DS1990A iButton: Where & How to use
IC, SERIAL NUMBER IBUTTON, F5 IBUTTON - More Details
iButtons DS1990A is an amazing compact device introduced exclusively by Maxim integrated. Furthermore, there is a huge range of Semiconductors, Capacitors, Resistors and ICs in stock. Welcome RFQ.
DS1990A Pinout

DS1990A Pinout
| Pin Number | Pin Name | Description |
| 1 | Signal/IO | Data is sent and received through this pin a.k.a IO pin |
| 2 | Ground | Common ground pin |
DS1990A CAD Model
Footprint

DS1990A Footprint
DS1990A General Description
The DS1990A serial number iButton is a rugged data carrier that serves as an electronic registration number for automatic identification. Data is transferred serially through the 1-Wire® protocol, which requires only a single data lead and a ground return. Every DS1990A is factory lasered with a guaranteed unique 64-bit registration number that allows for absolute traceability. The durable stainless-steel iButton package is highly resistant to environmental hazards such as dirt, moisture, and shock.
Specifications
- TypeParameter
- Factory Lead Time6 Weeks
- Mount
In electronic components, the term "Mount" typically refers to the method or process of physically attaching or fixing a component onto a circuit board or other electronic device. This can involve soldering, adhesive bonding, or other techniques to secure the component in place. The mounting process is crucial for ensuring proper electrical connections and mechanical stability within the electronic system. Different components may have specific mounting requirements based on their size, shape, and function, and manufacturers provide guidelines for proper mounting procedures to ensure optimal performance and reliability of the electronic device.
Surface Mount - Number of Pins2
- Memory TypesROM
- Operating Temperature
The operating temperature is the range of ambient temperature within which a power supply, or any other electrical equipment, operate in. This ranges from a minimum operating temperature, to a peak or maximum operating temperature, outside which, the power supply may fail.
-40°C~85°C - Series
In electronic components, the "Series" refers to a group of products that share similar characteristics, designs, or functionalities, often produced by the same manufacturer. These components within a series typically have common specifications but may vary in terms of voltage, power, or packaging to meet different application needs. The series name helps identify and differentiate between various product lines within a manufacturer's catalog.
iButton® - Published2003
- JESD-609 Code
The "JESD-609 Code" in electronic components refers to a standardized marking code that indicates the lead-free solder composition and finish of electronic components for compliance with environmental regulations.
e3 - Pbfree Code
The "Pbfree Code" parameter in electronic components refers to the code or marking used to indicate that the component is lead-free. Lead (Pb) is a toxic substance that has been widely used in electronic components for many years, but due to environmental concerns, there has been a shift towards lead-free alternatives. The Pbfree Code helps manufacturers and users easily identify components that do not contain lead, ensuring compliance with regulations and promoting environmentally friendly practices. It is important to pay attention to the Pbfree Code when selecting electronic components to ensure they meet the necessary requirements for lead-free applications.
yes - Part Status
Parts can have many statuses as they progress through the configuration, analysis, review, and approval stages.
Active - Moisture Sensitivity Level (MSL)
Moisture Sensitivity Level (MSL) is a standardized rating that indicates the susceptibility of electronic components, particularly semiconductors, to moisture-induced damage during storage and the soldering process, defining the allowable exposure time to ambient conditions before they require special handling or baking to prevent failures
1 (Unlimited) - Number of Terminations2
- ECCN Code
An ECCN (Export Control Classification Number) is an alphanumeric code used by the U.S. Bureau of Industry and Security to identify and categorize electronic components and other dual-use items that may require an export license based on their technical characteristics and potential for military use.
EAR99 - Terminal Finish
Terminal Finish refers to the surface treatment applied to the terminals or leads of electronic components to enhance their performance and longevity. It can improve solderability, corrosion resistance, and overall reliability of the connection in electronic assemblies. Common finishes include nickel, gold, and tin, each possessing distinct properties suitable for various applications. The choice of terminal finish can significantly impact the durability and effectiveness of electronic devices.
MATTE TIN - Applications
The parameter "Applications" in electronic components refers to the specific uses or functions for which a component is designed. It encompasses various fields such as consumer electronics, industrial automation, telecommunications, automotive, and medical devices. Understanding the applications helps in selecting the right components for a particular design based on performance, reliability, and compatibility requirements. This parameter also guides manufacturers in targeting their products to relevant markets and customer needs.
Product Identification - Terminal Position
In electronic components, the term "Terminal Position" refers to the physical location of the connection points on the component where external electrical connections can be made. These connection points, known as terminals, are typically used to attach wires, leads, or other components to the main body of the electronic component. The terminal position is important for ensuring proper connectivity and functionality of the component within a circuit. It is often specified in technical datasheets or component specifications to help designers and engineers understand how to properly integrate the component into their circuit designs.
END - Number of Functions1
- Supply Voltage
Supply voltage refers to the electrical potential difference provided to an electronic component or circuit. It is crucial for the proper operation of devices, as it powers their functions and determines performance characteristics. The supply voltage must be within specified limits to ensure reliability and prevent damage to components. Different electronic devices have specific supply voltage requirements, which can vary widely depending on their design and intended application.
3.3V - Base Part Number
The "Base Part Number" (BPN) in electronic components serves a similar purpose to the "Base Product Number." It refers to the primary identifier for a component that captures the essential characteristics shared by a group of similar components. The BPN provides a fundamental way to reference a family or series of components without specifying all the variations and specific details.
DS1990A - Pin Count
a count of all of the component leads (or pins)
2 - Power Supplies
an electronic circuit that converts the voltage of an alternating current (AC) into a direct current (DC) voltage.?
3/5V - Max Supply Voltage
In general, the absolute maximum common-mode voltage is VEE-0.3V and VCC+0.3V, but for products without a protection element at the VCC side, voltages up to the absolute maximum rated supply voltage (i.e. VEE+36V) can be supplied, regardless of supply voltage.
6V - Min Supply Voltage
The minimum supply voltage (V min ) is explored for sequential logic circuits by statistically simulating the impact of within-die process variations and gate-dielectric soft breakdown on data retention and hold time.
