PCF2127AT/1,518 NXP Semiconductors, PCF2127AT/1,518 Datasheet - Page 24

• 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
8.6.4.2 Extra power fail detection when the battery switch-over function is disabled
If the battery switch-over function is disabled and the power fail comparator is enabled,
the power fail output at pin PFO depends only on the result of the comparison between
V
Fig 11. PFO signal behavior when battery switch-over is enabled in direct switching
Fig 12. PFO signal behavior when battery switch-over is disabled
PFI
•
•
V
comparator
V
DD
(= 2.5 V)
enabled
V
th(sw)bat
(= 2.5 V)
V
If V
If V
th(sw)bat
V
and 1.25 V:
th(uvp)
(= 0 V)
th(uvp)
V
PF0
V
V
PF0
DD
BAT
PFI
PFI
DD
mode and V
> 1.25 V, PFO = HIGH (through the external pull-up resistor)
< 1.25 V, PFO = LOW
V
All information provided in this document is subject to legal disclaimers.
BBS
th(uvp)
Rev. 02 — 7 May 2010
< V
BAT
internal power supply (= V
comparator always enabled
comparator
disabled
Integrated RTC, TCXO and quartz crystal
BBS
)
PCF2127A
© NXP B.V. 2010. All rights reserved.
t
rec
V
BBS
comparator
001aaj321
enabled
001aaj320
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