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STMicroelectronics M48T201V-85MH1E
- Part No.:
- M48T201V-85MH1E
- Manufacturer:
- STMicroelectronics
- Category:
- Real Time Clocks
- Package:
- 44-BSOP (0.337", 8.56mm Width) requires SNAPHAT
- Datasheet:
-
M48T201V-85MH1E.pdf
- Description:
- IC RTC CLK/CALENDAR PAR 44SOH
- Quantity:
- Payment:
- Shipping:
Inventory:3,179
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Product details
Overview
M48T201V-85MH1E from STMicroelectronics is a 3.3 V TIMEKEEPER® supervisor IC integrating real-time clock (RTC), watchdog timer, programmable alarm, power-fail detection, and battery-backed SRAM interface control. It supports up to 512 K × 8 external low-power SRAM, provides year-2000-compliant date/time tracking with leap-year correction through 2100, and features battery-low flag, microprocessor power-on reset (active during backup), and square-wave output at selectable frequencies (32.768 kHz, 1024 Hz, 64 Hz, 1 Hz). It is used in industrial control panels requiring persistent timekeeping and nonvolatile memory retention during main power loss.
For engineers reviewing the M48T201V-85MH1E datasheet, M48T201V-85MH1E pinout, M48T201V-85MH1E application, or M48T201V-85MH1E equivalent, this device delivers integrated RTC + supervisor functionality in a single 44-pin SOIC with SNAPHAT®-compatible top-mount battery/crystal housing - critical for embedded systems needing guaranteed data retention, deterministic reset behavior, and precise alarm-triggered event logging under brownout conditions.
Technical Context
The M48T201V-85MH1E implements a self-contained RTC subsystem with 16 dedicated TIMEKEEPER® registers mapped into upper SRAM address space (7FFF0h–7FFFFh), accessed identically to standard SRAM bytes. Its dual-reset inputs (RSTIN1/RSTIN2) support independent system and watchdog reset sources, while GCON/ECON outputs actively manage external SRAM enable timing during power transients to prevent corruption.
Power-fail detection operates within a defined VPFD window (2.7–3.0 V) to initiate automatic write-protection and switch to battery backup via VOUT before VCC drops below switchover threshold (VSO). The on-chip oscillator uses an external 32.768 kHz crystal housed in the SNAPHAT® module, with calibration register (7FFF8h) enabling ±127 ppm fine-tuning across temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Supply Range | 3.0 V to 3.6 V - ensures compatibility with 3.3 V logic systems and avoids overvoltage stress on internal regulators. |
| VPFD Range | 2.7 V ≤ VPFD ≤ 3.0 V - defines precise voltage window for power-fail detection and automatic SRAM write-protection activation. |
| Max Access Time (tAVQV) | 85 ns - guarantees sub-100 ns read latency for both RTC registers and external SRAM, supporting high-speed microcontroller interfaces. |
| External RAM Support | Up to 512 K × 8 - enables direct interfacing with standard low-power CMOS SRAMs without glue logic or address decoding complexity. |
| Square Wave Output | Selectable frequencies: 32.768 kHz / 1024 Hz / 64 Hz / 1 Hz - provides flexible timing reference for MCU wake-up, LED blinking, or system synchronization. |
| Battery Backup Current | VOUT supplies ≤100 µA to external SRAM at <0.3 V drop - sustains data retention in attached memory during extended mains outage. |
| Operating Temperature | 0 °C to +70 °C - validated for commercial/industrial ambient environments without derating. |
Pinout & Package
Package: 44-pin SOIC (SOH44, 330 mil width), RoHS-compliant, lead-free second-level interconnect. Designed for direct mating with ST's SNAPHAT® top-housing (e.g., M4Txx-BR12SH) containing lithium coin cell and 32.768 kHz crystal - mounted post-reflow to avoid thermal damage.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A18 | Address Inputs | 19-bit address bus for accessing 512 KB external SRAM and TIMEKEEPER® registers (7FFF0h–7FFFFh). |
| DQ0–DQ7 | Data I/O | Bi-directional 8-bit data bus shared between RTC registers and external SRAM; compatible with standard SRAM timing. |
| E, G, W | Control Inputs | Chip Enable (E), Output Enable (G), Write Enable (W) - standard SRAM control signals; internally decoded to route access to RTC or RAM. |
| ECON, GCON | RAM Control Outputs | Active-low chip and output enable signals sent to external SRAM; dynamically gated during power transitions to prevent corruption. |
| RSTIN1, RSTIN2 | Reset Inputs | Independent asynchronous reset inputs - RSTIN1 for system reset, RSTIN2 for watchdog-triggered reset; both drive open-drain RST output. |
