Overview
The M48T35Y-70MH6E is a 32 Kb x 8 non-volatile static RAM and real-time clock produced by STMicroelectronics. This monolithic chip is part of the TIMEKEEPER® RAM series, offering a highly integrated battery-backed memory and real-time clock solution. The device is pin and function compatible with JEDEC standard 32 Kb x 8 SRAMs and can easily fit into many ROM, EPROM, and EEPROM sockets, providing the non-volatility of PROMs without special WRITE timing or limitations on the number of WRITEs. The M48T35Y-70MH6E is available in two special packages: the 28-pin, 600 mil DIP CAPHAT™ package and the 28-pin SOIC package with a separate SNAPHAT® housing for the battery and crystal.
Key Specifications
| Parameter | Description | Value |
|---|---|---|
| Memory Size | 32 Kb x 8 | 256 Kbit |
| Supply Voltage (VCC) | Range | 4.5 to 5.5 V |
| Power-Fail Deselect Voltage (VPFD) | Range for M48T35Y | 4.2 V to 4.5 V |
| Battery Backup Switchover Voltage (VSO) | Threshold for battery switchover | Below VPFD (min) |
| Operating Temperature | Range | –40 to 85 °C |
| Package Types | DIP and SOIC | 28-pin DIP CAPHAT™ and 28-pin SOIC with SNAPHAT® housing |
| Clock Accuracy | Automatic corrections for month and year | Valid until 2100 |
| Data Retention | Minimum battery life | At least 7 years |
Key Features
- Integrated ultra-low power SRAM, real-time clock, power-fail control circuit, and battery.
- BYTEWIDE™ RAM-like clock access with BCD coded year, month, day, date, hours, minutes, and seconds.
- Frequency test output for real-time clock and automatic power-fail chip deselect and WRITE protection.
- Self-contained battery and crystal in the CAPHAT™ DIP package or separate SNAPHAT® housing for SOIC package.
- Pin and function compatible with JEDEC standard 32 Kb x 8 SRAMs.
- RoHS compliant – Lead-free second level interconnect.
Applications
- Embedded systems requiring non-volatile memory and real-time clock functionality.
- Industrial control systems where data integrity and timekeeping are critical.
- Automotive systems needing reliable memory and clock functions.
- Medical devices that require accurate timekeeping and data retention.
- Consumer electronics such as set-top boxes, routers, and other network devices.
Q & A
- What is the memory size of the M48T35Y-70MH6E?
The memory size is 32 Kb x 8, which is equivalent to 256 Kbit.
- What are the package options for the M48T35Y-70MH6E?
The device is available in a 28-pin DIP CAPHAT™ package and a 28-pin SOIC package with a separate SNAPHAT® housing for the battery and crystal.
- What is the power-fail deselect voltage range for the M48T35Y?
The power-fail deselect voltage (VPFD) range for the M48T35Y is 4.2 V to 4.5 V).
- How long does the battery retain data in the M48T35Y-70MH6E?
The internal battery retains data for at least 7 years when VCC is less than VSO).
- Is the M48T35Y-70MH6E compatible with standard SRAMs?
Yes, it is pin and function compatible with JEDEC standard 32 Kb x 8 SRAMs).
- What type of clock information does the M48T35Y-70MH6E provide?
The device provides BCD coded year, month, day, date, hours, minutes, and seconds).
- Does the M48T35Y-70MH6E have automatic corrections for leap years?
Yes, it automatically corrects for 28, 29, 30, and 31 day months and is valid until 2100).
- What is the operating temperature range for the M48T35Y-70MH6E?
The operating temperature range is –40 to 85 °C).
- Is the M48T35Y-70MH6E RoHS compliant?
Yes, it is RoHS compliant with lead-free second level interconnect).
- How does the device handle power failure during a WRITE cycle?
During a power failure, the device write protects itself, but a power failure during a WRITE cycle may corrupt data at the currently addressed location).
