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STMicroelectronics M48T12-150PC1
- Part No.:
- M48T12-150PC1
- Manufacturer:
- STMicroelectronics
- Category:
- Real Time Clocks
- Package:
- 24-DIP Module (0.600", 15.24mm)
- Datasheet:
-
M48T12-150PC1.pdf
- Description:
- IC RTC CLK/CALENDAR PAR 24DIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,900
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Product details
Overview
M48T12-150PC1 from STMicroelectronics is a 5.0 V, 16 Kbit (2 Kb × 8) non-volatile TIMEKEEPER® SRAM integrating ultra-low-power static RAM, real-time clock, and power-fail control circuitry in a single CAPHAT™ DIP package. It delivers BCD-coded timekeeping (year/month/day/hour/minute/second), ±1 minute/month accuracy at 25 °C, software-controlled clock calibration, and automatic WRITE protection during VCC decay - used in industrial control panels requiring persistent timestamping and battery-backed memory retention.
For engineers reviewing the M48T12-150PC1 datasheet, M48T12-150PC1 pinout, M48T12-150PC1 application, or M48T12-150PC1 equivalent, key selection criteria include its BYTEWIDE™ SRAM interface compatibility with JEDEC 2K×8 SRAMs, VPFD voltage window (4.2–4.5 V), integrated 32.768 kHz crystal + lithium cell, and BiPORT™ clock register mapping at addresses 7F8h–7FFh.
Technical Context
The M48T12-150PC1 integrates a 2048 × 8 SRAM array and quartz-controlled RTC on one die, with clock data stored in eight dedicated BiPORT™ memory locations (7F8h–7FFh) updated once per second. Its power-fail detection circuit monitors VCC continuously and initiates battery switchover when VCC drops below VSO (~3 V), while enforcing WRITE protection within the 4.2–4.5 V VPFD window.
Timekeeping uses BCD format with automatic leap-year correction through 2100, and calibration is implemented via five-bit programmable register (0–31 steps) that adds/subtracts oscillator cycles at the ÷256 stage - enabling ±5.5 to ±2.75 min/month adjustment range. The STOP bit in the seconds register halts oscillator operation to conserve battery during shelf storage.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 16 Kbit (2 Kb × 8); provides byte-wide parallel access identical to standard JEDEC SRAMs for drop-in replacement in legacy sockets. |
| RTC accuracy | ±1 minute/month at 25 °C; achieved via factory-trimmed 32.768 kHz crystal and software-calibratable counter correction. |
| VPFD range | 4.2 V ≤ VPFD ≤ 4.5 V; defines precise voltage window where automatic WRITE protection activates during brownout. |
| Access time | 150 ns (–150 speed grade); guarantees valid data output within 150 ns after address stabilization under VCC = 4.5–5.5 V. |
| Battery life | ≥10 years data/clock retention; enabled by integrated lithium button cell and low-quiescent-current RTC circuitry. |
| Package | PCDIP24 (24-pin plastic DIP, 600 mil); includes embedded crystal and battery in CAPHAT™ housing for self-contained operation. |
| Operating temp | 0 °C to +70 °C; validated for industrial ambient conditions without derating. |
Pinout & Package
Package: PCDIP24 - 24-pin plastic dual in-line package with integrated lithium battery and 32.768 kHz quartz crystal in CAPHAT™ housing. Dimensions conform to JEDEC MS-001AC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A10 | Address inputs | 11-bit address bus selecting one of 2048 memory locations; also used to access clock registers at 7F8h–7FFh. |
| DQ0–DQ7 | Data I/O | Bi-directional 8-bit data bus; supports BYTEWIDE™ read/write of SRAM and RTC registers using standard SRAM timing. |
| E | Chip enable | Active-low signal enabling memory access; initiates READ/WRITE cycles and triggers power-fail detection sampling. |
| G | Output enable | Active-low three-state control for DQ0–DQ7; must be high during WRITE to prevent bus contention. |
| W | WRITE enable | Active-low signal controlling WRITE mode; falling edge (with E low) latches data into selected location. |
| VCC | Supply voltage | 5.0 V nominal (4.5–5.5 V range); powers SRAM/RTC; monitored for VPFD detection and battery switchover. |
