PCA8565TS/1,118 - Automotive RTC, 400kHz I2C, TSSOP-8 | NXP
MPN: PCA8565TS/1,118 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.36 | $2.36 |
| 10 | $2.13 | $21.30 |
| 100 | $1.84 | $184.00 |
| 500 | $1.62 | $810.00 |
| 1,000 | $1.45 | $1,450.00 |
PCA8565TS/1,118 Overview
A Real-Time Clock (RTC) is a dedicated integrated circuit that keeps track of current time and date independently of the main processor, typically using an external 32.768 kHz quartz crystal as the time base. RTCs sit in the broader hierarchy of: RTC -> clock/calendar IC -> timing component -> mixed-signal IC -> semiconductor. They are essential in any embedded system that must maintain accurate wall-clock time across power cycles, including battery-backed designs where the RTC continues counting during main supply loss.
Key features of the PCA8565TS include a programmable clock output, interrupt output, integrated voltage-low detector, automatic word-address increment after each read/write, and AEC-Q100 automotive qualification per the NXP product page. The CMOS process and ultra-low standby current make it suitable for always-on systems drawing microamps in backup mode.
Technically, the PCA8565TS uses an I2C slave interface with hardware-fixed slave address, communicates at up to 400 kbit/s (Fast-mode), and integrates a power-on reset, oscillator stop flag, and a trickle-charge disable bit. The BCD-coded time/date registers eliminate software-side binary-decimal conversion overhead on small MCUs.
Typical applications include automotive instrument clusters, body and chassis ECUs, HVAC controllers, smart meters, industrial data loggers, and IoT edge nodes requiring a long-life backup time source. The wide 1.8 V to 5.5 V supply range allows direct connection to single-cell Li-ion, 3.3 V system rails, or 5 V legacy buses without level shifting.
When designing with the PCA8565TS, ensure the 32.768 kHz crystal load capacitance matches the recommended 7 pF internal load (or use external capacitors as needed), keep the crystal traces short and guarded by ground, and reserve a backup supercapacitor or coin cell on VDD to maintain timekeeping across main power loss.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, with a focus on cross-brand pin-compatible RTC substitutes for automotive and industrial designs.
Drop-in alternatives for PCA8565TS/1,118 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PCF8563T/F4
✅ Drop-In📋 Reference alternative (not in catalog)
PCF85063ATT
✅ Drop-In📋 Reference alternative (not in catalog)
PCA85073ADP/Q900Z
✅ Drop-In📋 Reference alternative (not in catalog)
MCP79410-I/SN
✅ Drop-In📋 Reference alternative (not in catalog)
DS1338Z-16I
✅ Drop-In📋 Reference alternative (not in catalog)
PCA8565TS/1,118 Maximum Ratings & Electrical Characteristics
| Manufacturer | NXP Semiconductors |
| Function | Real-Time Clock (RTC) with Calendar |
| Date Format | YY-MM-DD-dd |
| Time Format | HH:MM:SS (24-hour) |
| Interface | I2C, 2-Wire Serial |
| I2C Bus Speed | Up to 400 kbit/s (Fast-mode) |
| Supply Voltage Range | 1.8 V to 5.5 V |
| Operating Temperature Range | -40 C to +125 C |
| Package / Case | 8-TSSOP, 8-MSOP (0.118", 3.00 mm width) |
| Mounting Type | Surface Mount |
| External Crystal Frequency | 32.768 kHz |
| Integrated Features | Programmable clock output, interrupt output, voltage-low detector |
| Automotive Qualification | AEC-Q100 (per NXP product page) |
| Process Technology | CMOS |
| RoHS Status | Compliant |
PCA8565TS/1,118 Pin Configuration
| Pin 1 | OSCI — Oscillator input (32.768 kHz crystal) |
| Pin 2 | OSCO — Oscillator output (32.768 kHz crystal) |
| Pin 3 | INT — Interrupt output (open-drain) |
| Pin 4 | VSS — Ground |
| Pin 5 | SDA — I2C serial data |
| Pin 6 | SCL — I2C serial clock |
| Pin 7 | CLKOE — Clock output enable (active high) |
| Pin 8 | VDD — Positive supply (1.8 V to 5.5 V) |
Typical Applications
PCA8565TS/1,118 is suitable for 7 applications: Automotive Instrument Cluster, Body and Chassis ECU, HVAC Climate Controller, Smart Meter Data Logger, Industrial Data Acquisition System, IoT Edge Sensor Node, Backup Time Source for Security DVR/NVR.
