Dual nonvolatile convertor for precise adjustment

Edited by the Electronicstalk editorial team Dec 23, 2003

The SMP9220 is a dual 12bit nonvolatile DAC optimised for bias adjustment and calibration applications that demand high resolution and total accuracy.

The SMP9220 is a dual 12bit nonvolatile DAC optimised for bias adjustment and calibration applications that demand high resolution and total accuracy.

The SMP9220 contains two serial-data input, voltage-output, 4096-step convertors.

The product can operate over a wide supply range from 2.7 to 5.5V.

Internal precision buffers swing rail-to-rail with an input reference range from ground to the positive supply voltage.

The two 12bit DACs are supplemented with associated circuitry including an enhanced unity-gain output operational amplifier, highly accurate internal 1.25V reference, 12bit data latches, 12bit nonvolatile data registers, and an industry-standard-compatible I2C serial bus interface.

The nonvolatile feature of the SMP9220 allows the user to cycle power to the device without losing the DACs' setpoints.

A useful feature is available to place the DAC output, on power-up, in either a high impedance state or at ground if desired.

Both of the dual DACs give the user access to the ends of the potentiometer wipers, allowing any combination of voltages to be applied, thereby increasing flexibility and resolution in setting the output voltage.

The individual DACs can be ganged together, further enhancing their usefulness.

The SMP9220 is suitable for applications requiring high-accuracy and high-resolution settings such as laser bias and modulation current adjustment, power-supply trimming, voltage margining and precision potentiometer replacement.

The SMP9220 features the industry's highest known temperature stability of +/-15ppm/C.

A small temperature coefficient characteristic is imperative for setting either bias power or modulation control in a laser communication system, for example.

SMP9220 datasheets are available on the Summit website.

To speed user product development using the SMP9220 and Summit's other programmable products, Summit offers customers the SMX3200 programming system.

This is a complete development system that lets designers easily manipulate the characteristics of the product.

The SMX3200 design kit includes menu-driven Microsoft Windows graphical user interface (GUI) software to automate programming tasks - letting the user work at the applications level to speed their work, tailor the SMP9220 to their tasks, and automate/eliminate detailed programming.

The necessary hardware is included to interface the parallel port of a PC to the Summit evaluation card.

Once a user completes design and prototyping, the SMX3200 automatically generates a hexadecimal data file that can be sent to Summit for review and approval.

Summit then assigns a unique customer identification code to the file and programs the customer's production devices prior to production final electrical test.

This ensures that the devices will operation properly in the end application.

The design kit software can be downloaded today from Summit's website.

An evaluation card containing the SMP9220 dual 12bit DACPOT, support circuitry, and a port for "plug and play" programming via the available PC-compatible dongle connector and cable are available from Summit.

Available in volume quantities today, the SMP9220 is packaged in both 28-trace QFN and 48-lead surface-mount packages.

Commercial temperature range devices are priced at $4.15 and $4.25 for the two packages, respectively, in 10,000-unit quantities.