Imec and Renesas Electronics claim record ADC for next-generation high-bandwidth wireless receivers
February 23, 2012 // Paul Buckley
At International Solid-State Circuit Conference (ISSCC2012) imec and Renesas Electronics Corporation are reporting an innovative SAR ADC with a marked improvement in power efficiency and speed, targeting wireless receivers for next-generation high-bandwidth standards such as LTE-advanced and the emerging generation of Wi-Fi (IEEE802.11ac). The world-first 11bit 250 MSamples/s SAR ADC achieves a record low-power consumption of 1.7 mWatt.
SAR ADCs provide high power efficiencies as well as a small form factor, making this architecture attractive for a wide variety of wireless applications. SAR ADCs are frequently the preferred architecture for applications with moderate resolution and sampling frequencies. However, wireless receivers for next-generation high bandwidth standards such as LTE-advanced and the new generations of Wi-Fi require much faster ADCs.
The new SAR ADC architecture, developed by imec and Renesas Electronics, is an answer to the need for much faster low-power ADCs with small form factor. The reported ADC is an ultra-low power (1.7 mWatt) high resolution (11b) fully-dynamic, two-step interleaved pipelined SAR ADC achieving a record power efficiency of 10fJoule per conversion step at a sampling speed as high as 250MSamples/s. This is a spectacular increase of the speed and sampling frequency, which are both an order of magnitude better than state-of-the art available ADC IP blocks.
The result is obtained with a new converter architecture based on prior groundbreaking ADC designs from imec, exploiting the opportunities of modern advanced CMOS technologies. The design uses completely dynamic circuits, such that the power consumption scales linearly with the sampling frequency, and is implemented with a maximum amount of digital content, leaving the comparator as the only analog building block.
The ADC prototype has been manufactured in 40 nm CMOS with a core chip area of 0.066 mm2. Measurements show a DNL and INL of respectively 0.8/-0.5 and 1.1/-1.5 LSB. The dynamic performance is characterized by 62 dB SNDR (10.0 ENOB) at 10 MSamples/s, which is maintained up to 9.5 ENOB level for a sampling speed of up to 250 MSamples/s. The power consumption is 6.9pJoule per conversion (70 µWatt at 10 MSamples/s, 1.7 mWatt at 250 MSamples/s), resulting in a spectacular energy efficiency of 7 to 10fJoule per conversion-step.
Also at ISSCC, imec and Renesas Electronics is presenting a new way to connect the ADC architecture with the complete radio architecture. To improve the power efficiency of the total receiver system, and avoid issues related to large input capacitors in a voltage-domain ADC system, a 3.2-51.2 mSiemens current domain variable-gain transconductor (VGA) was used to drive a charge-domain SAR ADC with no overhead, and as such minimize the overall system power consumption. A 10b 10-80 MSamples/s VGA-ADC prototype in 40 nm CMOS achieves 70 dB DR while consuming less than 5.45 mA from a 1.1 V supply.
Visit Renesas Electronics at www.renesas.com
Visit imec at www.imec.be
Automotive MCU benchmark takes energy efficiency into account
May 21, 2013
Today, cars are crammed with microprocessors, and many of them are not completely switched off when the driver parks and ...
EnSilica partners Cross Border Technologies to boost sales growth in key European markets
Industry's first ultra-wideband Doherty amplifiers support broadband operation
Graphics chip recognizes nearby pedestrians and bicycles
EMS boom for medical industry says analyst
Gemalto teams with Encore Networks for mission critical M2M communications as US shifts to wireless
May 21, 2013
European smartcard specialist Gemalto has teamed up with US machine-to-machine (M2M) router supplier Encore Networks to provide ...
Solar industry capital spending hits seven-year low in 2013 but upturn is on the cards
Apple's overseas tax evasion stirs debate over US tax code
Could Intel enable USD200 Ultrabook?
InterviewWireless control drives Atmel in Europe
Atmel's recent acquisition of Osmo Devices with a WiFi Direct design center in Cambridge and some key microcontroller launches has seen the company focus heavily on wireless control in Europe says Jörg ...
Filter WizardCheck out the Filter Wizard Series of articles by Filter Guru Kendall Castor-Perry which provide invaluable practical Analog Design guidelines.
Linear video channel
READER OFFERRead more
The development platform for i.MX 6Quad from element14 (built to the Freescale SABRE Lite design) is an evaluation platform featuring the powerful i.MX 6Q, a multimedia application processor with Quad ARM Cortex-A9 cores at 1.2 GHz from Freescale Semiconductor.
This month, Freescale and element14 are giving away five such platforms, worth £128.06 each, for EETimes Europe's readers to win. The platform helps evaluate the rich set of peripherals and includes a 10/100/Gb Ethernet port, SATA-II, HDMI v1.4, LVDS, parallel RGB interface, touch screen interface, analog headphone/microphone, micro TF and SD card interface, USB, serial port, JTAG, camera interface, and input keys for Android.
And the winners are...
In our previous reader offer, Pico Technology was giving away one of its recently launched PicoScope 3207B, a 2-channel USB 3.0 oscilloscope worth 1451 Euros. Lucky winner Mr L. Sanchez-Gonzalez from Spain should be receiving his PicoScope 3207B soon. Let's wish them some interesting findings with his projects.
December 15, 2011 | Texas instruments | 222901974
Unique Ser/Des technology supports encrypted video and audio content with full duplex bi-directional control channel over a single wire interface.