Automotive Instrument Cluster
The PCA8565TS/1,118 provides accurate wall-clock time for automotive instrument clusters where -40 C to +125 C operation and AEC-Q100 qualification are mandatory. The 400 kHz I2C bus connects the RTC to the cluster MCU, while the integrated voltage-low detector flags low-battery conditions before clock corruption occurs. The TSSOP-8 footprint fits behind the cluster PCB, and BCD-coded registers ease read/write overhead on automotive-grade small MCUs. Designers rely on its 1.8 V to 5.5 V supply tolerance to share the same backup rail as the cluster's always-on domain.
Recommended
Body and Chassis ECU
Body and chassis ECUs (BCM, door modules, seat controllers) require always-on timekeeping for wake-up scheduling, fault-log timestamping, and security event correlation. The PCA8565TS/1,118's AEC-Q100 grade and wide temperature range make it a natural fit for these distributed nodes. The integrated interrupt output drives the ECU's wake-up line, eliminating a discrete timer IC. Its low quiescent current extends backup-battery life across weeks of vehicle parking, while the TSSOP-8 footprint eases retrofit onto space-constrained PCBAs.
Recommended
HVAC Climate Controller
HVAC climate controllers use the PCA8565TS/1,118 for time-stamped scheduling, defrost cycle logging, and filter-replacement reminders. The part's -40 C to +125 C operating range covers extreme cabin and engine-bay temperatures, while 400 kHz I2C keeps the bus load light on shared HVAC sensor networks. The programmable clock output can drive a low-frequency timer interrupt for the MCU's low-power wake cycles. AEC-Q100 qualification ensures reliability in vibration-prone dashboard environments.
Recommended
Smart Meter Data Logger
Electricity, water, and gas smart meters require tamper-resistant timekeeping for time-of-use billing and demand-response logging. The PCA8565TS/1,118 provides BCD-coded time/date registers with automatic address increment, allowing the meter MCU to capture all timestamp fields in a single I2C transaction. The integrated voltage-low detector signals low-battery conditions before clock drift occurs. The TSSOP-8 package mounts easily inside the meter's sealed enclosure, and the 1.8 V to 5.5 V supply tolerates long backup-battery discharge curves.
Recommended
Industrial Data Acquisition System
Industrial data loggers and SCADA remote-terminal-units (RTUs) timestamp every sensor sample with millisecond resolution for regulatory compliance and post-event forensics. The PCA8565TS/1,118 supplies wall-clock time in BCD format, simplifying firmware on legacy 8-bit MCUs. The 1.8 V to 5.5 V supply allows direct connection to 24V-bus-derived 3.3 V rails, while the -40 C to +125 C range supports outdoor enclosures and factory-floor deployment. The I2C interrupt pin drives the RTU's wake-up line between scheduled sample intervals.
Recommended
IoT Edge Sensor Node
Battery-powered IoT sensor nodes (smart agriculture, asset trackers, environmental monitors) need sub-microamp standby current to achieve multi-year battery life. The PCA8565TS/1,118's CMOS RTC architecture draws minimal quiescent current, and its programmable clock output drives the sensor MCU's deep-sleep wake-up timer. The 1.8 V to 5.5 V supply lets it run directly from single-cell Li-ion or 2x AA alkaline packs. The TSSOP-8 package and AEC-Q100 grade provide robustness for both indoor and outdoor IoT deployments.
