Product Flyer June 2000 MB86060 Version 1.2 16-Bit Interpolating Digital to Analog Converter The Fujitsu MB86060 is a high performance 12-bit, 400MSa/s Digital to Analog Converter (DAC) enhanced with a 16-bit interpolation filtering front-end. Use of novel techniques for the converter architecture delivers high speed operation consistent with BiCMOS or bipolar devices but at the low power of CMOS. Fujitsu’s proprietary architecture is the subject of several patent applications. Additional versatility is provided by selectable input interpolation filters, programmable dither and noise shaping facilities. Excellent SFDR performance coupled with high speed conversion rate and low power make this device particularly suitable for high performance communication systems, in particular direct IF synthesis applications. FME/MS/SFDAC1/FL_1/4270 PLASTIC PACKAGE LQFP-80 Features (FPT-80P-M05) • 16-bit Interpolating Digital to Analog conversion • x1, x2 or x4 interpolation filtering • 100MSa/s input, with x4 interpolation enabled • Programmable highpass filtered dither • Selectable 2nd order noise shaping Ordering Information • Versatile CMOS digital interface • Internal programmable clock multiplier Part Order Number • Performance enhanced pinout with on-chip decoupling MB86060 Datasheet Contact Sales • 0.35µm CMOS technology with Triple Well MB86060 DAC MB86060PFV MB86060 Development Kit DK86060-3 MB86060 Development Kit User Manual Contact Sales • Low power, 3.3V operation (343mW @32MSa/s input, x4) • Industrial temperature range (-40°C to +85°C) Applications • Direct IF Synthesis • Cellular basestations • Wide-band communications systems This product has Patents applied for in the US and elsewhere including GB2333191A, EP0935345A, JP11-274934A, GB2333171A, EP0930717A, JP11-274935A, GB2333190A, EP0929158A, JP11-243339A, GB2335097A, EP0940923A, JP11-317667A, GB2335076A, EP0940852A, JP11-251530A. Copyright © 2000 Fujitsu Microelectronics Europe GmbH Page 1 of 6 June 2000 Version 1.2 FME/MS/SFDAC1/FL_1/4270 MB86060 16-Bit Interpolating Digital to Analog Converter Functional Description The MB86060 integrates a 12-bit 400MSa/s DAC with selectable front end processing to provide input interpolation filtering, dither and noise shaping. Versatile interfacing via the 16-bit parallel CMOS data input allows different system requirements to be accommodated, with either offset binary or 2’s complement data formats selected by an input format control. The device is manufactured in a 0.35µm advanced CMOS process with Triple Well extension giving improved isolation between analog blocks and digital-analog. g Clk Select CLK in (diff.) Crystal Clock Multiplier 2 Lock Mult mode Delay line ctrl HP Filter Data CLK out (diff.) Data In Dither Generator 3 2 Programmable Dithermay be excluded from final MP devices Clock Divider [x2 slow] 16 x2 3 [x2 fast] 16 x2 Noise Shaper Data Format Filter control Dither NS Enable Over 12 2 Bandgap Reference DAC Output DAC 2 Reset FML Mixed Signal Shuffle Control MB86060 Functional Block Diagram Converter Architecture The MB86060 Interpolating DAC incorporates a number of novel design aspects that are subject to patent applications. Key to its operation are the current sources where segmented, common centroid, interleaved techniques for the most significant bits, as well as load matching ensure good linearity and low distortion to at least the 12-bit level. In the switch elements tracking capacitance is minimised to improve settling, while controlled rise and fall times improve SFDR performance. Finally the digital decoding uses a 3dimensional addressing approach to minimise propagation delays from latch to element. Page 2 of 6 Copyright © 2000 Fujitsu Microelectronics Europe GmbH June 2000 Version 1.2 FME/MS/SFDAC1/FL_1/4270 MB86060 16-Bit Interpolating Digital to Analog Converter Segment Shuffling (dBc) SFDR The DAC core incorporates a proprietary segment shuffling capability which is provided to further improve linearity, and hence improve SFDR. This feature reduces any signal level dependent effects on linearity as the same code can be generated by the same number of MSB cells but taken from any quarter of the MSB segments. Segment shuffling can be selected to operate every 4, 8 or 16 updates of the DAC output using a random shuffle