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Analog Devices Inc./Maxim Integrated DS28DG02E-3C+T
- Part No.:
- DS28DG02E-3C+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Memory
- Package:
- 28-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
DS28DG02E-3C+T.pdf
- Description:
- IC EEPROM 2KBIT SPI 2MHZ 28TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,952
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Product details
Overview
DS28DG02E-3C+T from Maxim Integrated is a 2Kb SPI EEPROM with integrated 12-channel PIO, real-time clock/calendar with alarm, CPU reset monitor, battery monitor, and watchdog timer. It operates from 2.2V to 5.25V over –40°C to +85°C, supports up to 2MHz SPI (modes 0,0 and 1,1), and features factory-set 3.3V ±5% VCC trip point for power-fail reset - used in asset-tracking systems and patient-monitoring devices requiring nonvolatile configuration and time-stamped event logging.
For engineers reviewing the DS28DG02E-3C+T datasheet, DS28DG02E-3C+T pinout, DS28DG02E-3C+T application, or DS28DG02E-3C+T equivalent, this page delivers verified technical context, exact pin functions for TSSOP-EP package, confirmed EEPROM endurance (200k cycles), RTC leap-year compensation, and two validated alternative parts with documented functional trade-offs.
Technical Context
The DS28DG02E-3C+T integrates memory, timing, monitoring, and I/O control into a single SPI-accessible device: its 256 × 8 EEPROM is partitioned into four 64-byte blocks with programmable write protection per block; the RTC uses BCD format, 32.768kHz crystal input, and automatically adjusts for leap years through year 2099.
Its 12 PIOs support configurable direction (input/output), output type (push-pull/open-drain), and current mode (low/high), with power-on defaults stored in NV memory; the VCC monitor provides hysteresis (0.4–0.6% of VTRIP) and debounced manual reset via RSTZ, while battery monitor thresholds (2.5V/2.25V/2.0V/1.75V) and watchdog timeouts (1.6s/0.8s/0.4s/0.2s) are user-programmable via NV registers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| EEPROM capacity | 2Kb (256 × 8), organized as four 64-byte blocks with individual block write-protection |
| SPI interface | Supports modes (0,0) and (1,1) at up to 2MHz - enables interoperability with standard microcontroller SPI peripherals |
| RTC accuracy | ±46ppm frequency deviation with 32.768kHz crystal (12.5pF, ESR ≤ 45kΩ) - ensures calendar correctness across temperature |
| VCC monitor trip point | 3.3V −5% (2.97V min, 3.14V max at +25°C) with 0.4–0.6% hysteresis - prevents false resets during supply transients |
| Battery monitor thresholds | User-selectable: 2.5V, 2.25V, 2.0V, or 1.75V - allows flexible backup power management for RTC/RSTZ retention |
| Watchdog timeout | Programmable: 1.6s / 0.8s / 0.4s / 0.2s (typ) - supports diverse system recovery timing requirements |
| Operating range | −40°C to +85°C, 2.2V to 5.25V - qualified for industrial and medical-grade embedded applications |
Pinout & Package
DS28DG02E-3C+T is housed in a 28-lead, 4.4mm TSSOP-EP package with exposed paddle soldered to PCB ground plane for thermal and electrical stability.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| X1 | 32.768kHz crystal input (pin 1) | Connects to one terminal of external tuning fork crystal or TCXO output - essential for RTC timebase |
| X2 | 32.768kHz crystal return (pin 2) | Completes crystal oscillator loop; requires no external load capacitors when using specified 12.5pF crystal |
| RSTZ | Open-drain reset output / manual reset input (pin 3) | Active-low reset signal with debounce; sinks current from VBAT when VCC fails - ensures clean CPU reset |
| WDI | Watchdog input (pin 4) | Active-high strobe to clear watchdog timer; must be toggled within timeout window to prevent WDOZ assertion |
| WDOZ | Open-drain watchdog alarm output (pin 5) | Asserts low on timeout - can drive external interrupt or latch circuit without pull-up dependency |
| WPZ | Hardware write-protect enable (pin 6) | Active-low pin that locks EEPROM blocks and NV registers when asserted - provides physical security layer |
| PIO0–PIO11 | Configurable bidirectional I/O (pins 7–9, 11–13, 16–18, 20–22) | 12 independent lines supporting LED drive, sensor interfacing, or control signaling; each retains power-on state in NV memory |
| ALMZ | Open-drain alarm output (pin 23) | Combines RTC alarm, battery alarm, and watchdog alarm into single active-low signal - reduces GPIO count |
| SO/SI/SCK/CSZ | SPI data out/in, clock, chip select (pins 24–27) | Standard 4-wire SPI interface - compatible with MCU SPI peripherals without protocol translation |
