Overview
The M48T35Y-70MH1E, produced by STMicroelectronics, is a highly integrated 32 Kb x 8 non-volatile static RAM and real-time clock. This monolithic chip is designed to provide a battery-backed memory and real-time clock solution. It is pin and function compatible with JEDEC standard 32 Kb x 8 SRAMs, making it easily interchangeable with many ROM, EPROM, and EEPROM sockets. The device offers the non-volatility of PROMs without the need for special WRITE timing or limitations on the number of WRITE operations.
Key Specifications
| Parameter | Description |
|---|---|
| Memory Size | 32 Kb x 8 (256 Kbit) |
| Supply Voltage (VCC) | 4.5 to 5.5 V |
| Power-Fail Deselect Voltage (VPFD) | 4.2 V ≤ VPFD ≤ 4.5 V |
| Package Types | 28-pin SOH28 (SOIC), 28-pin PDIP 28.7 (CAPHAT™ DIP) |
| Battery and Crystal | Self-contained in CAPHAT™ DIP package; SNAPHAT® housing for SOIC package |
| Operating Temperature | Industrial grade: -40°C to 85°C |
| RoHS Compliance | Ecopack3 (Lead-free second level interconnect) |
Key Features
- Integrated ultra low power SRAM, real-time clock, power-fail control circuit, and battery.
- BYTEWIDE™ RAM-like clock access.
- BCD coded year, month, day, date, hours, minutes, and seconds.
- Frequency test output for real-time clock.
- Automatic power-fail chip deselect and WRITE protection.
- Self-contained battery and crystal in the CAPHAT™ DIP package.
- SOIC package provides direct connection for a SNAPHAT® housing containing the battery and crystal.
- SNAPHAT® housing (battery and crystal) is replaceable.
- Pin and function compatible with JEDEC standard 32 Kb x 8 SRAMs.
- RoHS compliant – Lead-free second level interconnect.
Applications
The M48T35Y-70MH1E is suitable for a variety of applications requiring non-volatile memory and real-time clock functionality. These include:
- Industrial control systems.
- Medical devices.
- Aerospace and defense systems.
- Automotive systems.
- Consumer electronics requiring precise timekeeping and data retention.
Q & A
- What is the memory size of the M48T35Y-70MH1E?
The memory size is 32 Kb x 8, which is equivalent to 256 Kbit.
- What are the package options for the M48T35Y-70MH1E?
The device is available in 28-pin SOH28 (SOIC) and 28-pin PDIP 28.7 (CAPHAT™ DIP) packages.
- How does the power-fail protection work?
The device includes automatic power-fail chip deselect and WRITE protection. When VCC falls below the battery backup switchover voltage (VSO), the control circuitry connects the battery to maintain data and clock operation.
- Is the SNAPHAT® housing replaceable?
- What is the operating temperature range for the M48T35Y-70MH1E?
The operating temperature range is -40°C to 85°C for industrial grade devices.
- Is the M48T35Y-70MH1E RoHS compliant?
- How does the real-time clock function in the M48T35Y-70MH1E?
The real-time clock provides BCD coded year, month, day, date, hours, minutes, and seconds. The clock information is updated once per second and can be accessed like any other memory location.
- Can the M48T35Y-70MH1E be used in place of standard SRAMs?
- What is the purpose of the BYTEWIDE™ RAM-like clock access feature?
This feature allows for RAM-like access to the clock information, making it easier to integrate into existing systems.
- How does the frequency test output for the real-time clock work?
The device provides a frequency test output for the real-time clock, allowing for verification of the clock's accuracy.
