|
|
PDF PCF2127A Data sheet ( Hoja de datos )
| Número de pieza | PCF2127A | |
| Descripción | TCXO and quartz crystal | |
| Fabricantes | NXP Semiconductors | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de PCF2127A (archivo pdf) en la parte inferior de esta página. Total 30 Páginas | ||
|
No Preview Available !
PCF2127A
Integrated RTC, TCXO and quartz crystal
Rev. 02 — 7 May 2010
www.DataSheet4U.com
Product data sheet
1. General description
The PCF2127A is a CMOS1 Real Time Clock (RTC) and calendar with an integrated
Temperature Compensated Crystal (Xtal) Oscillator (TCXO) and a 32.768 kHz quartz
crystal optimized for very high accuracy and very low power consumption. The PCF2127A
has 512 bytes of general purpose static RAM, a selectable I2C-bus or SPI-bus, a backup
battery switch-over circuit, a programmable watchdog function, a timestamp function, and
many other features.
2. Features and benefits
Temperature Compensated Crystal Oscillator (TCXO) with integrated capacitors
Typical accuracy: ±3 ppm from −15 °C to +60 °C
Integration of a 32.768 kHz quartz crystal and oscillator in the same package
Provides year, month, day, weekday, hours, minutes, and seconds
512 bytes of general purpose static RAM
Timestamp function
with interrupt capability
detection of two different events on one multilevel input pin (e.g. for tamper
detection)
Two line bidirectional 400 kHz Fast-mode I2C-bus interface (IOL = 3 mA at pin
SDA/CE)
3 line SPI-bus with separate data input and output (maximum speed 6.5 Mbit/s)
Battery backup input pin and switch-over circuitry
Battery backed output voltage pin
Battery low detection function
Extra power fail detection function with input and output pins
Power-On Reset Override (PORO)
Oscillator stop detection function
Interrupt output and system reset pin (open-drain)
Programmable 1 second or 1 minute interrupt
Programmable countdown timer with interrupt capability
Programmable watchdog timer with interrupt and reset capability
Programmable alarm function with interrupt capability
Programmable square wave open-drain output pin
Clock operating voltage: 1.2 V to 4.2 V
Low supply current: typical 0.65 μA at VDD = 3.0 V and Tamb = 25 °C
1. The definition of the abbreviations and acronyms used in this data sheet can be found in Section 17.
1 page  
NXP Semiconductors
www.DataSheet4U.com
PCF2127A
Integrated RTC, TCXO and quartz crystal
8. Functional description
The PCF2127A is a Real Time Clock (RTC) and calendar with an on-chip Temperature
Compensated Crystal (Xtal) Oscillator (TCXO) and a 32.768 kHz quartz crystal integrated
into the same package.
Address and data are transferred by a selectable 400 kHz Fast-mode I2C-bus or a 3 line
SPI-bus with separate data input and output (see Section 9). The maximum speed of the
SPI-bus is 6.5 Mbit/s.
The PCF2127A contains 30 8-bit registers that are used for many different functions, such
as clock, alarm, watchdog, timer, timestamp etc. (see Section 8.1).
The PCF2127A has an output reset pin: the output reset is activated on Power-On Reset
(POR), and whenever the oscillator is stopped (see Section 8.8).
The PCF2127A features 512 bytes of general purpose static RAM, which is battery
backed and can be used independently of the RTC functionality (see Section 8.5).
The PCF2127A has a backup battery input pin and backup battery switch-over circuit
which monitors the main power supply and automatically switches to the backup battery
when a power failure condition is detected (see Section 8.6.1). Accurate timekeeping is
maintained even when the main power supply is interrupted.
A battery low detection circuit monitors the status of the battery (see Section 8.6.3). When
the battery voltage goes below a certain threshold value, a flag is set to indicate that the
battery must be replaced. This can be used to ensure the integrity of the data during
periods of battery backup. A power failure detection circuit monitors the voltage of the
power fail input pin PFI. When the voltage on the power fail input pin PFI goes below an
internal reference (1.25 V), the power fail output pin PFO is activated (see Section 8.6.4).
PCF2127A_2
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 02 — 7 May 2010
© NXP B.V. 2010. All rights reserved.
5 of 80
5 Page 
NXP Semiconductors
www.DataSheet4U.com
PCF2127A
Integrated RTC, TCXO and quartz crystal
8.2.3 Register Control_3
Table 7. Control_3 - control and status register 3 (address 02h) bit description
Bit Symbol
Value Description
Reference
7 to 5 PWRMNG[2:0] [1]
control of the battery switch-over, battery low Section 8.6
detection, and extra power fail detection
functions
4 BTSE
0 [2] no timestamp when battery switch-over Section 8.12.4
occurs
1 time-stamped when battery switch-over
occurs
3 BF
0 [2] no battery switch-over interrupt generated Section 8.6.1
1 flag set when battery switch-over occurs;
flag must be cleared to clear interrupt
2 BLF
0 [2] battery status ok;
Section 8.6.3
no battery low interrupt generated
1 battery status low;
flag cannot be cleared using the interface
1 BIE
0 [2] no interrupt generated from the battery flag Section 8.13.7
(BF)
1 interrupt generated when BF is set
0 BLIE
0 [2] no interrupt generated from battery low flag Section 8.13.8
(BLF)
1 interrupt generated when BLF is set
[1] Values see Table 17.
[2] Default value.
PCF2127A_2
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 02 — 7 May 2010
© NXP B.V. 2010. All rights reserved.
11 of 80
11 Page | ||
| Páginas | Total 30 Páginas | |
| PDF Descargar | [ Datasheet PCF2127A.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| PCF2127A | TCXO and quartz crystal | NXP Semiconductors |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |