NXP Semiconductors PCF2120TK/1,118

Overview

PCF2120TK/1,118 from NXP Semiconductors is a CMOS quartz oscillator with integrated 32.768 kHz output, push-pull drive capability, dual on-chip oscillator capacitors, internal power-on reset, and supply voltage range of 1.5 V to 5.5 V. It delivers ultra-low backup current (0.85 µA typical at 3.0 V, 25 °C) and is optimized for battery-powered timing in portable instrumentation and industrial control systems.

For engineers reviewing the PCF2120TK/1,118 datasheet, PCF2120TK/1,118 pinout, PCF2120TK/1,118 application, or PCF2120TK/1,118 equivalent, this device serves as a pre-tuned, crystal-integrated 32 kHz timing source requiring no external load capacitors - critical for space-constrained, low-power real-time clock (RTC) subsystems and energy-sensitive embedded designs.

Technical Context

The PCF2120TK/1,118 integrates a 32.768 kHz quartz oscillator circuit with laser-trimmed frequency accuracy and built-in 6–10 pF integrated load capacitance (CL(itg)), eliminating need for external tuning capacitors. Its oscillator core directly drives a CMOS push-pull CLKOUT stage gated by an active-high CLKOE enable input.

Internal power-on reset ensures deterministic startup behavior, while the TEST pin is internally connected and must remain unconnected in PCB layout. The device operates across −40 °C to +85 °C and supports reliable oscillator start-up when VDD exceeds VDD(min) + 0.3 V.

Key Specifications

Pinout & Package

HVSON10 plastic thermal enhanced very thin small outline package; no leads; 10 terminals; body dimensions 3.0 mm × 3.0 mm × 0.85 mm (SOT650-1).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quartz oscillator applications.

Compared with ABM3B-32.768KHZ-T and SG-210SCB 32.7680KBZ, the PCF2120TK/1,118 uniquely combines integrated capacitors, active enable gating, sub-1 µA backup current, and internal POR - delivering lowest system-level timing BOM count and highest power efficiency in battery-backed RTC designs.

Availability

PCF2120TK/1,118 is available at Aetrix Electronics and suitable for portable instrumentation, industrial sensor nodes, and battery-powered medical devices requiring stable component supply with long-term lifecycle assurance.

Supply support for PCF2120TK/1,118 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 headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and consumer applications.

The PCF2120TK/1,118 belongs to NXP's low-power timing portfolio, designed specifically to replace discrete crystal + inverter circuits in space- and energy-constrained embedded systems requiring robust, pre-calibrated 32 kHz timebases.

FAQ

What is the minimum supply voltage required for reliable startup of the PCF2120TK/1,118?

The PCF2120TK/1,118 requires VDD > VDD(min) + 0.3 V for reliable oscillator start-up at power-up. With a minimum specified supply voltage of 1.5 V, this means VDD must exceed 1.8 V at startup to ensure deterministic oscillation initiation. Below that threshold, the oscillator may fail to start or exhibit extended start-up delay - a condition verified in NXP's static characteristics testing across temperature.

Does the PCF2120TK/1,118 require external load capacitors for the crystal?

No, the PCF2120TK/1,118 does not require external load capacitors. It integrates 6–10 pF of total load capacitance (CL(itg)) internally, optimized for direct connection to standard 32.768 kHz tuning fork crystals. This eliminates two external 12–15 pF capacitors, reducing PCB area, BOM cost, and crystal frequency drift due to parasitic variations - a key feature confirmed in the device's functional description and dynamic characteristics table.

What happens to the CLKOUT pin when CLKOE is driven LOW on the PCF2120TK/1,118?

When CLKOE is driven LOW, the PCF2120TK/1,118 forces CLKOUT to a stable logic LOW level - not high-impedance. This push-pull behavior is explicitly defined in the functional description and pin description table. It ensures predictable downstream logic states during sleep modes, avoiding floating inputs that could cause unintended MCU wakeups or increased leakage in connected peripherals.

Can the PCF2120TK/1,118 operate across the full industrial temperature range?

Yes, the PCF2120TK/1,118 is fully specified and tested from −40 °C to +85 °C. Its 32.768 kHz output maintains ±20 ppm frequency variation over this range, and supply current remains within 265–650 nA (typical) under enabled conditions. These parameters are validated in Tables 5 and 6 of the official NXP datasheet and apply directly to the PCF2120TK/1,118 HVSON10 variant.

Is the TEST pin on the PCF2120TK/1,118 required for normal operation?

No, the TEST pin on the PCF2120TK/1,118 is for factory wafer-level testing only and is internally connected. The datasheet explicitly states "Do not connect pin TEST" and confirms it must remain unconnected in all PCB layouts. Routing or terminating this pin risks compromising oscillator performance or reliability - a requirement documented in Section 13 (Application Information) and Figure 8 (Application Diagram).