| VSS | Ground | Reference return path for all internal circuits; required for stable RTC oscillation and SRAM retention. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated CAPHAT™ package | Self-contained 24-pin DIP with factory-mounted crystal and lithium cell - eliminates external component sourcing and layout complexity. |
| BYTEWIDE™ clock access | RTC registers mapped to standard SRAM addresses (7F8h–7FFh), enabling time reads/writes using existing memory bus protocols without added logic. |
| Software clock calibration | Five-bit calibration register adjusts RTC rate in ±4.068/–2.034 ppm steps, supporting field tuning for temperature-induced drift without hardware changes. |
| Automatic power-fail protection | VCC monitoring triggers immediate WRITE disable and high-Z outputs when voltage enters 4.2–4.5 V VPFD window - prevents corruption during brownout. |
| BOK flag monitoring | Battery OK status bit alerts system firmware at power-up if cell voltage is insufficient, blocking first WRITE until confirmed healthy. |
Applications
| Industrial HMI Panels | Energy Metering Systems |
|---|---|
|
Use Scenario: Embedded human-machine interface in factory automation panels requiring persistent event logging with accurate timestamps across power cycles. IC Role / Device Role / Timing Role: Non-volatile SRAM stores configuration and alarm history; RTC provides BCD-formatted wall-clock time synchronized to mains frequency. Use Value: Eliminates need for external RTC + backup battery + EEPROM, reducing BOM count and PCB footprint while guaranteeing 10-year timestamp integrity. |
Use Scenario: Smart electricity meters recording kWh consumption and tariff-switching events with legally traceable time stamps. IC Role / Device Role / Timing Role: TIMEKEEPER® maintains metrology-grade timekeeping; SRAM stores billing intervals and tamper logs with battery-backed retention. Use Value: Meets IEC 62053-21 accuracy requirements via ±1 min/month RTC stability and automatic leap-year correction through 2100. |
| Medical Diagnostic Devices | Network Infrastructure Equipment |
|
Use Scenario: Portable ultrasound or ECG units storing patient session metadata and diagnostic timestamps during battery-only operation. IC Role / Device Role / Timing Role: Provides continuous clock operation during AC loss; SRAM retains last-saved waveform headers and calibration offsets. Use Value: Ensures regulatory-compliant audit trails with no time gaps, leveraging integrated lithium cell rated for ≥10 years shelf life. |
Use Scenario: Carrier-grade switches/routers maintaining uptime logs, NTP synchronization references, and firmware update timestamps across redundant power supplies. IC Role / Device Role / Timing Role: Serves as primary time source for system logging; VPFD-triggered WRITE protection prevents log corruption during supply transients. Use Value: Enables deterministic failover timing and forensic log analysis by preserving monotonic, battery-backed time across 10+ years of operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar non-volatile RTC+SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS1642-150+ (Maxim Integrated) | Same 2K×8 SRAM + RTC architecture; requires external crystal and battery; VPFD = 4.25–4.75 V; no integrated CAPHAT™ package. | Demands additional PCB area and assembly steps for crystal/battery placement; lacks factory-calibrated accuracy guarantee. | Select when board-level customization of crystal loading or battery chemistry is required; not suitable for space-constrained designs. |
| M48T35Y-150PC1 (STMicroelectronics) | Higher-density 64 Kbit (8K×8) variant; same CAPHAT™ package, VPFD (4.2–4.5 V), and calibration engine; extended temperature range (–40 to +85 °C). | Supports wider thermal environments and larger data buffers; pin-compatible but occupies more memory map space. | Choose for new designs needing future scalability or extended temp operation; retains full software compatibility with M48T12. |
Compared with DS1642-150+, M48T12-150PC1 reduces system integration effort via embedded crystal/battery and tighter VPFD tolerance; versus M48T35Y-150PC1, it offers optimal cost/size balance for 16 Kbit memory needs without over-provisioning.
