M48T59Y-70MH1F

Real Time Clock Overview

The M48T59Y-70MH1F is a non-volatile real-time clock and static RAM integrated circuit manufactured by STMicroelectronics. It combines an 8 Kbit (8 Kbit x 8) SRAM array with a quartz-controlled clock oscillator, power-fail detection, and battery switching circuitry in a single package. The device operates on a parallel interface with a supply voltage range of 4.5 V to 5.5 V and supports a maximum access time of 70 ns. It utilizes a 28-lead SOIC package designed for surface mount assembly, requiring a separate SNAPHAT housing containing the lithium battery and crystal.

Real Time Clock Feature Summary

• Integrated ultra-low power SRAM, real-time clock, and power-fail control circuit
• Automatic power-fail chip deselect and write protection when VCC falls below threshold
• Battery-backed operation with automatic switchover to internal lithium cell
• Programmable alarm output and watchdog timer functionality

Real Time Clock Applications

• Industrial systems requiring non-volatile timekeeping and data retention
• Embedded controllers needing backup memory during power outages
• Telecommunications equipment requiring precise clock synchronization

Real Time Clock Procurement Notes

Verify component status as this product may be obsolete or not recommended for new designs. Confirm availability through authorized distributors. Ensure compatibility with required SNAPHAT battery housing part numbers such as M4T28-BR12SH1 or M4T32-BR12SHx for complete system integration.

Real Time Clock Selection Notes

Select this model for applications requiring 5V logic levels and parallel bus interfaces. The 'Y' suffix indicates a 4.5V to 5.5V operating range. Ensure the design accommodates the separate SNAPHAT housing insertion after reflow soldering to protect the battery from high temperatures. Verify that the 28-SOH package dimensions fit the PCB layout constraints.

Real Time Clock Part Context

This component belongs to the M48T59 Timekeeper series, which provides pin-compatible alternatives in DIP and 3.3V variants. The M48T59Y specifically targets standard 5V systems. It serves as a direct replacement for standard JEDEC 8Kb x 8 SRAMs while adding real-time clock capabilities without special write timing requirements.

Real Time Clock Replacement Considerations

Direct functional equivalents include the M48T59V for 3.3V applications or the M48T59 in DIP packaging. For surface-mount replacements, verify if newer ST RTC families offer compatible pinouts and features, though specific cross-references require datasheet validation.