Contents | General | MB86060 16-bit 100MSa/s Interpolating DAC | MB86061 12-bit 400MSa/s (ECL i/p) DAC | Application Questions | Glossary |
MB86061 12-bit 400MSa/s (ECL i/p) DAC
3.1: What is MB86061 used for?
MB86061 provides designers with direct access to the high performance 12-bit DAC core used in MB86060. This device will be suited to test and instrumentation applications where higher generated frequencies may be required and dedicated pre-processing can be provided.
3.2: Is it a 3V part?
MB86061 is a CMOS device and as such should be powered from a standard 3.3V ±10% supply. Additionally, in order to power the ECL input interface, a -2V supply is also required. Because the internal design of the device does not use any conventional ECL technology current consumption on this rail is only in the order of 15mA.
3.3: Why does MB86061 have an 'ECL' Interface?
The first point to note is that the device is manufactured in CMOS but features a true ECL compatible data interface. This should be differentiated from pseudo ECL [PECL] which are low signal swing but operate above 0V. A traditional CMOS interface could not have been used since the input data rate would have been limited to approximately 200MHz. Adopting a 'standard' ECL interface also provides existing designs with a low risk upgrade path. There already exists a range of competitive products using ECL data inputs but typically these are 8-10 bit, 250-300MSa/s parts over which significant performance improvements can be achieved by switching to the MB86061.
Apart from the more obvious issue of a simple upgrade path for existing designs there are two fundamental advantages of providing the ECL interface. Firstly a data generating device capable of providing 400MSa/s data will (typically) be ECL, and secondly attempting to circumnavigate this limitation by providing multiple CMOS sources e.g. 4 direct digital synthesis devices, will require 400MSa/s multiplexers to combine the data sources which will also be ECL.
3.4: Can I use MB86061 to replace an existing 10-bit DAC?
Yes, MB86061 can be used to replace lower resolution devices in existing designs. Some performance improvements may still be obtained due to the superior analog output stage, but significantly savings may be made in power consumption and price compared to Bipolar or BiCMOS devices. Unused data inputs should be pulled down to the -2V supply via 50OHM resistors.
