Gas, Water and Heat Flow Meters
For meter designs that require robust data storage capable of supporting battery applications, Microchip provides a wide range of low-power and high endurance EEPROM, serial SRAM, and flash memory.
Features
- Low standby power flash memory
- High endurance serial EEPROM
- Industry leading reliability
- Wide operating voltage and temperature
- Unlimited endurance in SPI Serial SRAM
High Endurance Serial EEPROM and Serial SRAM Memory
Since data storage is a critical factor, a reliable memory such as a serial EEPROM has been the industry preference for many years. The 24xxx and 25xxx serial EEPROM devices support an I²C and SPI serial interface respectively. Read more about memory.
Flash Memory
For applications with higher density memory requirements, Microchip’s NOR flash memory products with patented and proprietary SuperFlash® nonvolatile flash memory cells are ideal solution. SuperFlash memory uses a split-gate cell design and a thick-oxide tunneling injector to offer significant cost and reliability benefits to customers. Superior reliability of 100,000 cycles endurance and greater than 100 years of data retention ensures robust and reliable designs for meter applications. Small Sector Architecture enables a system to choose the right amount of data/code to be erased to update contents allowing seamless partition of program and data code occupying less memory space.
Microchip offers multiple interfaces to satisfy different design needs, Parallel Flash offers asynchronous random access through dedicated address bus. SQI™ flash memory reads and writes through a 4-bit multiplexed synchronous serial communication interface enables true low-pin count, high-bandwidth code execute-in-place applications. SPI Flash serial interface is a cost effective option to store the boot loader code, making it available for download into shadow memory upon power-up.
Memory Cell Structure
- No over-erase problem
- Low total power consumption during erase
- Low leakage current during erase
- Small sector architecture
- Faster re-write times
Serial EEPROM/SRAM Products Table
| Product | Type | Bus | Speed | Density | Voltage | Features |
|---|---|---|---|---|---|---|
| 24AA16 | EEPROM | I²C | - | 256 KB | 1.7V-5.5V | >1M Erase/Write cycles |
| 24LC256 | EEPROM | I²C | - | 512 KB | 1.7V-5.5V | >1M Erase/Write cycles |
| 24LC512 | EEPROM | SPI | - | 512 KB | 1.7V-5.5V | >1M Erase/Write cycles |
| 24AA256 | EEPROM | SPI | - | 1 MB | 1.7V-5.5V | >1M Erase/Write cycles |
| 25LC512 | SRAM | SPI | - | 256 KB | 1.8V-5.5V | >1M Erase/Write cycles |
| 25LC1024 | SRAM | SPI | - | 256 KB | 1.8V-5.5V | >1M Erase/Write cycles |
| 23K256 | SRAM | SPI | - | 256 KB | 2.3V-3.6V | Unlimited Erase/Write cycles |
Flash Memory Products
| Product | Bus | Density (bits) |
Operating Voltage |
Typical Standby Current |
Speed | Typical Program/Erase Endurance |
|---|---|---|---|---|---|---|
| SST39VF512/010/020/040 | x8 Parallel | 512K to 4M | 2.7V to 3.6V | 1µA | 55ns, 70ns | 100K cycles |
| SST39VF200A/400A | x16 Parallel | 2M to 4M | 2.7V to 3.6V | 3µA | 55ns, 70ns | 100K cycles |
| SST39VF801C/802C | x16 Parallel | 8M | 2.7V to 3.6V | 3µA | 55ns, 70ns | 100K cycles |
| SST39VF1601C/1602C | x16 Parallel | 16M | 2.7V to 3.6V | 3µA | 70ns | 100K cycles |
| SST39VF3201C/3202C | x16 Parallel | 32M | 2.7V to 3.6V | 3µA | 70ns | 100K cycles |
| SST38VF6401/2/3/4 | x16 Parallel | 64M | 2.7V to 3.6V | 3µA | 70ns | 100K cycles |
| SST39WF400B/800B | x16 Parallel | 4M to 8M | 1.65V to 1.95V | 5µA | 70ns | 100K cycles |
| SST39WF1601/2 | x16 Parallel | 16M | 1.65V to 1.95V | 2µA | 70ns | 100K cycles |