Recommended
Backup Time Source for Security DVR/NVR
Security DVRs and NVRs retain accurate timestamps on recorded video across power cycles for forensic chain-of-custody. The PCA8565TS/1,118 maintains wall-clock time during main PSU loss via a backup supercapacitor or coin cell, and its integrated voltage-low detector flags backup-cell depletion to the host. The 400 kHz I2C bus shares the recorder's main SoC without contention. The wide supply tolerance lets it ride through DVR power-on transients without losing time, and TSSOP-8 fits on the recorder's front-panel PCB.
Recommended
Recommended Products Summary
Engineering reference data for PCA8565TS/1,118 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PCF8563T/F4 | PCF85063ATT | PCA85073ADP/Q900Z | MCP79410-I/SN | DS1338Z-16I |
|---|---|---|---|---|---|---|
| Package | TSSOP-8 (8-MSOP 0.118", 3.00 mm width) | TSSOP-8 - same | TSSOP-8 - same | TSSOP-8 - same | TSSOP-8 - same | TSSOP-8 - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | Microchip Technology | Analog Devices |
| Supply Voltage Range | 1.8 V to 5.5 V | 1.0 V to 5.5 V | 0.9 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V |
| Operating Temperature | -40 C to +125 C | -40 C to +85 C | -40 C to +85 C | -40 C to +125 C | -40 C to +85 C | -40 C to +85 C |
| AEC-Q100 Automotive | Yes | No | No | Yes | No | No |
| Battery-Backup Switchover | No (external required) | No | No | No | Yes (integrated) | No |
| I2C Bus Speed | 400 kbit/s | 400 kbit/s | 400 kbit/s | 400 kbit/s | 400 kbit/s | 400 kbit/s |
| Integrated SRAM (Bytes) | 0 | 0 | 0 | 0 | 64 | 0 |
Key Differentiators
- AEC-Q100 qualified automotive RTC (vs PCF8563T/F4)
- Lower supply voltage range (1.8 V min) (vs PCF85063ATT)
- No integrated battery-backup switchover or SRAM (vs MCP79410-I/SN)
- Hardware-fixed I2C slave address vs. software-configurable peers (vs DS1338Z-16I)
Design Notes
The PCA8565TS/1,118 does not include integrated battery-backup switchover. Designers must add an external P-MOSFET or supervisor IC to switch between main supply and backup cell, otherwise time is lost on every power cycle. The voltage-low detector (VLOW flag) only signals low-battery condition - it does not perform switchover. For designs needing integrated backup, use Microchip MCP79410 instead.
Keep the 32.768 kHz crystal traces short and symmetric, with both OSCI and OSCO traces enclosed by a ground pour. Excessive trace capacitance shifts crystal load capacitance, degrading frequency accuracy below 20 ppm. Place the crystal within 5 mm of OSCI/OSCO pins, avoid routing digital signals across the oscillator area, and verify the crystal's load-capacitance specification matches the PCA8565's 7 pF internal load plus stray PCB capacitance (typically 5-10 pF total).
The I2C SDA/SCL lines require external pull-up resistors (typically 4.7 kohm at 3.3 V) to VDD. Do not omit these resistors or use values below 1 kohm (violates Fast-mode 400 kHz rise-time spec). If the bus is shared with other I2C devices, ensure slave addresses do not collide with the PCA8565TS hardware address (0x51 read / 0xA3, write 0xA2). Add a series resistor or ferrite bead if EMI from switching converters couples into the I2C lines.
Estimated: at room temperature (25 C) and 5 V supply, the PCA8565TS/1,118 draws negligible quiescent current and the TSSOP-8 package dissipates <10 mW. Junction temperature rise is therefore insignificant, and no thermal management is required. However, at +125 C ambient in automotive deployments, verify crystal temperature stability - standard tuning-fork crystals exhibit parabolic frequency vs. temperature curves that may drift 10-20 ppm across the operating range.
Compliance Information
AEC-Q100 qualified per NXP product page. RoHS and REACH compliant. Lead-free and halogen-free. Conflict-minerals compliant per NXP corporate policy.
