, event counters, or configuration records. The 3.3 V configuration is particularly appropriate for systems whose logic rails operate at 3.3 V, while the 3 V to 5.5 V main supply range provides flexibility across mixed-voltage equipment.
When designing around this RTC, budget for the exact crystal load capacitance and layout recommended by the manufacturer, and verify startup behavior across the complete temperature range. The I2C pull-up network must tolerate the active bus voltage, while the backup cell or supply path requires careful leakage control to preserve retained data. Because the supplied excerpts do not publish a complete verified pinout, timing accuracy, oscillator trim range, or all lifecycle and environmental limits, engineers should confirm those details in the manufacturer datasheet before release.
This page combines verified manufacturer and distributor information, price and sourcing details as of 2026-10-29, same-package alternative assessment, and application-focused design guidance. It also separates documented facts from unverified parameters so that procurement and engineering decisions can be made without treating unsupported specifications as guaranteed.
直接替换替代料： DS1338C-33#T&R ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： DS1338C-33#T&R （相同外形与封装尺寸） ——差异在于 Package, Serial Interface.
DS1338C-3#
✅ 直接替换联系询价
查看数据手册 →DS1338C-18
✅ 直接替换📋 参考替代料（不在目录中）
DS1339C-33#
✅ 直接替换📋 参考替代料（不在目录中）
DS1340C-33#T&R
✅ 直接替换📋 参考替代料（不在目录中）
DS1338C-33#T&R 规格参数
| Product Type | Serial real-time clock and calendar with 56 bytes of NV SRAM |
| Nominal Supply Voltage | 3.3 V |
| Main Supply Voltage Range | 3 V to 5.5 V |
| Battery Backup Voltage Range | 1.3 V to 3.7 V |
| Timekeeping Current Consumption | 125 µA to 200 µA |
| Serial Interface | I2C, 2-wire |
| Nonvolatile RAM Capacity | 56 bytes |
| Calendar Format | Full binary-coded decimal (BCD) |
| Tracked Time Fields | Seconds, minutes, hours, day, date, month, and year |
| Month-End Adjustment | Automatic for months with fewer than 31 days |
| Leap-Year Support | Yes |
| Square-Wave Output | Yes |
| 封装 | 16-pin SOIC, 0.295-inch body width, 7.50 mm width |
| 安装类型 | Surface mount |
| Ordering Format | Tape and reel |
DS1338C-33#T&R 16-pin soic, 0.295-inch body width, 7.50 mm width 引脚配置指南
DS1338C-33#T&R（16-pin soic, 0.295-inch body width, 7.50 mm width 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： DS1338C-33#T&R.
请参阅 数据手册 以查看完整引脚配置。
典型应用
DS1338C-33#T&R 适用于 6 应用s: Battery-Backed Industrial Data Logger, Smart Utility Metering, Medical Device Time Stamping, Industrial Control and Automation Node, Networked Embedded Equipment, IoT Sensor Node.
Battery-Backed Industrial Data Logger
The DS1338C-33#T&R fits battery-backed industrial data loggers that must preserve timestamps after a power interruption. Its I2C interface connects efficiently to a 3.3 V microcontroller, while the 56-byte NV SRAM can hold counters, a sample index, or a compact calibration offset. The documented 3 V to 5.5 V operating range and 1.3 V to 3.7 V backup range support systems in which the main rail is switched while the backup source remains available. Its 125 µA to 200 µA timekeeping current is a useful baseline, but the complete battery-life calculation must also include pull-ups, the crystal network, and leakage paths.
推荐
Smart Utility Metering
DS1338C-33#T&R is suitable for electricity, water, gas, and environmental meters requiring event timestamps and a limited persistent data area. The 56-byte NV RAM can preserve a limited number of counters, calibration flags, or status bytes without using nonvolatile flash, while the BCD calendar automatically handles month-end date changes. With a 3.3 V system supply and a 125 µA to 200 µA timekeeping-current range, it supports low-duty-cycle metering. Designers should verify the meter's required accuracy, temperature range, oscillator tolerances, and battery backup current directly in the manufacturer documentation before production.
推荐
Medical Device Time Stamping
The DS1338C-33#T&R can provide persistent event timestamps in connected medical and diagnostic equipment where maintaining time through a main-power interruption is important. Its I2C bus reduces connection requirements, and the 56 bytes of NV SRAM are appropriate for small counters or configuration markers rather than bulk patient data. The 3.3 V configuration is suitable for common embedded rails, and the backup input can maintain calendar information when the primary supply is unavailable. Medical designs must additionally verify accuracy, safety requirements, operating temperature, retention behavior, and the applicable product qualification; those details are not supplied in the verified excerpts.
