DS1213C

Description

The DS1213C SmartSocket is a 28-pin, 600 mil DIP socket with a built-in CMOS controller circuit and an embedded lithium energy source. It accepts a 32K x 8 JEDEC bytewide CMOS static RAM. When the socket is mated with a CMOS RAM, it provides a complete solution o problems associated with memory volatility. The SmartSocket monitors incoming VCC for an out-of- tolerance condition. When such a condition occurs, the internal lithium energy source is automatically switched on and write protection is unconditionally enabled to prevent data corruption.

Using the SmartSocket saves printed circuit board space since the SRAM/SmartSocket combination occupies no more area than the memory alone. The SmartSocket uses only Pins 20 and 28 for RAM control. All other pins are passed straight through. See the DS1213B SmartSocket data sheet for technical details.

DS1213C description

The DS1213C SmartSocket is a 28-pin, 600mil dual in-line package socket with a built-in Complementary Metal Oxide Semiconductor (CMOS) controller circuit and an embedded lithium energy source which is manufactured by Maxim integrated company. It allows a 32k x 8 JEDEC byte wide CMOS static RAM. When the socket DSC1213C is mated with a CMOS RAM, it provides a comprehensive solution of problems associated with memory volatility. This device monitors the incoming Vcc for an out-of-tolerance condition. When a condition like that happens, the internal lithium energy source is automatically going to the switching ON condition and write protection is unconditionally enabled to avoid the corruption of data.

DS1213C Pin Configuration

When we are using the DSC1213C SmartSocket, it saves the space in the printed circuit board since the SRAM/SmartSocket combination inhabits no more area than the memory alone. The DSC123C SmartSocket takes only Pins 20 and 28 for the controlling of RAM. All the other remaining pins are passed straight through.

DS1213C Features

Some of the key features of this device are given below.

·  Standard 32k x 8 CMOS static RAMs are accepted.

·  Embedded lithium energy cell which will keep RAM data

·  Self-contained circuitry which safeguards the data

·  With the proper RAM selection data retention time will be greater than 10 years.

·  Fully optimized gas-tight socket contacts

·  Operating temperature range 0℃ to 70℃

Function of DS1213C

The SmartSocket DS1213C performs five circuit functions necessary for implementing battery backup on a CMOS memory. The first function is the device has a switch that is provided to direct power from the battery or Vcc supply, depending on which is greater. This switch has a voltage drop which will not exceed 0.2V. The second function is power fail detection at input voltages less than 4.75V.DS1213C constantly monitors the Vcc supply. When Vcc falls below 4.75V, a precision comparator detects the condition and inhibits the enabling of the RAM chip.

The third function accomplishes write protection by holding the chip enable signal to the memory to within 0.2V of Vcc or battery supply. If the chip enables signal is active at the time power fail detection occurs, write protection is delayed until after the memory cycle is complete to avoid corruption of data. During nominal power supply conditions, the memory chip enables signal will be passed through to the socket receptacle with a maximum propagation delay of 20 nanoseconds.

The SmartSocket’s fourth function is to check battery status and warn of potential data loss. Each time that Vcc power is restored to the SmartSocket, the battery voltage is compared with a precision comparator. If the battery supply is below 2.0V, the second memory cycle is inhibited. Battery status can therefore be determined by performing a read cycle after powerup to any location in the memory recording the contents of that memory location. A subsequent write cycle can then be executed to the same memory location changing the data. If the next read cycle fails to verify the written data, the contents of the memory are questionable because the battery may not have retained it.

The fifth function is battery redundancy. In many applications data integrity is paramount. The DS1213C has internal batteries. During the battery backup time the battery with the highest voltage is selected for use. If one battery dies, the other automatically takes over. The switch between batteries is transparent to the user. A battery status warning occurs only if both batteries are less than 2.0V. Each of the two lithium cells contains 35mA per hour capacity.

DS1213C Applications

The DS1213C SmartSocket is outdated now, this can be replaced mostly using a pin-compatible, equivalent-density 5V NV SRAM DS1230 module. Below are some of its applications.

·  Motor vehicle crash boxes

·  Data logging applications

·  Some medical equipment’s and high-end servers which needs to store data

5V NV SRAMDS1230 Which replaces DS1213C