| VBAT | Backup battery supply (pin 28) | Powers RTC and RSTZ during main supply loss - enables continuous timekeeping and fail-safe reset generation |
Key Features
| Feature | Design Value |
|---|---|
| Unique 64-bit registration number | Factory-programmed ROM ID (address 118h–11Fh) enables device-level traceability and secure identification in distributed systems |
| EEPROM endurance & retention | 200k write cycles per page at +25°C; 40-year data retention at +85°C - suitable for long-life field-deployed equipment |
| PIO flexibility | Each of 12 PIOs independently configurable as input/output, push-pull/open-drain, with programmable read inversion - simplifies mixed-signal peripheral interfacing |
| RTC/calendar with leap-year logic | BCD-encoded time/date registers auto-correct for leap years through 2099 - eliminates firmware calendar maintenance overhead |
| Triple alarm outputs | RSTZ (power-fail), WDOZ (watchdog), ALMZ (combined RTC/battery/watchdog) - enables layered fault response without external logic |
| ESD robustness | ±4kV IEC 1000-4-2 protection on all pins except X1/X2 - enhances reliability in handling-sensitive industrial environments |
Applications
| Asset-Tracking Systems | Patient-Monitoring Systems |
|---|---|
Use Scenario: Tamper-evident GPS loggers deployed on shipping containers record location, temperature, and door-open events with precise timestamps. IC Role / Device Role / Timing Role: DS28DG02E-3C+T provides nonvolatile event storage, real-time timestamping, and battery-backed RTC to maintain time during power interruptions. Use Value: Eliminates need for separate RTC, EEPROM, and reset IC - reduces BOM count and PCB area while ensuring time continuity across supply gaps. |
Use Scenario: Portable ECG monitors log heart rate, arrhythmia markers, and patient identifiers during multi-day Holter studies. IC Role / Device Role / Timing Role: DS28DG02E-3C+T stores calibration data, records time-stamped waveform metadata, and triggers alarms on battery depletion or communication failure. Use Value: Single-chip integration of battery monitor, RTC alarm, and EEPROM enables compact, low-power design compliant with IEC 60601-1 leakage limits. |
| Home Lighting Control Systems | Broadband Access Network Equipment |
Use Scenario: Smart wall switches store user-configured dimming profiles, scene schedules, and firmware update status across power cycles. IC Role / Device Role / Timing Role: DS28DG02E-3C+T acts as configuration manager and time scheduler - its RTC drives daily lighting automation sequences. Use Value: Programmable RTC alarm wakes host MCU only when needed (e.g., sunrise/sunset), cutting system standby current by >50% versus polling-based timers. |
Use Scenario: DSLAM line cards monitor voltage rails, detect fan failures, and log uptime statistics across 24/7 operation. IC Role / Device Role / Timing Role: DS28DG02E-3C+T serves as system health supervisor - its watchdog resets hung processors, while VCC/battery monitors flag power anomalies. Use Value: Factory-trimmed VCC trip point (2.97–3.14V) and hysteresis ensure stable reset behavior under noisy telecom power conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar multifunction supervisory IC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6361KA31+T | Dedicated 3.08V reset IC with watchdog and manual reset; no EEPROM, RTC, or PIO | Lacks timekeeping, nonvolatile storage, and I/O expansion - suitable only for basic reset supervision | Select when only power-monitoring and reset functionality is required; lower cost but no system integration benefit |
| DS1339U-33+T | Standalone I²C RTC with 56-byte RAM and trickle-charge controller; no EEPROM, PIO, or voltage monitoring | Provides higher-accuracy RTC (±2ppm) but requires external EEPROM and reset IC for full DS28DG02E-3C+T functionality | Choose for precision timing-critical applications where external component count is acceptable and EEPROM/monitoring are handled separately |
Compared with MAX6361KA31+T and DS1339U-33+T, DS28DG02E-3C+T uniquely consolidates EEPROM, RTC, 12-channel PIO, dual voltage monitors, and watchdog into one SPI device - reducing interconnect complexity, board space, and qualification effort for new designs requiring coordinated time, storage, and supervision.
Availability
DS28DG02E-3C+T is available at Aetrix Electronics and suitable for asset-tracking systems, patient-monitoring devices, and broadband network equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for DS28DG02E-3C+T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Maxim Integrated (now part of Analog Devices) designs high-performance analog and mixed-signal ICs for industrial, medical, and communications applications - emphasizing integration, reliability, and precision.
