|
技术交流 | 电路欣赏 | 工控天地 | 数字广电 | 通信技术 | 电源技术 | 测控之家 | EMC技术 | ARM技术 | EDA技术 | PCB技术 | 嵌入式系统 驱动编程 | 集成电路 | 器件替换 | 模拟技术 | 新手园地 | 单 片 机 | DSP技术 | MCU技术 | IC 设计 | IC 产业 | CAN-bus/DeviceNe |
ADI数字修调技术:DigiTrim Technology |
作者:iC921 栏目:模拟技术 |
DigiTrimTM TECHNOLOGY Frequently Asked Questions1. Why should I be concerned about trimming? 2. As consumers continue to PUSH for lower prices and higher performance, SYSTEM suppliers must find new ways to contain costs while maintaining or even improving accuracy. The task becomes more difficult as supply voltages continue shrinking, magnifying the effect of error sources. Many SYSTEMs use manual or electronic calibration to eliminate offsets. This is effective, but consumes additional labor and EQUIPMENT. 3. Controlling offsets at the component level reduces or eliminates the requirements for SYSTEM calibration. Various trimming methods are used to minimize offset and increase PRECISION in AMPLIFIERs. DigiTrim makes really low-cost trimming possible, enabling the production of PRECISION components for high-volume, price-sensitive applications. 4. Will the AD860x be the ONLY family ANALOG Devices offers with this TECHNOLOGY? 5. No. ANALOG Devices will apply DigiTrim to future high-PRECISION, high-volume op amp families, as well. 6. What high-volume applications would benefit from DigiTrim accuracy? 7. PCs; COMPUTER peripherals, including PCMCIA modems; communications; automotive sensor conditioning; IR receivers; medical and other instrumentation; and bar code scanners to NAME a few. 8. What's so important about DigiTrim? There are lots of other trim methods. 9. The most important reason is cost. Other trim methods require extra DEVICE pins, special PROCESSing and/or lots of extra die area. The DigiTrim method doesn't require any extra pins. It uses STANDARD PROCESSes, and the amount of die area required is fairly small. Also, this die area will scale with the PROCESS. So, as we migrate to finer geometry PROCESSes at lower voltages, the trim CIRCUITry will become smaller like the rest of the CIRCUIT. 10. The trimming is performed in-package. This allows us to compensate for assembly effects - increasing our final accuracy. It also costs less to trim at the packaged DEVICE level rather than at the wafer level, where most other trim methods are performed. 11. Finally, no additional EQUIPMENT is needed for this trim. This helps KEEP costs low. It also improves our ability to respond to new production demand, since we don't have to wait for trim EQUIPMENT delivery to increase capacity. Our competitors either SELECT higher grades from their overall population of production PARTs (NATIONAL SEMICONDUCTOR's and Texas Instruments' "A" grades of CMOS AMPLIFIERs like LMC6482A and TLV2462A) or use expensive thin film trimming to reduce offsets (Burr-Brown's OPA340 AMPLIFIERs). Neither of these approaches represents a reliable and cost-effective method for producing PRECISION AMPLIFIERs in really high volumes. 12. Can the user trim the PARTs? 13. That won't be possible with first generation DigiTrim PARTs. Since the offset adjustment affects the common-mode voltage performance, these PARTs will be factory trimmed ONLY. Also, the trimming range designed for these AMPLIFIERs isn't sufficient to compensate for the level of error voltages commONLY found at the SYSTEM level. We are investigating a different AMPLIFIER design that could allow user trimming of SYSTEM offsets. 14. Is it possible to reprogram the adjustment? 15. Once the FUSEs are blown their adjustment is permanent. We've also included a lockout, so no further PROGRAMMING is possible once the trimming is completed. However, we are able to simulate the trimmed condition of the PARTs before the FUSEs are blown. This allows us to achieve the optimal adjustment for each PART. 16. Are there any reliability issues? 17. No. The polysilicon FUSE technique is very reliable and fail-safes are built into the PARTs to prevent any accidental adjustments by our customers. 18. Why aren't additional pins required? 19. We are able to enter the DIGITAL trimming information through some of the ANALOG pins by using a unique DIGITAL "key" signal. Once the lockout is complete, the DIGITAL section is disconnected from these ANALOG pins. 20. How do you know what VALUE to trim? 21. We can simulate the effect of the trims on the actual CIRCUIT. We measure the initial offset, calculate the desired trim and then simulate the trim. We re-measure the offset and we can re-simulate a MODIFIED trim to achieve a better result. Once we have our optimum simulated VALUE, we actually perform the trim and the lockout. * - 本贴最后修改时间:2005-5-21 23:54:08 修改者:iC921 |
2楼: | >>参与讨论 | |||||||||||||||||||||||||||||
作者: iC921 于 2005/5/22 0:04:00 发布:
The DigiTrim Family of Products Selection Table: The DigiTrimTM Family of Products By eliminating CIRCUIT trims, the DigiTrim TECHNOLOGY allows designers to save on overall SYSTEM cost...
|