AFE5812 datasheet(39/109 Pages) TI

Part #	AFE5812

Description	AFE5812 Fully Integrated, 8-Channel Ultrasound Analog Front End with Passive CW Mixer, and Digital I/Q Demodulator, 0.75 nV/rtHz, 14/12-Bit, 65 MSPS, 180 mW/CH

PDF	109 Pages

Scroll/Zoom	100%

Manufacturer	TI [Texas Instruments]

Direct Link	http://www.ti.com

Logo

39 / 109 page

LNA1

Weight

LNA2~8

In-phase

CLK

Quadrature

CLK

I/V

Summed

In-Phase

Summed

Quadrature

Syncronized I/Q

CLOCKs

AFE5812

www.ti.com

SLOS816A – MARCH 2015 – REVISED MARCH 2015

Figure 73. Block Diagram of 1 x ƒcw mode

10.3.6 Digital I/Q Demodulator

AFE5812 also includes a digital in-phase and quadrature (I/Q) demodulator and a low-pass decimation filter. The

main purpose of the demodulation block is to reduce the LVDS data rate and improve overall system power

efficiency. The I/Q demodulator accepts ADC output with up to 65 MSPS sampling rate and 14-bit resolution. For

example, after digital demodulation and 4× decimation filtering, the data rate for either in-phase or quadrature

output is reduced to 16.25 MSPS, and the data resolution is improved to 16 bits consequently. Hence, the overall

LVDS trace reduction can be a factor of 2. This demodulator can be bypassed and powered down completely if it

is not needed.

The digital demodulator block given in AFE5812 is designed to do down-conversion followed by decimation. The

top-level block is divided into two exactly similar blocks: (1) subchip0 and (2) subchip1. Both subchips share four

channels each, that is, subchip0 (ADC.1, ADC.2, ADC.3, and ADC.4) and subchip1 (ADC.5, ADC.6, ADC.7, and

ADC.8).

Submit Documentation Feedback

Product Folder Links: AFE5812

AFE5812 Datasheet(PDF) 39 Page - Texas Instruments