Availability
M48T12-150PC1 is available at Aetrix Electronics and suitable for industrial HMI panels, energy metering systems, and medical diagnostic devices requiring stable component supply, long-term lifecycle support, and guaranteed battery-backed timekeeping performance.
Supply support for M48T12-150PC1 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, analog ICs, MEMS, and power management solutions for industrial, automotive, and consumer markets.
The TIMEKEEPER® product line delivers integrated RTC+SRAM devices optimized for applications demanding persistent timekeeping and data retention without external support components - targeting industrial control, metering, and infrastructure equipment.
FAQ
What is the function of the BOK (Battery OK) flag in M48T12-150PC1?
The BOK flag indicates whether the integrated lithium battery voltage remains sufficient for reliable RTC and SRAM operation. It is automatically set at power-up if battery voltage falls below threshold, blocking the first WRITE attempt until cleared by successful write operation. This prevents data corruption due to marginal backup power and enables firmware to trigger low-battery alerts.
How does the M48T12-150PC1 handle leap-year correction?
The M48T12-150PC1 performs automatic leap-year correction in hardware for years through 2100. Its RTC logic recognizes February 29 in leap years (divisible by 4, excluding years divisible by 100 unless also divisible by 400) and adjusts date rollover accordingly - no firmware intervention is required for correct day-of-month sequencing.
Can the M48T12-150PC1 be used as a direct replacement for standard 2K×8 SRAMs?
Yes - the M48T12-150PC1 is pin- and function-compatible with JEDEC-standard 2K×8 SRAMs. All control signals (E, G, W), address/data buses, and timing parameters match industry norms. When VCC is stable, it operates identically to conventional SRAM; RTC functionality resides only in reserved address range 7F8h–7FFh.
What happens during a power failure while writing to the M48T12-150PC1?
If VCC drops into the 4.2–4.5 V VPFD window during a WRITE cycle, the device immediately disables WRITE capability and places all outputs in high-impedance state. Only the currently addressed memory location may be corrupted; the remainder of SRAM contents and RTC registers remain intact and protected by battery power.
M48T12-150PC1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- Timekeeper®
- Package/Case:
- 24-DIP Module (0.600", 15.24mm)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Clock/Calendar
- Features:
- Leap Year
- Memory Size:
- -
- Time Format:
- HH:MM:SS (24 hr)
- Date Format:
- YY-MM-DD-dd
- Interface:
- Parallel
- Voltage - Supply:
- 4.5V ~ 5.5V
- Voltage - Supply, Battery:
- -
- Current - Timekeeping (Max):
- 3mA @ 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C
- Mounting Type:
- Through Hole
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 24-PCDIP, CAPHAT®
M48T12-150PC1 FAQ
1.How can I place an order for M48T12-150PC1 through Aetrix?
Please submit a Request for Quotation (RFQ) for M48T12-150PC1 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 M48T12-150PC1 reliable?
The price and inventory of M48T12-150PC1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for M48T12-150PC1 is usually 5 days.
3.What payment methods are accepted for M48T12-150PC1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for M48T12-150PC1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for M48T12-150PC1?
M48T12-150PC1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your M48T12-150PC1 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 M48T12-150PC1?
For technical support, including M48T12-150PC1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your M48T12-150PC1 requirements.
6.How does Aetrix verify that M48T12-150PC1 is sourced from the original manufacturer or authorized distributors?
All M48T12-150PC1 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 M48T12-150PC1 meets industry standards.
7.What is the process for return or replacement of M48T12-150PC1?
All M48T12-150PC1 units undergo pre-shipment inspection (PSI). If there is an issue with M48T12-150PC1, 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 M48T12-150PC1 part is unused and in its original packaging.
Return procedure for M48T12-150PC1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
M48T12-150PC1 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
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