My Inquiry
My Account
Renesas ISL12027IB27Z-T
- Part No.:
- ISL12027IB27Z-T
- Manufacturer:
- Renesas
- Category:
- Real Time Clocks
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
ISL12027IB27Z-T.pdf
- Description:
- IC RTC CLK/CALENDAR I2C 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,564
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
ISL12027IB27Z-T from Renesas (formerly Intersil) is a low-power real-time clock/calendar IC with integrated 512×8-bit EEPROM, dual non-volatile alarms, on-chip oscillator compensation, CPU supervisor (POR/WDT), and intelligent battery backup switching. It operates from 2.7V to 5.5V main supply and retains timekeeping down to 1.8V on VBAT, using an external 32.768kHz crystal. It delivers ±30ppm digital frequency adjustment and supports I²C at 400kHz for utility metering and industrial control systems.
For engineers reviewing the ISL12027IB27Z-T datasheet, ISL12027IB27Z-T pinout, ISL12027IB27Z-T application, or ISL12027IB27Z-T equivalent, this page provides verified timing accuracy, battery-switching behavior, alarm repeat modes, EEPROM BlockLock™ protection levels, and VDD/VBAT power-control differences between ISL12027 and ISL12027A variants.
Technical Context
The ISL12027IB27Z-T implements a fully autonomous RTC subsystem with leap-year-corrected calendar logic valid through 2099, volatile time registers (BCD format), and two independent non-volatile alarm registers supporting second/minute/hour/day-of-week/date/month match conditions and periodic interrupt modes. Its oscillator compensation uses a 64-position digitally controlled trim capacitor and six discrete frequency settings for ±30ppm calibration.
Power management includes legacy-mode battery switchover (VBAT > VDD required), a 2.63V VRESET threshold, open-drain RESET output with 250ms power-up delay, and watchdog timer with three timeout options (225/250/275ms). The 512×8-bit EEPROM is organized in 32 pages of 16 bytes each and features eight BlockLock™ protection modes for secure configuration storage.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| RTC Accuracy | ±30ppm digitally adjustable via 64-step trim capacitor - enables field calibration without external components |
| I²C Interface Speed | 400kHz maximum - supports fast host communication without timing margin violations |
| Battery Supply Current | 800–1000nA at VBAT = 1.8V - ensures >10-year coin-cell operation in standby |
| EEPROM Endurance | >2,000,000 write cycles per byte - suitable for frequent logging or parameter updates |
| Data Retention | 50 years at ≤+75°C - guarantees long-term reliability in sealed industrial enclosures |
| VDD Operating Range | 2.7V to 5.5V - compatible with 3.3V and 5V system rails without level-shifting |
| VBAT Standby Range | 1.8V to 5.5V - maintains full RTC/calendar function during brownout or main power loss |
Pinout & Package
ISL12027IB27Z-T is housed in an 8-lead SOIC package (Pb-free, RoHS compliant, JEDEC MO-153, pkg drawing M8.15) with standard 1.27mm pitch and 5.0mm × 4.0mm footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| X1 | Oscillator input | Inverting amplifier input for 32.768kHz crystal; accepts direct 32.768kHz square-wave drive |
| X2 | Oscillator output | Inverting amplifier output; drives crystal only - no external loading permitted |
| VBAT | Backup supply input | Enables seamless switchover to battery/supercap when VDD falls below VTRIP (1.8–2.6V) |
| VDD | Main power supply | Primary 2.7–5.5V rail; powers all logic, EEPROM, and I²C interface |
| RESET | Open-drain reset output | Active-low signal asserting on VDD undervoltage or watchdog timeout; requires 5kΩ pull-up |
| SCL | I²C clock input | Always-active input buffer; must use same voltage source as VDD for pull-up resistor |
| SDA | I²C bidirectional data | Open-drain I/O; supports wire-OR with other I²C devices; slope-controlled fall time for 400kHz compliance |
| GND | Analog/digital ground | Common reference for all internal circuits; must be low-impedance connection to PCB ground plane |
Key Features
| Feature | Design Value |
|---|---|
| Dual non-volatile alarms | Two independently configurable alarms with repeat mode - enables scheduled wake-up or periodic status polling without host intervention |
| On-chip oscillator compensation | 64-position digital trim + 6 frequency steps (±30ppm) - eliminates need for external load capacitors or manual tuning |
| BlockLock™ EEPROM protection | 8 programmable lock modes across 32 pages - allows selective write-protection of calibration data while leaving user logs writable |
