DS1302Z+ - 31B RTC with 3-Wire Serial | Analog Devices
MPN: DS1302Z+ ✓ Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
DS1302Z+ Overview
A real-time clock (RTC) is a timekeeping integrated circuit that maintains calendar information independently of the system clock. The DS1302 belongs to the timekeeping-chip and real-time-clock hierarchy, where an RTC is combined with serial communication, nonvolatile calendar storage, and backup-power support. Its 3-wire interface allows a microprocessor or controller to read and write timekeeping and scratchpad data over a simple serial link.
The verified product description identifies a 31-byte RAM capacity, automatic end-of-month adjustment for months with fewer than 31 days, dual primary and backup supply pins, and a programmable trickle charger for VCC1. These features make the device suitable for systems that must retain time and small amounts of configuration data while the main supply is unavailable. The 8-SOIC package also supports conventional surface-mount PCB assembly.
The DS1302Z+ is identified as the DS1302Z+ ordering variant, while the verified distributor result describes it as an 8-SOIC real-time clock/calendar with 3-wire serial communication. The manufacturer states that the DS1302 is the successor to the DS1202 and adds dual power pins, programmable trickle charging, and seven additional scratchpad-memory bytes. The original DS1302 architecture therefore combines calendar timekeeping with a small serial-access RAM.
Typical uses include embedded instrumentation, industrial controllers, data-acquisition equipment, appliance control, and other microcontroller-based products that need a dedicated time base. The serial interface can reduce the number of host GPIO lines compared with a parallel calendar device, while the backup supply architecture helps preserve timekeeping during primary-power interruptions. Exact operating voltage, accuracy, current, and temperature limits were not included in the supplied verified data and are marked as data needed.
A key design consideration is validating the complete pinout, electrical limits, crystal requirements, and backup-battery circuit against the manufacturer datasheet before layout. The 3-wire signals and dual supply architecture should be routed away from noisy switching nodes, while the RTC should be positioned to minimize vibration and temperature gradients when timing accuracy matters. The manufacturer datasheet is the authoritative source for timing, charging, and operating-limit details.
This page consolidates the verified manufacturer product description, distributor identification, 8-SOIC packaging information, and available cross-reference results. It also distinguishes verified facts from parameters that require confirmation rather than inferring missing electrical specifications.
Drop-in alternatives for DS1302Z+ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
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DS1302Z+T&R
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DS1302Z+T&R
✅ Drop-In📋 Reference alternative (not in catalog)
DS1302Z+
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View Datasheet →DS1302Z+ Specifications
| Product Type | Trickle-charge timekeeping IC |
| Real-Time Clock Function | Real-time clock/calendar |
| Static RAM Capacity | 31 bytes |
| Serial Interface | 3-wire serial |
| Calendar Fields | Seconds, minutes, hours, day, date, month, and year |
| Month-End Adjustment | Automatic adjustment for months with fewer than 31 days |
| Supply Architecture | Dual primary and backup power pins |
| Trickle Charger | Programmable trickle charger for VCC1 |
| Package | 8-SOIC |
| Package Width | 0.154 inch, 3.90 mm |
| Mounting Type | Surface mount |
| Successor Relationship | DS1302 is the successor to the DS1202 |
| Communication Method | Serial communication with a microprocessor |
| RoHS Status | unknown |
| REACH Status | unknown |
| AEC-Q100 Qualification | unknown |
DS1302Z+ 0.154 inch, 3.90 mm Pin Configuration Guide
Pin configuration for DS1302Z+ (0.154 inch, 3.90 mm package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for DS1302Z+.
Refer to the datasheet for full pin configuration.
Typical Applications
DS1302Z+ is suitable for 6 applications: Embedded Data-Acquisition Systems, Industrial Controller Time Stamping, Appliance Control and Monitoring, Portable Instrumentation, Programmable Logic and Test Systems, Battery-Backed Embedded Products.
Embedded Data-Acquisition Systems
DS1302Z+ fits embedded data-acquisition equipment that needs timestamped measurements and a small amount of persistent configuration storage. Its 3-wire serial interface connects the calendar device to a microcontroller without requiring a wide parallel bus, while the 31 bytes of static RAM can hold compact local metadata. The dual primary and backup supply pins help preserve timekeeping when the main supply is interrupted. Verify the exact supply limits, current consumption, and calibration requirements in the official datasheet before implementation.
Recommended
Industrial Controller Time Stamping
The DS1302Z+ is suitable for industrial controllers that record events against calendar fields including seconds, minutes, hours, day, date, month, and year. Automatic adjustment for months with fewer than 31 days reduces software calendar correction, and the 3-wire interface simplifies connection to a controller with limited GPIO. The backup-power arrangement can maintain the time base during brief primary-supply interruptions. Because temperature and accuracy limits were not supplied, use the manufacturer specifications as the release gate.
