PCF2127AT/1,518 NXP Semiconductors, PCF2127AT/1,518 Datasheet - Page 27

• Manufacturer Part Number: PCF2127AT/1,518
• Description: IC RTC/CALENDAR TCXO QTZ 20SOIC
• Manufacturer: NXP Semiconductors
• Type: Clock/Calendar/Alarmr

Specifications of PCF2127AT/1,518

• Package / Case: 20-SOIC (0.300", 7.50mm Width)
• Time Format: HH:MM:SS (12/24 hr)
• Memory Size: 512B
• Date Format: YY-MM-DD-dd
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 1.8 V ~ 4.2 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Function: Serial Clock, Timestamp, Timekeeper, Watchdog, Alarm, Calendar, Timer, Timer Interrupt
• Rtc Memory Size: 512 bytes
• Supply Voltage (max): 4.2 V
• Supply Voltage (min): 1.8 V
• Mounting Style: SMD/SMT
• Rtc Bus Interface: I2C
• Supply Current: 2600 nA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

NXP Semiconductors
PCF2127A_2
Product data sheet
The setting of the PORO mode requires that POR_OVRD in register Control_1 is set logic
1 and that the signals at the interface pins SDA/CE and SCL are toggled as illustrated in
Figure
Once the override mode is entered, the device is immediately released from the reset
state and the set-up operation can commence.
The PORO mode is cleared by writing logic 0 to POR_OVRD. POR_OVRD must be
logic 1 before a re-entry into the override mode is possible. Setting POR_OVRD logic 0
during normal operation has no effect except to prevent accidental entry into the PORO
mode.
Fig 15. Power-On Reset (POR) system
Fig 16. Power-On Reset Override (PORO) sequence, valid for both I
reset override
SDA/CE
16. All timings shown are required minimum.
SCL
power up
8 ms
All information provided in this document is subject to legal disclaimers.
SDA/CE
SCL
Rev. 02 — 7 May 2010
OSCILLATOR
POR_OVRD
OVERRIDE
RESET
CLEAR
0 = override inactive
1 = override active
0 = clear override mode
1 = override possible
0 = stopped, 1 = running
minimum 500 ns
osc stopped
Integrated RTC, TCXO and quartz crystal
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reset
PCF2127A
2
C-bus and SPI-bus
minimum 2000 ns
© NXP B.V. 2010. All rights reserved.
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