PCF85263ATLSLASHAX datasheet(54/102 Pages) NXP

54 / 102 page

NXP Semiconductors

PCF85263A

Tiny RTC/Calendar with Alarm Function, Battery Switch-Over, Time Stamp Input, and I2C-bus

STOP bit [1]

TSL

TS pin [2]

Oscillator state

Description

Stopped

Running

TS pin active LOW

Stopped

TS pin ignored

Table 56. Oscillator stop control when STOPM = 1...continued

[1]

Refer to the Oscillator register (Section 7.10).

[2]

TSPM[1:0] = 11.

7.13.5 COF[2:0]: Clock output frequency

Frequency selection (Hz)

Bit

Symbol

Value

CLK pin

TS pin

INTA pin

000 [1]

32 768

001

16 384

010

8 192

011

4 096

100

2 048

101

1 024

110

2 to 0

COF[2:0]

111

Static LOW

Hi-Z

Table 57. COF[2:0] bits - Function control register (address 28h)

[1]

Default value.

A programmable square wave is available at pin CLK. Operation is controlled by the COF[2:0] bits. Frequencies

of 32.768 kHz (default) down to 1 Hz can be generated for use as a system clock, microcontroller clock, input to

a charge pump, or for calibration of the oscillator.

Pin CLK is a push-pull output and enabled at power on. Pin CLK can be disabled by setting CLKPM = 1 in the

Pin_IO register (Section 7.12). When disabled, the CLK pin is LOW.

The selected clock frequency may also be output on the TS pin and the INTA pin. The CLKIV bit may be used to

invert the clock output. CLKIV does not invert for the setting COF[2:0] = 111.

The duty cycle of the selected clock is not controlled. However, due to the nature of the clock generation, all

clock frequencies except 32.768 kHz have a duty cycle of 50:50.

COF[2:0]

Frequency (Hz)

Typical duty cycle [1]

000 [2]

32 768

60 : 40 to 40 : 60

001

16 384

50 : 50

010

8 192

50 : 50

011

4 096

50 : 50

100

2 048

50 : 50

101

1 024

50 : 50

110

1 [3]

50 : 50

Table 58. Clock duty cycles

PCF85263A

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 5.4 — 12 December 2025

Document feedback

54 / 102

PCF85263ATL/AX Datasheet(PDF) 54 Page - NXP Semiconductors

PCF85263ATL/AX Datasheet(HTML) 54 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL