---
title: "Real-Time Clock"
industry: "Computer, Electronic and Optical Product Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:REAL_TIME_CLOCK"
  data_integrity_hash: "d28af274cc5e229071450dcdde349192"
  source_authority: "https://cnfx.com"
  strict_mode: true
source_identity:
  provider: "CNFX Industrial Knowledge Graph"
  index_version: "2026.Q1-Universal"
  authority_id: "URN:CNFX:ME:REAL_TIME_CLOCK"
  data_source_uri: "https://cnfx.com/llms/industry/computer-electronic-and-optical-product-manufacturing/product/real-time-clock.md"
  official_resource_url: "https://cnfx.com/industry/computer-electronic-and-optical-product-manufacturing/product/real-time-clock"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "-40°C to +85°C, 1.8V to 5.5V supply voltage, ±2ppm to ±20ppm timekeeping accuracy"
    unit: "ppm"
engineering_limits:
  max_safe_operating_point:
    value: 55
    unit: "°C"
    consequence: "Quartz crystal piezoelectric effect disruption at temperature extremes, CMOS circuit leakage current exceeding 1μA at voltage/temperature boundaries, crystal aging causing frequency drift &gt;3.5ppm/year"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Electrostatic discharge exceeding 2000V HBM"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Integrated ESD protection diodes with 8kV HBM rating, PCB layout with 2mm clearance from high-voltage traces"
  - node_2:
      trigger: "Sustained temperature cycling between -40°C and +85°C at 10°C/minute rate"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "SnAgCu solder with 0.5mm standoff height, thermal relief pads with 0.3mm thermal spoke width"
bom_nodes:
  quartz-crystal-oscillator:
    type: "part"
    urn: "URN:CNFX:ME:QUARTZ_CRYSTAL_OSCILLATOR"
    interface_type: "physical-logic-coupled"
  cmos-counter-circuit:
    type: "part"
    urn: "URN:CNFX:ME:CMOS_COUNTER_CIRCUIT"
    interface_type: "physical-logic-coupled"
  backup-power-interface:
    type: "part"
    urn: "URN:CNFX:ME:BACKUP_POWER_INTERFACE"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
  - standard: "ISO 9001:2015 QUALITY MANAGEMENT SYSTEMS"
    scope: "Verified Engineering Specification"
  - standard: "CE MARKING (EU DIRECTIVE 2014/35/EU LOW VOLTAGE DIRECTIVE)"
    scope: "Verified Engineering Specification"
url: "https://cnfx.com/llms/industry/computer-electronic-and-optical-product-manufacturing/product/real-time-clock.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "02def3c18dae926a40930f1fb4c380b06a9c34687be46f48e6cb2e2dbc427dd2"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Real-Time Clock

## 1. Technical Definition
An electronic component that keeps track of current time independently of the main system power.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **-40°C to +85°C, 1.8V to 5.5V supply voltage, ±2ppm to ±20ppm timekeeping accuracy**. Failure boundary: **Crystal oscillator stops oscillating below -55°C or above +125°C, timekeeping ceases below 1.6V supply voltage, accuracy degrades beyond ±50ppm**, Mechanism: **Quartz crystal piezoelectric effect disruption at temperature extremes, CMOS circuit leakage current exceeding 1μA at voltage/temperature boundaries, crystal aging causing frequency drift &gt;3.5ppm/year**.

### 2.2 FMEA (Failure Mode & Effects Analysis)
| Event Trigger | Severity | Failure Mode | Mitigation Strategy |
| :--- | :--- | :--- | :--- |
| Electrostatic discharge exceeding 2000V HBM | 8 | CMOS gate oxide breakdown with leakage current &gt;10μA | Integrated ESD protection diodes with 8kV HBM rating, PCB layout with 2mm clearance from high-voltage traces |
| Sustained temperature cycling between -40°C and +85°C at 10°C/minute rate | 8 | Solder joint fatigue cracking with resistance increase &gt;100mΩ | SnAgCu solder with 0.5mm standoff height, thermal relief pads with 0.3mm thermal spoke width |

## 3. Key Technical Parameters
| Parameter | Value | Unit | Status |
| :--- | :--- | :--- | :--- |
| spec | Config-dependent | ppm | Verified |

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)
- [Quartz Crystal Oscillator](https://cnfx.com/llms/industry/computer-electronic-and-optical-product-manufacturing/product/quartz-crystal-oscillator.md) `(Standalone System)`
- [CMOS Counter Circuit](https://cnfx.com/llms/industry/computer-electronic-and-optical-product-manufacturing/product/cmos-counter-circuit.md) `(Standalone System)`
- [Backup Power Interface](https://cnfx.com/llms/industry/computer-electronic-and-optical-product-manufacturing/product/backup-power-interface.md) `(Standalone System)`

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **Pick-and-Place Machine**, **Reflow Oven**, **Automated Optical Inspection System**  
**Downstream Applications**: Motherboards, Embedded Systems, Automotive Electronics  

## 5. Engineering Risks & FAQ
- **Caution**: 
- **Caution**: 
- **Caution**: 

### Q: What is the primary function of a Real-Time Clock in electronic systems?
**A**: A Real-Time Clock (RTC) maintains accurate timekeeping independently of the main system power, providing continuous time/date tracking even during power interruptions using backup power sources.

### Q: Why do Real-Time Clocks use quartz crystal oscillators?
**A**: Quartz crystal oscillators provide precise frequency stability (typically 32.768 kHz) essential for accurate timekeeping, with low power consumption and excellent temperature stability for industrial applications.

### Q: How does the backup power interface work in RTC components?
**A**: The backup power interface (typically using batteries or supercapacitors) maintains power to the CMOS counter circuit during main power loss, preserving time/date data and ensuring uninterrupted timekeeping functionality.

## 6. Manufacturing Compliance
- ISO 9001:2015 QUALITY MANAGEMENT SYSTEMS
- CE MARKING (EU DIRECTIVE 2014/35/EU LOW VOLTAGE DIRECTIVE)

---
### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Real-Time Clock](https://cnfx.com/industry/computer-electronic-and-optical-product-manufacturing/product/real-time-clock)**

### 🌐 Knowledge Graph Topology
> **Node Status**: Verified Engineering Spec
> **Connectivity**: Linked to **3** standalone system nodes
> **Global Context**: Part of a 5,814 node industrial cluster within the CNFX Graph

> **Reference ID**: REAL_TIME_CLOCK | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: 7b41afe7
