NXP Semiconductors PCF85263AUKZ

Overview

PCF85263AUKZ from NXP Semiconductors is a CMOS real-time clock (RTC) and calendar IC with battery switch-over, dual alarms, three timestamp registers, and I²C-bus interface. It operates from 0.9 V to 5.5 V, draws only 0.28 μA at 3.0 V/25 °C, and supports stop-watch mode up to 999 999 hours - used in battery-backed data loggers and network-powered devices.

For engineers reviewing the PCF85263AUKZ datasheet, PCF85263AUKZ pinout, PCF85263AUKZ application, or PCF85263AUKZ equivalent, key selection criteria include its WLCSP12 package footprint, 32.768 kHz crystal calibration support (CL = 6/7/12.5 pF), programmable clock output (1 Hz to 32.768 kHz), and timestamp-triggered event logging on main power loss or external input.

Technical Context

The PCF85263AUKZ implements a BCD-coded RTC with auto-incrementing register addressing (00h–2Fh), dual time modes (RTCM bit selects RTC vs. stop-watch), and independent interrupt generation via INTA (open-drain) and INTB (push-pull). Its oscillator circuit supports configurable load capacitance and includes offset calibration for frequency accuracy.

Three timestamp registers (TSR1–TSR3) capture time-of-event on battery switchover or TS input activation; each timestamp includes full date/time fields in RTC mode or elapsed hours-minutes-seconds in stop-watch mode. Alarm logic enables per-field masking (e.g., alarm on hour only) and outputs to either interrupt pin.

Key Specifications

Pinout & Package

PCF85263AUKZ uses the WLCSP12 (SOT2035-1) package: 1.19 mm × 0.94 mm × 0.22 mm, 0.25 mm pitch, 12 copper pillar terminals. The die pad is electrically isolated; no PCB thermal pad connection required.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar real-time clock applications.

Compared with PCF85263AUKZ, PCF8563T offers lower cost but omits timestamp capture and stop-watch capability, while MCP79412-I/SN adds battery charging at the expense of flexible clock output and dedicated timestamp hardware - making PCF85263AUKZ optimal for event-logging-critical, low-power industrial systems.

Availability

PCF85263AUKZ is available at Aetrix Electronics and suitable for industrial data loggers, smart metering systems, and network-powered IoT gateways requiring stable component supply across extended product lifecycles.

Supply support for PCF85263AUKZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT markets.

The PCF85263AUKZ belongs to NXP's Tiny RTC family, designed specifically for space-constrained, battery-sensitive applications requiring high-accuracy timekeeping, event logging, and seamless power-fail resilience.

FAQ

What is the primary function of the PCF85263AUKZ?

The PCF85263AUKZ is a real-time clock and calendar IC that maintains accurate time and date, supports dual alarms, captures timestamps on power loss or external triggers, and operates in stop-watch mode for elapsed time counting. It delivers these functions with ultra-low power consumption (0.28 μA typical) and integrates a programmable clock output - all in a 1.19 mm × 0.94 mm WLCSP12 package.

How does the PCF85263AUKZ handle power failure?

The PCF85263AUKZ features automatic battery switch-over: when VDD drops below threshold, it seamlessly transitions to VBAT supply without resetting or losing time/date. During switchover, it triggers one of three timestamp registers (TSR1–TSR3) to record the exact time of failure - enabling post-event diagnostics without host processor involvement.

Can the PCF85263AUKZ generate multiple clock frequencies?

Yes, the PCF85263AUKZ provides a programmable clock output with seven selectable frequencies: 1 Hz, 2.048 kHz, 4.096 kHz, 8.192 kHz, 16.384 kHz, and 32.768 kHz. This is configured via the Function register (28h) and eliminates the need for external frequency dividers or separate clock generators in resource-constrained designs.

What crystal specifications are supported by the PCF85263AUKZ?

The PCF85263AUKZ supports 32.768 kHz tuning-fork crystals with configurable load capacitance: 6 pF, 7 pF, or 12.5 pF - selected via bits CL[1:0] in the Oscillator register (25h). This flexibility ensures reliable oscillation across diverse crystal manufacturers and aging characteristics without board-level redesign.

Does the PCF85263AUKZ support both RTC and elapsed time counting modes?

Yes, the PCF85263AUKZ supports two distinct time modes controlled by the RTCM bit in the Function register (28h): RTC mode (calendar with year/month/day) and stop-watch mode (elapsed time from 100th seconds to 999 999 hours). Each mode has dedicated BCD-encoded registers and independent alarm/timestamp functionality.