Recommended
Appliance Control and Monitoring
A real-time clock/calendar like the DS1302Z+ can give appliance controllers a persistent time reference for operating schedules, maintenance logs, and delayed events. The 31-byte static RAM provides limited scratchpad storage for compact operating parameters, while the serial interface reduces the pin burden compared with a parallel calendar. The programmable trickle charger for VCC1 supports backup-power implementation, but the exact charger and battery configuration must be derived from verified electrical data rather than assumed.
Recommended
Portable Instrumentation
DS1302Z+ can support portable instrumentation where measured results must retain calendar context across power cycles or operating sessions. The backup supply architecture is valuable when the instrument is not continuously powered, and the serial interface allows a low-pin-count embedded controller to retrieve and update the time. The 8-SOIC package supports compact surface-mount layouts. Check battery chemistry, backup current, oscillator accuracy, and environmental limits against the official datasheet before selecting the device for a portable product.
Recommended
Programmable Logic and Test Systems
The DS1302Z+ can supply calendar time to programmable-logic or test equipment that needs event ordering across long operating periods. Its 3-wire serial communication is appropriate for controllers that prefer a compact serial peripheral connection, and the 31-byte RAM can hold small system-local values. Automatic month-end handling makes the calendar more useful than a simple counter. Pin timing and electrical levels must be validated from the manufacturer datasheet, especially when the controller operates at a different supply voltage.
Recommended
Battery-Backed Embedded Products
DS1302Z+ is appropriate for embedded products that use a primary supply and a backup source because the manufacturer identifies separate primary and backup power pins. When the primary rail is unavailable, the backup architecture can support continued timekeeping, while the programmable VCC1 trickle charger can recharge an appropriate backup source. The exact backup-cell chemistry, charger limits, and retention behavior are not included in the supplied data, so the battery network must be validated against the official datasheet.
Recommended
Engineering reference data for DS1302Z+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | DS1302Z+T&R | DS1302Z+T&R | DS1302Z+ |
|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC |
| Real-Time Clock/Calendar | Yes | Yes | Yes | Yes |
| Static RAM | 31 bytes | 31 bytes | 31 bytes | 31 bytes |
| Serial Interface | 3-wire serial | 3-wire serial | 3-wire serial | 3-wire serial |
| Backup Power Support | Dual primary and backup power pins | Dual primary and backup power pins | Dual primary and backup power pins | Dual primary and backup power pins |
| Trickle Charger | Programmable charger for VCC1 | Programmable charger for VCC1 | Programmable charger for VCC1 | Programmable charger for VCC1 |
| Calendar Handling | Automatic month-end adjustment | Automatic month-end adjustment | Automatic month-end adjustment | Automatic month-end adjustment |
| Width | 3.90 mm | 3.90 mm | 3.90 mm | 3.90 mm |
Key Differentiators
- Dedicated 3-wire serial RTC/calendar with 31-byte static RAM (vs DS1302Z+T&R)
- Backup-power and trickle-charge integration (vs DS1302Z+T&R)
- Calendar month-end handling (vs DS1302Z+T&R)
Design Notes
Use the DS1302Z+ primary and backup supply pins as separate nets, and confirm the permitted voltage range and backup-current behavior in the manufacturer datasheet before selecting a primary regulator or backup cell. The programmable VCC1 trickle charger is not a substitute for validating the charger-current calculation and battery chemistry. Do not connect an unverified backup source directly to VCC1; verify the intended charge path and polarity first.
Place the DS1302Z+ close to the controller and keep the 3-wire serial traces short and continuous. Route the clock/data/control signals away from high-current switching paths, inductors, and unrelated high-impedance analog nodes. Confirm the exact 8-SOIC pin assignments from the official datasheet because the supplied verified data does not include pin names or numbering. Follow the package land pattern and exposed-pad requirements, if any, from the manufacturer documentation.
Do not substitute an I2C RTC such as a DS1307-class device merely because the calendar functions are similar. DS1302Z+ is documented as a 3-wire serial device with 31 bytes of static RAM and a different power architecture. Firmware drivers, pin assignment, pull-up requirements, and timing must be written for the actual DS1302 interface. Also avoid assuming that the + ordering suffix changes electrical behavior without checking the manufacturer ordering table.
Compliance Information
The supplied verified sources identify the manufacturer, product function, interface, memory, package, and distributor pages but do not provide explicit compliance declarations. Compliance values are therefore unknown rather than assumed.
