Component comparison · Last verified 2026-07-27
Choose DS3231SN# when an industrial-temperature, high-accuracy I2C RTC is needed without user SRAM and the smaller 16-pin wide SOIC is preferred. Choose DS3232SN# when the same industrial temperature range and TCXO accuracy must include 236 bytes of battery-backed SRAM. Their timing and interface capabilities are closely related, but package, pinout and retained-memory requirements prevent a direct PCB substitution.
DS3231SN# vs DS3232SN# specifications
| Specification | DS3231SN# | DS3232SN# |
|---|---|---|
| Battery-backed user SRAM | None | 236 bytes |
| Package / case | 16-pin wide SOIC, 300 mil | 20-pin wide SOIC, 300 mil |
| Operating temperature range | -40 deg C to +85 deg C | -40 deg C to +85 deg C |
| Timekeeping accuracy | +/-2 ppm from 0 deg C to +40 deg C; +/-3.5 ppm from -40 deg C to +85 deg C | +/-2 ppm from 0 deg C to +40 deg C; +/-3.5 ppm from -40 deg C to +85 deg C |
| Serial interface | I2C up to 400 kHz | I2C up to 400 kHz |
| Supply voltage | 2.3 V to 5.5 V | 2.3 V to 5.5 V |
| Timebase | Integrated crystal and TCXO | Integrated crystal and TCXO |
| Time-of-day alarms | Two | Two |
| Digital temperature output | +/-3 deg C accuracy | +/-3 deg C accuracy |
| Reset and clock outputs | RST, INT/SQW and 32 kHz outputs | RST, INT/SQW and 32 kHz outputs |
Key differences
Battery-backed SRAM is the main functional selection point
DS3231SN# has no user SRAM. DS3232SN# adds 236 bytes of battery-backed SRAM for small retained state, calibration values or event data that must survive loss of the main supply.
The additional memory changes the package and footprint
DS3231SN# uses a 16-pin, 300-mil wide SOIC while DS3232SN# uses a 20-pin package of the same width. The body length, land pattern and pin numbering therefore differ even though both use integrated-crystal packages.
A shared RTC core does not make the boards interchangeable
Both industrial codes provide similar TCXO accuracy, alarms, I2C timing, backup operation and temperature output. Selection should be driven by retained-memory need and PCB resources, followed by a full register, pin and qualification review.
Can these parts be interchanged?
DS3231SN# and DS3232SN# are not drop-in replacements. They share an industrial temperature range, high-accuracy integrated TCXO, I2C interface and core RTC features, but DS3232SN# adds 236 bytes of battery-backed SRAM and uses a 20-pin package instead of 16 pins. Verify the footprint, pinout, register map, firmware memory use, backup-current budget and exact orderable code before changing the design.
- Electrical ratings and operating conditions
- Package dimensions, footprint and pinout
- Interface, timing and firmware behavior
- Temperature and qualification grade
- Lifecycle status and current documentation revision
DS3231SN# vs DS3232SN# FAQ
What is the main difference between DS3231SN# and DS3232SN#?
DS3232SN# adds 236 bytes of battery-backed user SRAM. DS3231SN# has no user SRAM and uses a smaller 16-pin package.
Do DS3231SN# and DS3232SN# have the same accuracy and temperature range?
Both industrial codes cover -40 deg C to +85 deg C and specify +/-2 ppm from 0 deg C to +40 deg C and +/-3.5 ppm across the wider industrial range.
Can DS3232SN# directly replace DS3231SN#?
No. DS3232SN# uses a 20-pin wide SOIC while DS3231SN# uses a 16-pin wide SOIC, so the footprint and pinout are different even though many RTC functions are similar.
When is the DS3232SN# SRAM useful?
Its 236 bytes of battery-backed SRAM can retain small application values while main power is absent. Confirm capacity, address map, firmware use and backup-current requirements before relying on it.
Which part is preferable when battery-backed SRAM is not required?
DS3231SN# is usually the simpler choice when the application only needs the industrial-temperature RTC functions and the smaller 16-pin package is advantageous.
Sources and verification
- Analog Devices DS3231 product page
- Analog Devices DS3231 datasheet
- Analog Devices DS3232 product page
- Analog Devices DS3232 datasheet
This comparison supports preliminary selection and sourcing review. Similar specifications do not establish drop-in compatibility. Confirm the complete orderable code and current manufacturer documentation before design release or purchase.
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