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Manufacturer Part #


PCF2123 Series 5.5 V Surface Mount SPI Real Time Clock/Calendar - TSSOP-14

Product Specification Section
Technical Attributes
Attributes Table
Date Format: DW:DM:M:Y/Binary
Time Format: HH:MM:SS/Binary
Interface: 3-Wire SPI
Supply Voltage-Nom: 1.1V to 5.5V
Temperature Grade: Industrial
Operating Temp Range: -40°C to +85°C
Storage Temperature Range: -65°C to +150°C
Package Style:  TSSOP-14
Mounting Method: Surface Mount
Features & Applications

The PCF2123 is a CMOS1 Real-Time Clock (RTC) and calendar optimized for low power applications. Data is transferred serially via a Serial Peripheral Interface (SPI-bus) with a maximum data rate of 6.25 Mbit/s. An alarm and timer function is also available providing the possibility to generate a wake-up signal on an interrupt pin. An offset register allows fine tuning of the clock.

Features and benefits:

  • Real time clock provides year, month, day, weekday, hours, minutes, and seconds based on a 32.768 kHz quartz crystal
  • Low backup current while running: typical 100 nA at VDD = 2.0 V and Tamb = 25°C
  • Resolution: seconds to years
  • Watchdog functionality
  • Freely programmable timer and alarm with interrupt capability
  • Clock operating voltage: 1.1 V to 5.5 V
  • 3 line SPI-bus with separate, but combinable data input and output
  • Serial interface at VDD = 1.6 V to 5.5 V
  • 1 second or 1 minute interrupt output
  • Integrated oscillator load capacitors for CL = 7 pF
  • Internal Power-On Reset (POR)
  • Open-drain interrupt and clock output pins
  • Programmable offset register for frequency adjustment


  • Time keeping application
  • Battery powered devices
  • Metering
  • High duration timers
  • Daily alarms
  • Low standby power applications
Pricing Section
Web Price:
$1.22 USD Each
Cost Per Unit

$7.00 reeling fee is amortized over the number of components for each reel.
Mini-Reels are a custom product and are non-cancelable and non-returnable.