| RST, IRQ/FT, SQW | Outputs | RST (open-drain reset), IRQ/FT (alarm/interrupt or frequency test), SQW (programmable square wave) - all functional in battery-backup mode. |
| VOUT | Battery Power Output | Regulated output supplying ≤100 µA to external SRAM during backup; maintains data retention when VCC fails. |
| VCC, VSS, NC | Supply & No-Connect | VCC (3.0–3.6 V), VSS (ground), and NC pins (no internal connection) - NC pins provide mechanical stability and noise isolation. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated RTC + Supervisor | Single-chip solution combining real-time clock, power-fail detection, watchdog timer, and SRAM interface control - eliminates discrete timing + reset ICs and reduces BOM count. |
| Year-2000 Compliant Calendar | Automatic month/day adjustment including leap-year correction through year 2100 - ensures long-term accuracy without firmware intervention. |
| SNAPHAT®-Ready SOIC | 44-pin SOIC with gold-plated top-edge contacts - enables reliable, keyed, post-SMT mounting of battery/crystal module, avoiding reflow-induced battery degradation. |
| Backup-Mode Alarm & Watchdog | Programmable alarm interrupt and watchdog reset remain fully operational during battery backup - enables fail-safe event logging and recovery even during total AC loss. |
| Microprocessor Power-On Reset | Guaranteed active-low reset pulse ≥200 ms after VCC restoration - ensures deterministic MCU initialization regardless of power ramp rate or noise. |
Applications
| Industrial HMI Panels | Energy Metering Systems |
|---|---|
|
Use Scenario: Human-machine interface panels in factory automation require persistent timestamping of operator actions and alarm events across power cycles. IC Role / Device Role / Timing Role: M48T201V-85MH1E serves as primary RTC and nonvolatile memory supervisor, maintaining accurate time and protecting SRAM-stored logs during brownouts. Use Value: Guarantees time continuity and data integrity without external backup capacitors or secondary controllers - reducing design complexity and field failure risk. |
Use Scenario: Smart electricity meters must record consumption data with precise timestamps and survive grid outages exceeding 72 hours. IC Role / Device Role / Timing Role: Provides battery-backed RTC and alarm-triggered data capture, with VOUT powering metering SRAM during mains failure. Use Value: Enables >10-year calendar accuracy and >5-year data retention using integrated SNAPHAT® lithium cell - meeting IEC 62053-21 compliance requirements. |
| Medical Diagnostic Devices | Network Infrastructure Equipment |
|
Use Scenario: Portable ultrasound or ECG devices log patient session metadata and calibration timestamps that must persist between charging cycles. IC Role / Device Role / Timing Role: Acts as time source and SRAM guard, delivering battery-backed timekeeping and deterministic reset during Li-ion charge/discharge transitions. Use Value: Eliminates need for separate RTC + supervisor ICs, saving PCB area and simplifying thermal management in compact enclosures. |
Use Scenario: Carrier-grade switches and routers require synchronized event logging and firmware update scheduling across redundant power supplies. IC Role / Device Role / Timing Role: Supplies stable 1 Hz or 1024 Hz square wave for system tick generation and drives alarm interrupts for scheduled maintenance tasks. Use Value: Ensures consistent timebase across hot-swappable line cards - critical for NTP stratum alignment and audit-trail traceability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar RTC + supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS1307+DS1232 | Separate RTC (I²C, no SRAM interface) and external supervisor; no integrated GCON/ECON control or battery-backed SRAM management. | Lacks native SRAM supervision - requires external logic to gate SRAM CE/OE during power loss. | Choose only if I²C interface is mandatory and external SRAM control can be implemented with discrete components. |
| M48T35-25MH1F | Same TIMEKEEPER® architecture but 28-pin DIP; supports 256 K × 8 SRAM; VPFD = 4.1–4.5 V (5 V operation); no SNAPHAT® SOIC variant. | Requires through-hole assembly and 5 V supply - incompatible with 3.3 V designs and SMT-only production flows. | Use only for legacy 5 V systems where board real estate allows DIP footprint and SNAPHAT® integration is not required. |
Compared with DS1307+DS1232 and M48T35-25MH1F, the M48T201V-85MH1E uniquely integrates SRAM interface control, battery-backed operation, and SNAPHAT®-ready packaging in a single 3.3 V SOIC - delivering lower system cost, higher reliability, and simplified layout for modern industrial electronics.
