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Analog Devices DS1394U-33+T&R — DC-DC Power Modules
Analog Devices

DS1394U-33+T&R Real-Time Clock, SPI, 10-uMAX, Active

MPNDS1394U-33+T&R
End of Life

Maxim Integrated DS1394U-33+T&R, SPI real-time clock/calendar, 10-TFSOP/uMAX, 2.97V to 5.5V supply, 1.3V to 5.5V battery backup, -40°C to 85°C, active.

$4.39Ref. price · indicative, final on quote
DS1394U-33+T&R datasheet
Packaging10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
StockContact for availability
MOQ1 pcs
  • 100% new & originalTraceable channels only — no refurbs, no pulls, no remarked parts.
  • Date & lot codes on quoteStated per line before you commit; label photos on request.
  • MSL-compliant ESD packingMoisture-sealed bags with indicator cards; reels photo-verified.
  • PayPal buyer protectionPay by T/T, PayPal or Payoneer — card payments covered end to end.

Specifications

DS1394U-33+T&R Technical Specifications
ParameterValue
TypeClock/Calendar
Mounting typeSurface Mount
Voltage2.97V ~ 5.5V
Voltage - supply, battery1.3V ~ 5.5V
Current - timekeeping175µA @ 2.97V ~ 5.5V
InterfaceSPI
Operating temperature-40°C ~ 85°C
PackageTape & Reel (TR); Cut Tape (CT)
FeaturesAlarm, Leap Year, Square Wave Output, Trickle-Charger
Date formatYY-MM-DD-dd
Time formatHH:MM:SS:hh (12/24 hr)
Case10-TFSOP, 10-MSOP (0.118\", 3.00mm Width)

Product details

SPI RTC with trickle-charge and alarm — what it does on the board

The Maxim Integrated DS1394U-33+T&R is a SPI-bus real-time clock/calendar in a 10-pin TFSOP/uMAX package. It tracks time in HH:MM:SS:hh (12/24 hr) and date in YY-MM-DD-dd format, with built-in alarm, leap-year compensation, and a square-wave output for system timing references. The integrated trickle-charger keeps a backup supercap or lithium coin cell topped off, so the RTC holds time through a main power loss. The industrial temperature grade (-40°C to 85°C) suits outdoor telecom cabinets, factory-floor controllers, and metering equipment that sees seasonal temperature swings. Surface-mount assembly on a 10-pin MSOP footprint keeps board area tight.

Active production — no LTB risk on this line item

The DS1394U-33+T&R carries an Active product status with ROHS3 compliance. For a production BOM, this part does not carry an obsolescence risk that would trigger a respin or alternate qualification cycle.

Frequently asked questions

What battery voltage does DS1394U-33+T&R support?

The battery-backup input accepts 1.3V to 5.5V, covering standard 3V coin cells (CR2032) and 3.6V lithium primary cells. The low 1.3V floor keeps time on a nearly depleted cell.

Is DS1394U-33+T&R compatible with 3.3V logic?

Yes. The DS1394U-33+T&R operates from a 2.97V to 5.5V supply, so it runs on a 3.3V rail directly. The SPI interface signals are referenced to VCC, so a 3.3V microcontroller can communicate without level translation.

What is the difference between DS1394U and DS1390?

The DS1394U-33+T&R includes a trickle-charger for backup battery or supercap charging, while the DS1390 lacks this feature. Both are SPI RTCs in similar packages, but the trickle-charger on the DS1394U is the deciding factor if the design needs to maintain a backup charge source.