AD5170: 256-Position, Two-Tim

AD5170:  256-Position, Two-Time Programmable, I²C Compatible Digital Potentiometer

The AD5170 is a 256-position, two-time programmable, digital potentiometer1 that employs fuse link technology, giving users two opportunities to permanently program the resistance setting. For users who do not need to program the digital potentiometer setting in memory more than once, the OTP feature is a cost-effective alternative to EEMEM. The AD5170 performs the same electronic adjustment function as mechanical potentiometers or variable resistors with enhanced resolution, solid-state reliability, and superior low temperature coefficient performance.

The AD5170 is programmed using a 2-wire, I2C®-compatible digital interface. Unlimited adjustments are allowed before permanently setting the resistance value, and there are two opportunities for permanent programming. During OTP activation, a permanent blow fuse command freezes the wiper position (analogous to placing epoxy on a mechanical trimmer).

Unlike traditional OTP digital potentiometers, the AD5170 has a unique temporary OTP overwrite feature that allows for new adjustments even after the fuse is blown. However, the OTP setting is restored during subsequent power-up conditions. This feature allows users to treat these digital potentiometers as volatile potentiometers with a programmable preset.

For applications that program the AD5170 at the factory, Analog Devices, Inc., offers device programming software that runs on Windows NT®, Windows® 2000, and Windows XP operating systems. This software effectively replaces any external I2C controllers, thus enhancing the time-to-market of the systems of the user.

Applications

Systems calibration

Electronics level setting

Mechanical trimmers replacement in new designs

Permanent factory PCB settings

Transducer adjustment of pressure, temperature, position, chemical, and optical sensors

RF amplifier biasing

Automotive electronics adjustments

Gain control and offset adjustments

* The terms digital potentiometer, VR, and RDAC are used interchangeably.

 

Features

• 256-position digital potentiometer
• Two-time programmable (TTP) set-and-forget resistance setting allows second-chance permanent programming
• Unlimited adjustments prior to one-time programming (OTP) activation
• OTP overwrite allows dynamic adjustments with user-defined preset

• End-to-end resistance: 2.5 kΩ, 10 kΩ, 50 kΩ, 100 kΩ
• Compact 10-Lead MSOP (3 mm × 4.9 mm) package
• Fast settling time: tS = 5 μs typical in power-up
• See Data Sheet for Additional Information

Functional Block Diagram for AD5170