2.8V - Memory Size
The memory capacity is the amount of data a device can store at any given time in its memory.
8B - Organization
In the context of electronic components, the parameter "Organization" typically refers to the arrangement or structure of the internal components within a device or system. It can describe how various elements such as transistors, resistors, capacitors, and other components are physically arranged and interconnected on a circuit board or within a semiconductor chip.The organization of electronic components plays a crucial role in determining the functionality, performance, and efficiency of a device. It can impact factors such as signal propagation, power consumption, thermal management, and overall system complexity. Engineers carefully design the organization of components to optimize the operation of electronic devices and ensure reliable performance.Different types of electronic components may have specific organizational requirements based on the intended application and design considerations. For example, integrated circuits may have a highly compact and intricate organization to maximize functionality within a small footprint, while larger electronic systems may have a more modular and distributed organization to facilitate maintenance and scalability.
64X1 - Memory Density
Memory density in electronic components refers to the amount of data that can be stored in a given physical space or memory module. It is typically measured in bits or bytes per unit area, such as bits per square inch. Higher memory density means that more data can be stored in a smaller space, which is important for devices with limited physical size or power constraints. Memory density is a key factor in determining the capacity and performance of memory devices, such as RAM, ROM, and flash memory, and is a critical consideration in the design and manufacturing of electronic products.
64 bit - Access Time (Max)
Access Time (Max) is a parameter in electronic components, particularly in memory devices such as RAM (Random Access Memory) and storage devices like hard drives and SSDs (Solid State Drives). It refers to the maximum amount of time it takes for the component to retrieve data after receiving a request. In simpler terms, it measures the speed at which data can be accessed from the component. A lower access time indicates faster performance, as the component can quickly retrieve and deliver data to the system. Manufacturers often specify the maximum access time in the component's datasheet to help users understand its performance capabilities.
15000 ns - Parallel/Serial
The parameter "Parallel/Serial" in electronic components refers to the method of data transmission or communication within the component. In parallel communication, multiple bits of data are transmitted simultaneously over multiple channels or wires. This allows for faster data transfer rates but requires more physical connections and can be more susceptible to signal interference.On the other hand, in serial communication, data is transmitted sequentially over a single channel or wire. While serial communication may have slower data transfer rates compared to parallel communication, it is more cost-effective, requires fewer connections, and is less prone to signal interference.The choice between parallel and serial communication depends on the specific requirements of the electronic component and the overall system design, balancing factors such as speed, cost, complexity, and reliability.
SERIAL - Serial Bus Type
Serial bus type refers to the method by which data is transmitted between components in an electronic system using a serial communication protocol. It involves the sequential transfer of data bits over a single channel or wire, allowing for a reduced number of interconnections compared to parallel communication. Common examples of serial bus types include I2C, SPI, USB, and UART, each with its own specific protocol and applications. The choice of serial bus type can affect the speed, complexity, and power consumption of the communication between devices.
1-WIRE - Height6.45mm
- Length17.35mm
- Width17.35mm
- REACH SVHC
The parameter "REACH SVHC" in electronic components refers to the compliance with the Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) regulation regarding Substances of Very High Concern (SVHC). SVHCs are substances that may have serious effects on human health or the environment, and their use is regulated under REACH to ensure their safe handling and minimize their impact.Manufacturers of electronic components need to declare if their products contain any SVHCs above a certain threshold concentration and provide information on the safe use of these substances. This information allows customers to make informed decisions about the potential risks associated with using the components and take appropriate measures to mitigate any hazards.Ensuring compliance with REACH SVHC requirements is essential for electronics manufacturers to meet regulatory standards, protect human health and the environment, and maintain transparency in their supply chain. It also demonstrates a commitment to sustainability and responsible manufacturing practices in the electronics industry.
No SVHC - Radiation Hardening
Radiation hardening is the process of making electronic components and circuits resistant to damage or malfunction caused by high levels of ionizing radiation, especially for environments in outer space (especially beyond the low Earth orbit), around nuclear reactors and particle accelerators, or during nuclear accidents or nuclear warfare.
No - RoHS Status
RoHS means “Restriction of Certain Hazardous Substances” in the “Hazardous Substances Directive” in electrical and electronic equipment.
ROHS3 Compliant - Lead Free
Lead Free is a term used to describe electronic components that do not contain lead as part of their composition. Lead is a toxic material that can have harmful effects on human health and the environment, so the electronics industry has been moving towards lead-free components to reduce these risks. Lead-free components are typically made using alternative materials such as silver, copper, and tin. Manufacturers must comply with regulations such as the Restriction of Hazardous Substances (RoHS) directive to ensure that their products are lead-free and environmentally friendly.
Lead Free
Parts with Similar Specs
- ImagePart NumberManufacturerNumber of PinsMin Supply VoltageSupply VoltageMax Supply VoltageFactory Lead TimeNumber of TerminationsRoHS StatusView Compare
DS1990A-F5
2
2.8 V
3.3 V
6 V
6 Weeks
2
ROHS3 Compliant
2
2.8 V
5 V
6 V
6 Weeks
2
ROHS3 Compliant
2
2.8 V
5 V
6 V
6 Weeks
2
ROHS3 Compliant
DS1990A Feature
Operating Voltage: 2.8V to 6V
Communication protocol: 1-Wire
Identifier: 64-bit registration number (laser engraved)
Data Read time: 5ms
Sink current 20mA
One wire Pull-Up Voltage: 2.8V to 6V
Maximum Input low Voltage: 0.3V
Minimum Input high Voltage: 2.2V
DS1990A Application
Access Control
Work-In-Progress Tracking
Tool Management
Inventory Control
DS1990A Related Accessories
| Name | Usage |
| DS9490R | Connector to connect iButton with Laptop / Computer |
| DS9092 | iButton Probe to connect the iButton to other embedded circuits |
| DS9101 | Clip to store/carry the iButton |
| DS9096P | Holder to snap in iButton during travel or rugged usage. |
DS1990A Block Diagram
The block diagram below shows the major functional blocks of the device. The DS1990A takes the energy it needs to operate from the IO line, as indicated by the parasite power block. The ROM function control unit includes the 1-Wire interface and the logic to implement the ROM function commands, which access 64 bits of lasered ROM.

