Diodes Incorporated PT7C4363BQ1WEX

Overview

PT7C4363BQ1WEX from Diodes Incorporated is an AEC-Q100 qualified automotive real-time clock (RTC) IC with I²C interface, 24-hour BCD time/calendar counter, programmable square-wave output (1 Hz / 32 Hz / 1.024 kHz / 32.768 kHz), alarm/timer interrupt capability, and oscillator fail detection. It operates from 1.3 V to 5.5 V across –40°C to +125°C and draws only 400 nA typical backup current at 3.0 V.

For engineers reviewing the PT7C4363BQ1WEX datasheet, PT7C4363BQ1WEX pinout, PT7C4363BQ1WEX application, or PT7C4363BQ1WEX equivalent, this device supports high-ESR crystals up to 100 kΩ, integrates automatic leap-year correction, provides open-drain INT/SQW outputs, and delivers precise timing for infotainment, ADAS domain controllers, and body electronics requiring PPAP-capable, IATF 16949-manufactured components.

Technical Context

The PT7C4363BQ1WEX implements a fully autonomous RTC core with BCD-encoded time and calendar registers (seconds through years), including century-bit handling and auto-adjustment for variable month lengths and leap years up to year 2100. Its oscillator circuit supports external 32.768 kHz crystals with built-in 5 pF/20 pF load capacitance and optional external tuning capacitors.

It features dual interrupt sources - alarm (configurable on second/minute/hour/date/day) and timer (with four selectable source clocks: 4.096 kHz, 64 Hz, 1 Hz, or 1/60 Hz) - both routed to the open-drain INT pin. The SQW pin offers selectable frequencies via register-controlled RS1/RS0 bits, while STOP bit enables RTC count chain halt without stopping the oscillator.

Key Specifications

Pinout & Package

PT7C4363BQ1WEX is housed in an 8-pin SOIC (W) package (5.3 mm × 5.3 mm, 1.27 mm pitch), Pb-free and RoHS-compliant, optimized for automotive thermal and vibration requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with RV-3032-C3 and PCF2129A, PT7C4363BQ1WEX uniquely balances crystal flexibility (100 kΩ ESR support), dual alarm/timer interrupt capability, and AEC-Q100 PPAP readiness - making it optimal for cost-sensitive, function-rich automotive modules requiring field-proven reliability and design reuse across BCM, TCU, and ADAS platforms.

Availability

PT7C4363BQ1WEX is available at Aetrix Electronics and suitable for automotive infotainment head units, ADAS domain controllers, and body control modules requiring stable component supply, long-term lifecycle assurance, and IATF 16949 traceability.

Supply support for PT7C4363BQ1WEX 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and integrated circuits, specializing in high-reliability solutions for automotive, industrial, and computing markets.

The PT7C4363BQ1WEX belongs to Diodes' automotive-qualified RTC product line, designed specifically for AEC-Q100-compliant timing functions in harsh-environment vehicle electronics where precision, low power, and functional safety readiness are critical.

FAQ

What crystal specifications are required for reliable operation?

The PT7C4363BQ1WEX requires a 32.768 kHz tuning-fork crystal with load capacitance of 12.5 pF and series resistance ≤100 kΩ. External capacitors C1 = 20 pF (X1-to-GND) and C2 = 0 pF (X2-to-GND) are recommended per Diodes' layout guidelines. Crystal traces must be short, shielded from RF noise, and isolated from switching regulators to ensure ±2 ppm accuracy over temperature.

How does the oscillator fail detect (OSF) flag function in system diagnostics?

The OSF bit (bit 7 of Seconds register) is automatically set to '1' when the oscillator stops or fails to start, indicating loss of timekeeping integrity. Host firmware must read this flag at power-up and after any suspected crystal disturbance; if asserted, the RTC registers must be reinitialized and time manually corrected before resuming operation.

Can the alarm and timer interrupts share the same INT pin without conflict?

Yes - both alarm (AF) and timer (TF) flags assert the same open-drain INT pin low. The host MCU distinguishes sources by reading the Control/Status Register 2 (address 01h): AF and TF bits are separately latched and cleared via write-0, allowing independent acknowledgment and handling of each event type within a single ISR.

Is the PT7C4363BQ1WEX pin-compatible with the legacy PT7C4363?

Yes - PT7C4363BQ1WEX is a drop-in replacement for PT7C4363, sharing identical pinout, register map, and electrical characteristics. Key enhancements include improved high-ESR crystal support and updated AEC-Q100 qualification documentation; no PCB or firmware changes are required for migration.