DS28DG02E-3C+T belongs to Maxim's multifunction supervisory IC product line, engineered to replace discrete reset, RTC, EEPROM, and I/O components in space-constrained embedded systems demanding time-aware fault recovery and nonvolatile configuration.
FAQ
What is the factory-set VCC trip point for DS28DG02E-3C+T?
The DS28DG02E-3C+T has a factory-set VCC monitor trip point of 3.3V −5%, meaning 2.97V minimum and 3.14V maximum at +25°C. This threshold is fixed and cannot be reprogrammed. The device includes hysteresis (0.4–0.6% of VTRIP) to prevent chatter during marginal supply conditions. DS28DG02E-3C+T uses this trip point to assert the RSTZ output when VCC falls below the limit, ensuring reliable CPU reset during brownout events.
Does DS28DG02E-3C+T support both SPI modes 0,0 and 1,1?
Yes, DS28DG02E-3C+T natively supports SPI modes (0,0) and (1,1) without configuration - it automatically detects and adapts to the host's clock polarity and phase settings. This eliminates the need for mode-specific initialization code and ensures compatibility with common microcontrollers like STM32, PIC, and NXP Kinetis families. DS28DG02E-3C+T operates at up to 2MHz clock frequency in either mode, with guaranteed timing margins per the datasheet's SPI interface table.
How is the RTC powered during main supply loss?
DS28DG02E-3C+T maintains RTC operation during VCC loss by switching to VBAT supply - the RTC and RSTZ circuitry remain fully functional as long as VBAT ≥ 1.5V. When VCC drops below VPOR (2.13V), the device transitions to battery backup mode, preserving time, calendar, and alarm registers. DS28DG02E-3C+T draws only 4.7µA typical from VBAT at +25°C with RTC running, enabling multi-year operation on small coin cells.
Can all 12 PIOs on DS28DG02E-3C+T be configured as open-drain outputs?
Yes, DS28DG02E-3C+T allows grouping-based output type selection: PIO0–PIO3, PIO4–PIO7, and PIO8–PIO11 each share a common output type setting (push-pull or open-drain) controlled by bits OT1, OT2, and OT3 in register 10Fh/125h. All 12 PIOs can therefore be set to open-drain simultaneously. DS28DG02E-3C+T also supports LED drive capability per PIO, with sink current up to 30mA at VCC = 5.25V (subject to total 270mA package limit).
What is the endurance rating for DS28DG02E-3C+T EEPROM writes?
DS28DG02E-3C+T guarantees 200,000 write cycles per 16-byte EEPROM page at +25°C, with a maximum write cycle time of 10ms. Endurance is specified per page, not per byte, and applies to all four 64-byte blocks. The device supports single-byte and up to 16-byte page writes via SPI, and write-protection can be enabled per block (1, 2, or all 4 blocks) using the WPZ pin or software commands. DS28DG02E-3C+T retains data for 40 years at +85°C, making it suitable for long-lifecycle industrial deployments.
DS28DG02E-3C+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 28-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 2Kbit
- Memory Organization:
- 256 x 8
- Memory Interface:
- SPI
- Clock Frequency:
- 2 MHz
- Write Cycle Time - Word, Page:
- -
- Access Time:
- -
- Voltage - Supply:
- 2.2V ~ 5.25V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-TSSOP-EP
DS28DG02E-3C+T FAQ
1.How can I place an order for DS28DG02E-3C+T through Aetrix?
Please submit a Request for Quotation (RFQ) for DS28DG02E-3C+T on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for DS28DG02E-3C+T reliable?
The price and inventory of DS28DG02E-3C+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DS28DG02E-3C+T is usually 5 days.
3.What payment methods are accepted for DS28DG02E-3C+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DS28DG02E-3C+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DS28DG02E-3C+T?
DS28DG02E-3C+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DS28DG02E-3C+T order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for DS28DG02E-3C+T?
For technical support, including DS28DG02E-3C+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DS28DG02E-3C+T requirements.
6.How does Aetrix verify that DS28DG02E-3C+T is sourced from the original manufacturer or authorized distributors?
All DS28DG02E-3C+T products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that DS28DG02E-3C+T meets industry standards.
7.What is the process for return or replacement of DS28DG02E-3C+T?
All DS28DG02E-3C+T units undergo pre-shipment inspection (PSI). If there is an issue with DS28DG02E-3C+T, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The DS28DG02E-3C+T part is unused and in its original packaging.
Return procedure for DS28DG02E-3C+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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