sequence between the four segments. Most performance improvement will be observed when the device is used in one of the interpolating modes. The effect of segment shuffling is to produce a spread noise spectrum, raising the overall noise 95 floor, but reducing the distortion. For minimum distortion when generating low frequency 50MSa/s Input Data Rate 90 x4 Mode, 200MSa/s DAC Rate signals, it is recommended that the shuffling Noise Shaper On, Dither Off Shuffle On clock rate is no more than 25MHz (DAC Rate / Amplitude = -1dBFS 85 Segment Shuffling setting). However, low 80 shuffle clock rates give reduced spreading out of distortion components. Shuffle Off Noise Shaping Second order noise shaping can be applied to interpolated data prior to being passed to the DAC core. When enabled this provides an additional reduction in quantisation noise to that gained through the use of interpolation filtering. For the x4 interpolation mode this improvement will be 16dB, equivalent to 2.7 bits. 75 70 65 60 0 10 20 30 40 Generated Frequency (MHz) Single Tone SFDR Performance Clock The MB86060 incorporates a clock multiplier to generate the required internal x1, x2 and x4 clock signals from an external reference. The clock multiplier is based on a delay-lock-loop whose delay is adjusted by a charge pump controlled by a phase detector. A ‘Lock’ indicator is provided so that the system can monitor the multiplier’s condition. For systems where a high frequency clock is available, or the lowest possible jitter is required, then the clock multiplier may be disabled and the external clock used directly. Interpolating Filters The integration of interpolating filters provides a number of benefits to the system implementation. In general, improved performance can be gained by using a higher DAC conversion rate effectively providing a higher level of oversampling from the generated signal. For the designer, the problem with this approach is generating the required high speed digital data, especially when considering high performance wideband designs with up to 50MHz of signal. Integrating this processing on-chip with the DAC alleviates this problem. Copyright © 2000 Fujitsu Microelectronics Europe GmbH Page 3 of 6 June 2000 Version 1.2 FME/MS/SFDAC1/FL_1/4270 MB86060 16-Bit Interpolating Digital to Analog Converter Other benefits include a reduced effect due to the sinx/x roll-off due to the DAC sample and hold output stage, which for a conventional DAC represents -4dB at Nyquist, compared to only -0.22dB when operating in the x4 interpolating mode. Also the digital interpolation filters sharp cutoff and effective stop-band attentuation improves both in and out-of-band SFDR. This is illustrated below. -4dB Sinx x -13dB x1 mode 0 100 FDAT & FDAC 200 Filter Pass Band = 0.43.FDAT (-0.1dB) 300 400 500 MHz 400 500 MHz 400 FDAC 500 MHz 400 FDAC 500 MHz Sinx x -0.9dB X2 (slow) mode -18dB -13dB 0 100 FDAT 200 FDAC Filter Pass Band = 0.37.FDAT (-0.1dB) X2 (fast) mode Sinx x -0.9dB 0 100 300 200 FDAT 300 Filter Pass Band = 0.43.FDAT (-0.1dB) x4 mode Sinx x -0.22dB 0 100 FDAT 200 300 The MB86060 features four interpolation filter modes x1, x2(slow), x2(fast) and x4. Mode x1 is as per a conventional DAC, and choosing between the remaining three modes would depend on the system requirements. Mode x2(slow) may be advantageous to a system requiring the benefits of interpolation filtering but saving some power by not running the DAC core at full rate. Mode x2(fast) gives access to the wider band, slower roll-off interpolation filter allowing wider band signals to be generated compared to the other modes, for example 74MHz (-0.1dB) for 200MSa/s data rate. Mode x4 for the complete interpolation filter operation. Page 4 of 6 Copyright © 2000 Fujitsu Microelectronics Europe GmbH June 2000 Version 1.2 FME/MS/SFDAC1/FL_1/4270 MB86060 16-Bit Interpolating Digital to Analog Converter Interpolation Filter Response 20 0 Pass Band 0.43fs (-0.1dB) Stop Band -75dBFS from 0.59Fs (Excluding transition band image around 1.5Fs) -20 -40 [Frequency axis normalised to input data rate] dB -60 [Simulated overall x 4 Interpolation filter response] -80 -100 Combined Filter Characteristics -120 0 0.2 0.4 0.6 0.8 1.0 1.2 Frequency 1.4 1.6 1.8 2.0 Programmable Dither Dither can be added to improve low-level