| Legacy power control mode | BSW = 1 default; requires VBAT > VDD for backup activation - ensures deterministic switchover in metering applications with supercap backup |
| Low-voltage RTC operation | Full timekeeping functional at VBAT ≥1.8V - maintains calendar accuracy during extended brownouts or battery depletion |
Applications
| Smart Utility Metering | HVAC Energy Management |
|---|---|
Use Scenario: Time-stamped energy consumption logging in electricity/water/gas meters with tamper-resistant audit trails. IC Role / Device Role / Timing Role: Primary RTC/calendar with battery-backed timekeeping and EEPROM storage for billing intervals and firmware version stamps. Use Value: 50-year data retention and >2M EEPROM endurance ensure regulatory compliance over full product lifetime without field replacement. |
Use Scenario: Scheduling of heating/cooling cycles, demand-response events, and maintenance alerts in commercial HVAC controllers. IC Role / Device Role / Timing Role: System timekeeper and alarm generator triggering relay control based on day-of-week, hour, and seasonal date ranges. Use Value: Dual repeat-mode alarms eliminate microcontroller polling overhead and reduce system power by enabling deep-sleep host operation. |
| Industrial Network Routers | Medical Diagnostic Equipment |
Use Scenario: Accurate timestamping of SNMP traps, firmware update logs, and security event records in managed network infrastructure. IC Role / Device Role / Timing Role: Trusted time source synchronized to NTP server boot-time, maintaining continuity during brief AC outages via VBAT. Use Value: 2.63V VRESET threshold and 250ms POR delay prevent spurious resets during line transients common in factory-floor power distribution. |
Use Scenario: Patient session tracking, calibration timestamping, and audit-log generation in portable ultrasound or ECG devices. IC Role / Device Role / Timing Role: Secure timekeeping and protected EEPROM storage for FDA-mandated device usage history and calibration certificates. Use Value: BlockLock™ protection prevents unauthorized modification of critical calibration parameters while allowing field-serviceable log writes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar real-time clock/calendar with EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS3231SN#T&R | Integrated TCXO (±2ppm), higher accuracy; no EEPROM; different I²C address (0x68 vs 0x6F); 16-pin SOIC | Superior timing stability in temperature-variable environments; lacks non-volatile alarm storage and BlockLock™ | Select for precision timing where EEPROM and alarms are handled externally or not required |
| PCF2129AT | Integrated oscillator compensation (±5ppm typical); 256B EEPROM; no BlockLock™; 8-pin TSSOP only; VDD min = 1.8V | Lower power (100nA VBAT current); no legacy/standard mode distinction; simpler register map | Select for space-constrained designs needing ultra-low battery drain and moderate accuracy without advanced EEPROM security |
Compared with DS3231SN#T&R and PCF2129AT, the ISL12027IB27Z-T uniquely combines ±30ppm field-adjustable RTC accuracy, dual non-volatile alarms, 512×8-bit BlockLock™ EEPROM, and legacy-mode battery switchover - making it optimal for cost-sensitive industrial meters requiring long-term data integrity and deterministic power-fail response.
Availability
ISL12027IB27Z-T is available at Aetrix Electronics and suitable for smart utility metering, HVAC energy management, and industrial network routers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for ISL12027IB27Z-T 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
Renesas Electronics Corporation acquired Intersil in 2017 and maintains full technical and supply chain support for the ISL12027 family. Renesas is a global leader in microcontrollers, analog, and power solutions for industrial and automotive markets.
The ISL12027 product line was designed specifically for high-reliability, battery-backed timekeeping in utility infrastructure and industrial control systems - emphasizing EEPROM security, long-term data retention, and robust power-fail supervision.
FAQ
What is the VBAT trip threshold and hysteresis for ISL12027IB27Z-T?
The ISL12027IB27Z-T has a nominal VBAT mode threshold (VTRIP) of 2.63V with 50mV hysteresis (VBATHYS). This ensures clean switchover from VDD to battery backup during brownout conditions and prevents oscillation near the trip point. The device remains fully operational on VBAT down to 1.8V, and the VTRIP value is fixed per ordering option - ISL12027IB27Z-T is specified for 2.63V VRESET and legacy-mode (BSW=1) operation.
