1 Features

• 8-Channel Complete Analog Front-End

– LNA, VCAT, PGA, LPF, ADC, and CW Mixer

• Programmable Gain Low-Noise Amplifier (LNA)

– 24, 18, 15 dB Gain

– 0.25, 0.5, 0.7 VPP Linear Input Range

– 0.63, 0.7, 0.9 nV/rtHz Input Referred Noise

– Programmable Active Termination

• 40 dB Low Noise Voltage Controlled Attenuator

(VCAT)

• 24/30 dB Programmable Gain Amplifier (PGA)

• 3rd Order Linear Phase Low-Pass Filter (LPF)

– 10, 15, 20, 30, 35, 50 MHz

• 14-bit Analog to Digital Converter w/ LVDS output

– 77 dBFS SNR at 65 MSPS

• Noise/Power Optimizations (Without Digital

Demodulator)

– 180 mW/CH at 0.75 nV/rtHz, 65 MSPS

– 109 mW/CH at 1.1 nV/rtHz, 40 MSPS

– 107 mW/CH at CW Mode

• Excellent Device-to-Device Gain Matching

– ±0.5 dB(typical) and ±1.1 dB(max)

• Programmable Digital I/Q Demodulator after ADC

– Wide Range Demodulation Frequency

– <1KHz Frequency Resolution

– Decimation Filter Factor M = 1 to 32

– 16xM tap FIR Decimation Filter

– LVDS Rate Reduction after Demodulation

– On-chip RAM with 32 preset Profiles

• Low Harmonic Distortion

• Low Frequency Sonar Signal Processing

• Fast and Consistent Overload Recovery

• Passive Mixer for Continuous Wave

Doppler(CWD)

– Low Close-in Phase Noise –156 dBc/Hz at 1

KHz off 2.5 MHz Carrier

– Phase Resolution of 1/16λ

– Support 16X, 8X, 4X and 1X CW Clocks

– 12dB Suppression on 3rd and 5th Harmonics

• Small Package: 15 mm x 9 mm, 135-BGA

• Operation Temperature: -40°C to 85°C

2 Applications

• Medical Ultrasound Imaging

• Nondestructive Evaluation Equipments

• Sonar applications

• Multichannel, High-Speed Data Acquisition

3 Description

The AFE5812 is a highly-integrated analog front-end

(AFE) solution specifically designed for ultrasound

systems in which high performance and small size are

required. The AFE5812 integrates a complete timegain-

control (TGC) imaging path and a CWD path.

It also enables users to select one of various power/

noise combinations to optimize system performance.

Therefore, the AFE5812 is a suitable ultrasound AFE

solution not only for high-end systems, but also for

portable ones.

The AFE5812 contains eight channels of voltage

controlled amplifier (VCA), 14-bit and 12-bit ADC, and

CW mixer. The VCA includes LNA, VCAT, PGA, and

LPF. The LNA gain is programmable to support 250

mVPP to 0.75 VPP input signals. Programmable active

termination is also supported by the LNA. The ultralow

noise VCAT provides an attenuation control range

of 40 dB and improves overall low-gain SNR, which

benefits harmonic imaging and near-field imaging.

The PGA provides gain options of 24 and 30 dB.

Before the ADC, a LPF can be configured as 10,

15, 20, 30, 35 or 50 MHz to support ultrasound

applications with different frequencies. In addition,

the signal chain of the AFE5812 can handle signal

frequency lower than 100 kHz, which enables the

AFE5812 to be used in both sonar and medical

applications. The high-performance 14-bit/65-MSPS

ADC in the AFE5812 achieves 77 dBFS SNR. It

ensures excellent SNR at low chain gain. The ADC’s

LVDS outputs enable flexible system integration

desired for miniaturized systems.

The AFE5812 integrates a low-power passive mixer

and a low-noise summing amplifier to accomplish

on-chip CWD beamformer. 16 selectable phasedelays

can be applied to each analog input signal.

Meanwhile, a unique third- and fifth-order harmonic

suppression filter is implemented to enhance CW

sensitivity.