推荐
Industrial Control and Automation Node
DS1338C-33#T&R supports industrial control nodes that need local event time, periodic scheduling, and persistent counters. The square-wave output can serve as a timing reference where the host system needs a predictable cadence, while the RTC maintains calendar information independently of processor downtime. The 3 V to 5.5 V supply range and 3.3 V nominal configuration provide compatibility with embedded industrial controllers, and the two-wire I2C interface simplifies connection to sensors and interface ICs. Factory designs should confirm the full temperature range, startup timing, oscillator tolerance, and backup-source leakage to ensure fit for harsh operating environments.
推荐
Networked Embedded Equipment
DS1338C-33#T&R is useful in routers, gateways, and other networked embedded products that log events or maintain schedules across power cycles. The RTC can timestamp boot events and retain small counters in its 56-byte NV RAM, while I2C provides a compact connection to the main processor. Its 3.3 V configuration aligns with common communications-controller logic rails, and the specified 125 µA to 200 µA timekeeping current supports low-power operation. For equipment exposed to network timing requirements, engineers should compare the RTC accuracy and calibration behavior with the system clock and define which source is authoritative during boot and recovery.
推荐
IoT Sensor Node
The DS1338C-33#T&R fits IoT sensor nodes that must timestamp samples and retain a small amount of state between battery changes or resets. Its I2C interface is well suited to a low-pin-count microcontroller, and the 56-byte NV RAM can hold a sequence number, interval setting, or calibration value. The 3 V to 5.5 V main range and 1.3 V to 3.7 V backup range permit flexible supply arrangements, while the documented 125 µA to 200 µA timekeeping current helps control standby demand. Deployment designs must account for the backup cell's self-discharge, pull-up leakage, radio activity windows, and the RTC's accuracy across its intended temperature range.
推荐
推荐产品汇总
工程参考数据： DS1338C-33#T&R ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | DS1338C-3# | DS1338C-18 | DS1339C-33# | DS1340C-33#T&R |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 16-pin SOIC, 7.50 mm width | 16-pin NSOIC | 16-pin SOIC | 16-pin SOIC | 16-pin SOIC |
| Nominal Supply Voltage | 3.3 V | 3 V | 1.8 V | 3.3 V | 3.3 V |
关键差异点
- Exact 3.3 V family configuration with a broad verified main-supply range （对比 DS1338C-18)
- Documented 56-byte NV SRAM alongside the BCD clock/calendar （对比 DS1339C-33#)
- Complete verified operating and backup supply information （对比 DS1340C-33#T&R)
- Square-wave timing output included in the documented feature set （对比 DS1338C-3#)
设计说明
Place the RTC crystal and its associated load network close to the DS1338C-33#T&R crystal pins, following the manufacturer layout and grounding guidance. Keep high-current switching paths away from the oscillator area to reduce injected noise that can degrade timekeeping. The supplied excerpts do not identify the exact crystal pins, load capacitance, or recommended PCB geometry, so the official DS1338 datasheet and application guidance must control the final layout rather than inferred pin functions.
Validate both the main and backup paths across all normal and fault states. The verified main supply range is 3 V to 5.5 V and the backup range is 1.3 V to 3.7 V. Prevent the backup source from being driven above its allowed range and prevent main-rail leakage from back-feeding the backup domain. Also include I2C pull-up leakage, the crystal circuit, and external load switches in the standby-current budget; the stated 125 µA to 200 µA is timekeeping current, not the complete system consumption.
Design the I2C pull-ups for the active bus voltage and the worst-case total bus capacitance rather than using an arbitrary resistor value. The two-wire interface reduces routing requirements, but a common clock/data ground and short traces remain important for signal integrity. Confirm the device's official I2C address, address pins, operating frequency, and any pull-up requirements from the datasheet because those values are not present in the verified source excerpts.
Do not substitute DS1338C-18 for DS1338C-33#T&R merely because both use a 16-pin package. The family suffixes indicate different nominal voltage configurations, and the -18 option is 1.5 V below the target 3.3 V configuration. Likewise, do not treat DS1338U or DS1338Z package variants as drop-in replacements: the supplied comparisons identify smaller or narrower packages. Always confirm the footprint, pin assignment, voltage, accuracy, and backup behavior before approving a substitution.
合规信息
The verified excerpts mention RoHS details for related comparisons but do not provide an explicit compliance statement for DS1338C-33#T&R. The component is not presented as an automotive-qualified part in the supplied data.