Availability
M48T201V-85MH1E is available at Aetrix Electronics and suitable for industrial HMI panels, smart energy meters, medical diagnostic loggers, and carrier-grade network equipment requiring stable component supply, long-term lifecycle support, and guaranteed SNAPHAT® battery compatibility.
Supply support for M48T201V-85MH1E 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 M48T201V-85MH1E belongs to ST's TIMEKEEPER® supervisor product line, engineered specifically to replace discrete RTC + reset + battery-management circuits in systems demanding guaranteed timekeeping, deterministic reset, and seamless SRAM data retention during power failure.
FAQ
Is the M48T201V-85MH1E pin-compatible with the M48T201Y series?
No. While functionally identical, the M48T201V (3.3 V) and M48T201Y (5 V) differ in VPFD thresholds (2.7–3.0 V vs. 4.1–4.5 V) and DC/AC timing parameters. Their pinouts match, but substituting one for the other risks incorrect power-fail detection or timing violation in the target voltage domain.
What SNAPHAT® battery module is required for the M48T201V-85MH1E?
The M48T201V-85MH1E requires the SH-series SNAPHAT® housing (e.g., M4T08-BR12SH or M4T12-BR12SH) containing a 32.768 kHz crystal and either 48 mAh or 120 mAh lithium coin cell. The SOIC's top-edge contacts mate directly with the SH housing's 4-pin interface - no soldering needed.
Can the M48T201V-85MH1E operate without the SNAPHAT® module?
Yes, but only in main-power mode. Without the SNAPHAT® battery/crystal, the RTC and alarm functions are disabled, and VOUT remains inactive. The device still provides power-on reset and basic SRAM interface control, but loses all backup capabilities and timekeeping functionality.
How is the square wave output frequency selected?
The SQW frequency is set by programming bits RS0–RS3 in register 7FFF0h. Valid combinations yield 32.768 kHz (default), 1024 Hz, 64 Hz, or 1 Hz outputs - each usable as a system tick or wake-up signal, and all active during battery backup mode.
M48T201V-85MH1E Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- Timekeeper®
- Package/Case:
- 44-BSOP (0.337", 8.56mm Width) requires SNAPHAT
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Clock/Calendar
- Features:
- Alarm, Leap Year, Square Wave Output, Supervisor, Watchdog Timer, Y2K
- Memory Size:
- -
- Time Format:
- HH:MM:SS (24 hr)
- Date Format:
- YY-MM-DD-dd
- Interface:
- Parallel
- Voltage - Supply:
- 3V ~ 3.6V
- Voltage - Supply, Battery:
- 3V
- Current - Timekeeping (Max):
- 2mA @ 3V ~ 3.6V
- Operating Temperature:
- 0°C ~ 70°C
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 44-SOH
M48T201V-85MH1E FAQ
1.How can I place an order for M48T201V-85MH1E through Aetrix?
Please submit a Request for Quotation (RFQ) for M48T201V-85MH1E 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 M48T201V-85MH1E reliable?
The price and inventory of M48T201V-85MH1E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for M48T201V-85MH1E is usually 5 days.
3.What payment methods are accepted for M48T201V-85MH1E?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for M48T201V-85MH1E transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for M48T201V-85MH1E?
M48T201V-85MH1E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your M48T201V-85MH1E 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 M48T201V-85MH1E?
For technical support, including M48T201V-85MH1E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your M48T201V-85MH1E requirements.
6.How does Aetrix verify that M48T201V-85MH1E is sourced from the original manufacturer or authorized distributors?
All M48T201V-85MH1E 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 M48T201V-85MH1E meets industry standards.
7.What is the process for return or replacement of M48T201V-85MH1E?
All M48T201V-85MH1E units undergo pre-shipment inspection (PSI). If there is an issue with M48T201V-85MH1E, 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 M48T201V-85MH1E part is unused and in its original packaging.
Return procedure for M48T201V-85MH1E:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
M48T201V-85MH1E Tags
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MCP7940N-I/SN
Microchip Technology
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MCP7940MT-I/MNY
Microchip Technology
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PCF85063ATL/1,118
NXP USA Inc.
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MCP7940NT-I/SN
Microchip Technology
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MCP7940NT-I/MS
Microchip Technology
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MCP7940N-I/MS
Microchip Technology
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PCF85063AT/AY
NXP USA Inc.
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PCF85063TP/1Z
NXP Semiconductors
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PCF85063ATT/AJ
NXP USA Inc.
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MCP7940NT-E/SN
Microchip Technology
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MCP7940NT-I/MNY
Microchip Technology
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MCP79400T-I/SN
Microchip Technology
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