DS1990A Block Diagram
Where & How to use DS1990A
Where to use DS1990A?
The DS1990A is an Address only type iButton, which means you can only read the 64-bit unique identification and not write to it. This gadget has a 5ms read time and uses a one-wire communication protocol, so all the user has to do is touch the device to the reader. This makes it suitable for projects that require a specific action to be conducted after reading the value from the iButton, such as opening a valve or triggering a siren.
How to use DS1990A?
The DS1990A is not self-contained; it requires a probe/connector to connect it to a reader, such as a computer or embedded hardware. There are various methods to use a DS1990A; however, if you plan to use it with a computer, you won't have to worry about anything because Maxim has already given the necessary hardware and software. The DS1990A can be directly connected to the computer's USB port using the DS9490R connector, and the data from the iButton can be read using the Java application running on the computer. If you're interested in learning more, read Maxim's Quick Start Guide.
When using the module with an embedded application such as an ATmega (Arduino), PIC, or any other MCU/MPU, the situation is slightly different. To connect the iButton to the hardware, you'll need a probe like the DS9092L. Then you must program the hardware (MCU/MPU) to read the data from the iButton using the 1-Wire interface. The circuit for a typical application is given below.

How to use DS1990A
As you can see, communication only takes two wires, one of which is the ground wire. A 1K pull up resistor is used to pull the signal wire (IO Wire) high. Because the DS1990A can function between 2.8 and 6 volts, it can be used with both 3.3 and 5-volt microcontroller platforms.
DS1990A Package

DS1990A Package
DS1990A Manufacturer
In order to shorten the time to market and keep up with the development of the market, you need a complete integration from the chip to the supply chain. Maxim Integrated can provide you with integrated solutions in the industrial, medical, consumer, automotive, energy, computing and communications fields.
Datasheet PDF
- Application Notes :
- Other Related Documents :
- Datasheets :
- ConflictMineralStatement :
Popularity by Region
Why is DS1990A used easily by human operators?
Because its compact coin-shaped profile is self-aligning with mating receptacles, allowing the DS1990A to be used easily by human operators.
What advantage does a DS1990A have?
It is portable, durable, and the ultimate data carrier.
What is the alternative option for DS1990A?
The alternative option for DS1990A: DS1972, DS1982, DS1920, DS1991.
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