PCF2127 View Datasheet(PDF) - NXP Semiconductors.
Part Name
Description
MFG CO.
'PCF2127' PDF : 101 Pages View PDF
NXP Semiconductors
PCF2127
Accurate RTC with integrated quartz crystal for industrial applications
Three power management functions are implemented:
Battery switch-over function. monitoring the main power supply VDD and switching to
VBAT in case a power fail condition is detected (see Section 8.6.1).
Battery low detection function. monitoring the status of the battery, VBAT (see
Section 8.6.2).
Extra power fail detection function. monitoring the voltage at the power fail input pin,
PFI (see Section 8.6.3).
The power management functions are controlled by the control bits PWRMNG[2:0] (see
Table 25) in register Control_3 (see Table 11):
Table 25. Power management control bit description
PWRMNG[2:0]
Function
000
[1] battery switch-over function is enabled in standard mode;
battery low detection function is enabled;
extra power fail detection function is enabled
001
battery switch-over function is enabled in standard mode;
battery low detection function is disabled;
extra power fail detection function is enabled
010
battery switch-over function is enabled in standard mode;
battery low detection function is disabled;
extra power fail detection function is disabled
011
battery switch-over function is enabled in direct switching mode;
battery low detection function is enabled;
extra power fail detection function is enabled
100
battery switch-over function is enabled in direct switching mode;
battery low detection function is disabled;
extra power fail detection function is enabled
101
battery switch-over function is enabled in direct switching mode;
battery low detection function is disabled;
extra power fail detection function is disabled
110
[2] battery switch-over function is disabled - only one power supply
(VDD);
battery low detection function is disabled;
extra power fail detection function is enabled
111
[2] battery switch-over function is disabled - only one power supply
(VDD);
battery low detection function is disabled;
extra power fail detection function is disabled
[1] Default value.
[2] When the battery switch-over function is disabled, the PCF2127 works only with the power supply VDD.
VBAT must be put to ground and the battery low detection function is disabled.
PCF2127
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 8 — 19 December 2014
© NXP Semiconductors N.V. 2014. All rights reserved.
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