performance and reduce effects due to nonlinearities within the DAC, and reducing DNL and glitch energy. The dither has programmable amplitude, and is high pass filtered to fall out of the pass band. For dither to be used effectively both amplitude and frequency characteristics must be carefully considered. Obviously the dither amplitude should be larger than the nonlinearities to be masked, but levels significantly larger than this will ultimately limit available dynamic range for the wanted signal. Similar considerations should be made for the frequency characteristics, which in the MB86060 the dither is highpass filtered such that the majority of the energy is concentrated at Nyquist of the DAC output rate. Development Kit A development kit, reference DK86060, is available for the MB86060 16-bit Interpolating DAC. The kit includes an evaluation board that enables simple and effective evaluation of the device. The board provides a complete evaluation environment for the DAC. A transformer coupled differential output interface is provided to simplify integration into target applications and development environments. An RF clock source can be connected via the transformer coupled input, and 16-bit data via a 40-way IDC header. The development kit includes, • Evaluation board with MB86060 device fitted • Spare MB86060 for customer development • User Manual Copyright © 2000 Fujitsu Microelectronics Europe GmbH Page 5 of 6 June 2000 Version 1.2 FME/MS/SFDAC1/FL_1/4270 MB86060 16-Bit Interpolating Digital to Analog Converter Worldwide Headquarters Japan Fujitsu Limited Asia Fujitsu Microelectronics Asia Pte Limited Tel: +81 44 754 3753 Fax: +81 44 754 3329 1015 Kamikodanaka 4-1-1 Nakahara-ku Kawasaki-shi Kanagawa-ken 211-88 Japan Tel: Fax: 151 Lorong Chuan #05-08 New Tech Park Singapore 556741 http://www.fujitsu.co.jp/ +65 281 0770 +65 281 0220 http://www.fmap.com.sg/ USA Fujitsu Microelectronics Inc Europe Fujitsu Microlectronics Europe GmbH Tel: +1 408 922 9000 Fax: +1 408 922 9179 3545 North First Street San Jose CA 95134-1804 USA Tel: +49 6103 6900 Fax: +49 6103 690122 Am Siebenstein 6-10 D-63303 Dreieich-Buchschlag Germany Tel: +1 800 866 8608 Fax: +1 408 922 9179 Customer Response Center Mon-Fri: 7am-5pm (PST) http://www.fujitsu-fme.com/ http://www.fujitsumicro.com/ The contents of this document are subject to change without notice. Customers are advised to consult with FUJITSU sales representatives before ordering. The information and circuit diagrams in this document presented as examples of semiconductor device applications, and are not intended to be incorporated in devices for actual use. Also, FUJITSU is unable to assume responsibility for infringement of any patent rights or other rights of third parties arising from the use of this information or circuit diagrams. FUJITSU semiconductor devices are intended for use in standard applications (computers, office automation and other office equipment, industrial, communications, and measurement equipment, personal or household devices, etc.). CAUTION: Customers considering the use of our products in special applications where failure or abnormal operation may directly affect human lives or cause physical injury or property damage, or where extremely high levels of reliability are demanded (such as aerospace systems, atomic energy controls, sea floor repeaters, vehicle operating controls, medical devices for life support, etc.) are requested to consult with FUJITSU sales representatives before such use. The company will not be responsible for damages arising from such use without prior approval. Any semiconductor devices have inherently a certain rate of failure. You must protect against injury, damage or loss from such failures by incorporating safety design measures into your facility and equipment such as redundancy, fire protection, and prevention of overcurrent levels and other abnormal operating conditions. If any products described in this document represent goods or technologies subject to certain restrictions on export under the Foreign Exchange and Foreign Trade Control Law of Japan, the prior authorization by Japanese government should be required for export of those products from Japan. FME/MS/SFDAC1/FL_1/4270 - 1.2 Page 6 of 6 Copyright © 2000 Fujitsu Microelectronics Europe GmbH