Analog Devices DS3800 Advanced NV SRAM Battery Cover

Analog Devices DS3800 Advanced NV SRAM Battery Cover

DESCRIPTION

The DS3800 Battery Cap is a snap–on lithium power source for Dallas Semiconductors 40mm ball grid array (BGA) Nonvolatile SRAM modules. After a host BGA module has been soldered in place and cleaned, the DS3800 Battery Cap is snapped onto the module to serve as the secondary power supply.

The Battery Cap is keyed to prevent incorrect attachment and is designed to maintain mechanical and electrical contact with its host module even during severe shock and vibration. Electrically, the DS3800 battery is connected to the host BGA module with gold–plated round pins in the Battery Cap inserted into goldplated receptacles on the BGA. Mechanically, four flanges on the DS3800 tightly grip the BGA module board to prevent Cap removal, while corner features in the Cap prevent lateral movement of the Cap while it is attached to its host BGA module.

Core functions and positioning

The DS3800 is not a standalone electronic component, but a backup power supply component designed specifically for 40mm BGA packaged NV SRAM modules. Its core functions and values are as follows:

Backup power supply: Equipped with a built-in primary lithium battery, it provides continuous power supply to the NV SRAM module in case of power interruption, preventing data loss and adapting to sudden power outages, power fluctuations, and other situations in industrial scenarios;

High temperature protection design: adopting the "post installation" mode - after the BGA module is surface mounted (reflow soldering) and cooled and cleaned, the battery cover is fastened and installed to avoid welding high temperature (usually above 200 ℃) damaging the lithium battery, solving the problem of high temperature failure of traditional integrated power modules;

Anti harsh environment connection: It is tightly connected to the BGA module through four snap flanges, forming a semi permanent mechanical connection. Even in severe impact and vibration environments (such as industrial equipment operation and car driving), it can maintain stable mechanical and electrical connections and avoid power interruption;

Anti mistake installation and easy maintenance: The battery cover is designed with a positioning key (Keyed) to prevent reverse or misplaced installation; If disassembly is required, the snap flange can be broken, balancing installation reliability and flexibility for later maintenance.

Electrical and battery characteristics

（1） Core electrical parameters

Parameter category specification requirements

Working temperature range -40 ℃~+85 ℃ (industrial grade temperature range, covering the vast majority of industrial and automotive electronic scenarios)

Non working temperature range -40 ℃~+85 ℃ (temperature tolerance during storage and transportation to avoid low-temperature freezing cracking or high-temperature leakage)

Electrical connection method: The battery cover is equipped with gold-plated circular pins, which are inserted into the gold-plated socket of the BGA module to achieve low impedance and high reliability power supply connection

（2） Core characteristics of batteries

The built-in lithium primary battery serves as the core power supply component of the module, and its performance parameters directly determine its data retention capability

Specific specifications of battery parameters

Nominal capacity 400 mAh (primary lithium battery, non rechargeable)

Chemical system Li (CF) x (lithium carbon fluoride system, with high energy density and low self discharge rate characteristics, suitable for long-term backup power supply)

Data retention life of 8 years @ 25 ℃ (at room temperature, the battery can maintain NV SRAM module data storage for 8 years, and temperature rise will shorten the life)

Safety adapted to the characteristics of lithium primary batteries, without charging function, avoiding the risk of overcharging; The shell has certain protection to prevent battery damage and leakage

Mechanical specifications and installation requirements

（1） Physical dimensions

The DS3800 adopts a compact design and strictly matches the 40mm BGA module size. The specific specifications are as follows (including imperial and metric units):

Size Identification Imperial (IN.) Metric (MM) Remarks

A (maximum width) maximum 1.670 IN. Maximum 42.42 MM matches the width of 40mm BGA module to ensure no protrusion after fastening

B (maximum length) maximum 1.705 IN. maximum 42.42 MM length direction compatible with BGA modules to avoid interference with peripheral components

C (maximum height) maximum 0.505 IN. Maximum 12.76 MM low rise design, suitable for high-density PCB layout, reducing vertical space occupation

（2） Installation and disassembly specifications

Installation timing: The BGA NV SRAM module must be surface mounted (reflow soldering), cooled to room temperature, and cleaned of solder pad residue before installation. Pre installation before soldering is strictly prohibited to prevent high temperature damage to the battery;

Installation method: Align the positioning key and snap the battery cover towards the BGA module until all 4 snap flanges are fully inserted into the module slot, ensuring that the pins are inserted into the socket without looseness;

Dismantling method: If the battery cover or BGA module needs to be replaced, use a tool to break the 4 snap flanges (the flanges are designed for one-time use and need to be replaced with new battery covers after breakage) to separate the battery cover from the module.

Application scenarios and compatibility

（1） Applicable scenarios

The DS3800 is designed specifically for NV SRAM applications that require long-term data backup and can withstand harsh environments. Typical scenarios include:

Industrial control: parameter storage for PLC (Programmable Logic Controller) and DCS (Distributed Control System) to prevent loss of process data due to power outages;

Automotive Electronics: The configuration data and fault code storage of the onboard ECU (Electronic Control Unit) are capable of withstanding vibrations and temperature fluctuations during vehicle operation;

Medical equipment: Temporary data storage for portable diagnostic instruments to ensure that critical detection data is not lost after a power outage.

（2） Compatibility

Only compatible with Analog Devices (formerly Dallas Semiconductors) 40mm Ball Grid Array (BGA) packaged NV SRAM modules, such as DS1230 series, DS1245 series, etc. (module pin definitions need to be confirmed to match battery cover sockets);

Non universal adaptation: Not compatible with NV SRAM modules in other packages (such as QFP, DIP), and does not support non NV SRAM types of memory (such as DRAM, EEPROM).

Key precautions

Battery safety: The built-in battery is a primary lithium battery that is non rechargeable and cannot be short circuited. When discarded, it should be treated as hazardous waste to avoid high temperatures, squeezing, or punctures;

Life limit: The data retention life of 8 years is a typical value at 25 ℃. In practical applications, if the ambient temperature is higher than 25 ℃ for a long time (such as in the engine compartment of a car), the life will be shortened. It is recommended to regularly check and replace the battery cover;

Mechanical strength: The snap flange is made of plastic material, and excessive force should be avoided during installation to prevent the flange from breaking; After installation, avoid frequent plugging or severe impact to prevent pin deformation or socket damage。