Does ISL12027IB27Z-T support I²C communication during battery backup mode?
No, I²C communication is disabled during battery backup mode (BAT = 1) for ISL12027IB27Z-T. The SCL and SDA pins are high-impedance, and the interface does not respond to start conditions. This is a defined behavior per the datasheet's "I2C Communications During Battery Backup and LVR Operation" section (page 24). Host access to RTC and EEPROM registers resumes only after return to VDD-powered operation.
How many EEPROM write cycles can ISL12027IB27Z-T endure, and what is its data retention?
The ISL12027IB27Z-T guarantees >2,000,000 write cycles per EEPROM byte and 50 years of data retention at temperatures ≤+75°C. These specifications apply to the full 512×8-bit array organized in 32 pages of 16 bytes each. BlockLock™ protection does not affect endurance or retention - it only controls write-enable permissions per page group.
What oscillator compensation capability does ISL12027IB27Z-T provide?
The ISL12027IB27Z-T integrates a 64-position digitally controlled trim capacitor and six discrete digital frequency adjustment settings covering ±30ppm total range. This allows precise calibration of the 32.768kHz crystal without external components. Compensation is applied to the internal oscillator loop and is effective across the full -40°C to +85°C operating temperature range.
Is ISL12027IB27Z-T pin-compatible with ISL12027A variants?
No, ISL12027IB27Z-T is not pin-compatible with ISL12027A variants due to differing power control logic - ISL12027 uses Legacy Mode (BSW = 1), while ISL12027A uses Standard Mode (BSW = 0). Though both share identical pinout and package, their VBAT switchover behavior, RESET assertion conditions, and I²C timing under low-VDD differ. Interchange requires firmware and power-design validation.
ISL12027IB27Z-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Clock/Calendar
- Features:
- Alarm, Leap Year, Supervisor, Watchdog Timer
- Memory Size:
- -
- Time Format:
- HH:MM:SS (12/24 hr)
- Date Format:
- YY-MM-DD-dd
- Interface:
- I2C, 2-Wire Serial
- Voltage - Supply:
- 2.7V ~ 5.5V
- Voltage - Supply, Battery:
- 1.8V ~ 5.5V
- Current - Timekeeping (Max):
- 10µA ~ 20µA @ 2.7V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 8-SOIC
ISL12027IB27Z-T FAQ
1.How can I place an order for ISL12027IB27Z-T through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL12027IB27Z-T on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for ISL12027IB27Z-T reliable?
The price and inventory of ISL12027IB27Z-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL12027IB27Z-T is usually 5 days.
3.What payment methods are accepted for ISL12027IB27Z-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL12027IB27Z-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL12027IB27Z-T?
ISL12027IB27Z-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL12027IB27Z-T order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for ISL12027IB27Z-T?
For technical support, including ISL12027IB27Z-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL12027IB27Z-T requirements.
6.How does Aetrix verify that ISL12027IB27Z-T is sourced from the original manufacturer or authorized distributors?
All ISL12027IB27Z-T products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ISL12027IB27Z-T meets industry standards.
7.What is the process for return or replacement of ISL12027IB27Z-T?
All ISL12027IB27Z-T units undergo pre-shipment inspection (PSI). If there is an issue with ISL12027IB27Z-T, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The ISL12027IB27Z-T part is unused and in its original packaging.
Return procedure for ISL12027IB27Z-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ISL12027IB27Z-T Tags
-
MCP7940N-I/SN
Microchip Technology
-
MCP7940MT-I/MNY
Microchip Technology
-
PCF85063ATL/1,118
NXP USA Inc.
-
MCP7940NT-I/SN
Microchip Technology
-
MCP7940NT-I/MS
Microchip Technology
-
MCP7940N-I/MS
Microchip Technology
-
PCF85063AT/AY
NXP USA Inc.
-
PCF85063TP/1Z
NXP Semiconductors
-
PCF85063ATT/AJ
NXP USA Inc.
-
MCP7940NT-E/SN
Microchip Technology
-
MCP7940NT-I/MNY
Microchip Technology
-
MCP79400T-I/SN
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
