TI rolls fastest 12-bit ADC

By Gina Roos, editor-in-chief

Texas Instruments (TI) rolled out a new ultra-high-speed analog-to-digital converter (ADC), claiming the industry’s widest-bandwidth, fastest-sampling-rate, and lowest-power-consumption ADC. The ADC12DJ5200RF ADC , with 8-GHz bandwidth and 10.4-gigasamples-per-second (GSPS) sampling, covers the widest frequency spectrum for 5G testing, oscilloscopes, mass spectrometry, and direct X-band sampling radar applications, helping engineers achieve high measurement accuracy in these applications.

The ADC12DJ5200RF ADC  offers a buffered analog input and integrated digital down-converter with programmable NCO and decimation settings, and it features a JESD204B/C interface. The ADC12DJ5200RF claims the first standalone GSPS ADC to support the JESD204C standard interface, helping to reduce the number of serializer/deserializer lanes needed to output data to FPGAs.

Wideband applications such as radar, millimeter-wave and microwave-frequency backhaul types of communications systems, and testing of 5G systems are driving the need for this type of solution, said Philip Pratt, business development for aerospace & defense, high-speed converters, TI.

“At this high sampling rate, you want to take advantage of it in medium- to high-bandwidth systems, where it also shrinks the footprint quite a bit,” he said. “It’s best for wideband signal collection across those applications such as test, defense, and radar.”

The new ADC, at 8 GHz, delivers as much as 20% higher analog input bandwidth than competitive devices at 20% less power consumption, which allows engineers to directly digitize very high frequencies without the power consumption, cost, and size of additional down-conversion.

With direct RF sampling up to 10 GHz, the ADC extends into the X-band. The direct RF sampling capability at frequencies above 8 GHz removes the RF down-conversion stages, which saves board space and decreases component count, said Pratt.

“Integrating the digital down-converter — the DDC — provides the frequency conversion in the chip,” he said. “It also reduces the amount of data that has to come off the chip and the number of SerDes connections to the FPGA.”

In dual-channel mode, the ADC12DJ5200RF samples at 5.2 GSPS and captures instantaneous bandwidth (IBW) as high as 2.6 GHz at 12-bit resolution. In single-channel mode, the ADC samples at 10.4 GSPS and captures IBW up to 5.2 GHz. The precursor to the ADC12DJ5200RF offered 6.4 GSPS (3.2 GSPS in dual-channel mode/6.4 GSPS in single-channel mode), so this is a significant increase in sampling rate.

What makes it attractive to customers is the combination of benefits, including wideband signal collection, integrated DDC, low phase noise, and the ability to connect to the FPGA in as few lines as possible, said Pratt. “It’s a balancing act between performance, size, bandwidth, and the interface itself.”

Other key features include high signal detection performance, high measurement accuracy (offset error as low as ±300 µV and zero temperature drift), and extremely low code error rate (CER), which is more than 100 times better than competing devices, according to TI.

Here are the specs:

• Configurations: Single 12-bit 10.4 GSPS, Dual 12-bit 5.2 GSPS
• Power: 4.1 W total
• Buffered Input: −3-dB bandwidth of 8 GHz, 800 mVpp
• Noise Floor (10.4 GSPS): −154 dBFS/Hz (55.1 dBFS SNR)
• IMD3 (4.2 GHz): −77dBc (@ −9 dBFS)
• Code Error Rate: 10−18
• Optional Decimation with NCO: 4× or 8× complex decimation
• Digital Interface: JESD204B/C (up to 16 Lanes, up to 17.1 Gbps)
• Power supplies: 1.1 V, 1.9 V
• Package: 10 × 10 mm, BGA, 0.8-mm pitch

The ADC12DJ5200RF is pin-compatible with other TI GSPS ADCs (ADC12DJ3200, ADC12DJ2700, and ADC08DJ3200) for an easier upgrade path from 2.7 GSPS to 10.4 GSPS. The ADC12DJ5200RF  dual- and single-channel ADC, packaged in a 144-ball, 10 × 10-mm flip-chip ball grid array (FCBGA), is available for sampling through the TI store.

Two plug-and-play evaluation modules — ADC12DJ5200RFEVM  and TSW14J57EVM  — are available from the TI store and authorized distributors. TI will demonstrate the ADC12DJ5200RF in Booth No. 1272 at the International Microwave Symposium (IMS) in Boston, June 4−6, 2019.