NXP Semiconductors PCF1179CT,118

Overview

PCF1179CT,118 from NXP Semiconductors is a single-chip 4.19 MHz automotive LCD clock IC delivering hours, minutes, and seconds with 4-digit duplex LCD drive capability. It integrates an electrically programmable voltage regulator, EEPROM-based time calibration, and 12/24-hour mode selection. Designed for battery-powered car dashboards, it operates across −40 °C to +85 °C with push-button time setting via S1/S2 inputs.

For engineers reviewing the PCF1179CT,118 datasheet, PCF1179CT,118 pinout, PCF1179CT,118 application, or PCF1179CT,118 equivalent, key selection criteria include its 28-lead SO28 package, LCD backplane voltage temperature compensation, 4.19 MHz oscillator accuracy, and EEPROM-programmable calibration without trimming capacitors.

Technical Context

The PCF1179CT,118 implements a 4.194304 MHz crystal oscillator with ±30 ppm tolerance and supports programmable inhibition of 262,144 Hz pulses for time calibration. Its internal logic decodes counters into 1:2 multiplexed segment/backplane outputs driving a 4-digit duplex LCD with three-level backplane signals (VDD, VDD/2, 0).

Time setting uses debounced S1 (hour) and S2 (minute) inputs with auto-increment after 1 s; ENABLE controls their activation. MODE selects 12/24-hour format via VDD/VSS connection, while FLASH toggles colon pulsing at 1 Hz or static display. TS enables test mode with 64× faster debounce timing.

Key Specifications

Pinout & Package

PCF1179CT,118 is housed in a plastic small outline package (SO28) per SOT136-1 standard, with 28 leads and 7.5 mm body width. The package supports standard reflow soldering and meets automotive moisture sensitivity level requirements.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar automotive LCD clock applications.

Compared with PCF1179CT,118, PCF1178CT,118 reduces integration by omitting programmable voltage regulation, while RV-3032-C3 shifts complexity to external drivers but adds calendar support and nanoamp battery current - making PCF1179CT,118 optimal for cost- and space-constrained automotive LCD clocks needing self-contained operation.

Availability

PCF1179CT,118 is available at Aetrix Electronics and suitable for automotive dashboard instrumentation, aftermarket infotainment systems, and commercial vehicle telematics requiring stable component supply, extended temperature operation, and integrated LCD timing.

Supply support for PCF1179CT,118 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 specializing in secure connectivity solutions for automotive, industrial, and IoT applications.

The PCF1179CT,118 belongs to NXP's automotive clock IC product line, engineered specifically for integrated, low-power, temperature-resilient LCD timekeeping in vehicle dashboards and infotainment displays.

FAQ

What is the primary function of the PCF1179CT,118 in automotive systems?

The PCF1179CT,118 serves as a fully integrated automotive LCD clock IC that generates and displays hours, minutes, and seconds on a 4-digit duplex LCD. It incorporates a 4.194304 MHz oscillator, EEPROM-programmable time calibration, temperature-compensated voltage regulation, and direct segment/backplane drive - eliminating the need for external RTC, driver, or trim components in dashboard applications.

How does the PCF1179CT,118 achieve stable LCD contrast across temperature extremes?

The PCF1179CT,118 achieves stable LCD contrast by dynamically adjusting its regulated VDD output based on ambient temperature: e.g., 3–4 V at +85 °C and 5–6 V at −40 °C. This three-level backplane generation (VDD, VDD/2, 0) maintains consistent RMS segment voltages (VON = 0.79VDD, VOFF = 0.35VDD), ensuring readability without manual contrast tuning.

Can the PCF1179CT,118 be used without EEPROM programming during initial deployment?

Yes, the PCF1179CT,118 ships with factory-programmed default values for both time calibration (n = 0 pulses inhibited) and voltage regulator (4.5 V at 25 °C). It operates immediately upon power-up in either 12- or 24-hour mode depending on MODE pin state - EEPROM programming is optional for field calibration or contrast optimization.

What are the key electrical requirements for the crystal oscillator in the PCF1179CT,118?

The PCF1179CT,118 requires a 4.194304 MHz fundamental-mode quartz crystal with ±30 ppm frequency tolerance, 12 pF load capacitance, and series resistance ≤ 50 kΩ. External feedback resistor Rfb must be 300–3000 kΩ, and input/output capacitance is specified at Ci = 16 pF and Co = 27 pF per the datasheet.

Does the PCF1179CT,118 support both 12-hour and 24-hour time formats?

Yes, the PCF1179CT,118 supports both 12-hour and 24-hour formats. The MODE pin selects the mode: connecting MODE to VDD configures 12-hour display (e.g., 1:00 AM), while connecting MODE to VSS selects 24-hour format (e.g., 0:00). An open-circuit MODE pin defaults to 24-hour mode after reset.