AFE5805 Datasheet, PDF (1/32 Pages) Texas Instruments – 8-CHANNEL ANALOG FRONT-END FOR ULTRASOUND

AFE5805
www.ti.com
SBOS421A – MARCH 2008 – REVISED MARCH 2008
8-CHANNEL ANALOG FRONT-END FOR ULTRASOUND
FEATURES
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•2 8-Channel Complete Analog Front-End:
– LNA, VCA, PGA, LPF, and ADC
• Ultra-Low Noise:
– 0.85nV/√Hz (TGC)
– 1.1nV/√Hz (CW)
• Low Power:
– 122mW/Channel (40MSPS)
• Low-Noise Pre-Amp (LNA):
– 20dB Fixed Gain
– 250mV_PP Linear Input Range
• Variable-Gain Amplifier:
– Gain Control Range: 46dB
• PGA Gain Settings: 20dB, 25dB, 27dB, 30dB
• Low-Pass Filter:
– Selectable BW: 10MHz, 15MHz
– 2nd-Order
• Gain Error: ±0.5dB
• Channel Matching: ±0.8dB
• Distortion, HD2: –45dBc at 0.2V_PP Input
• Clamping Control
• Fast Overload Recovery
• 12-Bit Analog-to-Digital Converter:
– 10MSPS to 50MSPS
– 69.5dB SNR at 10MHz
– 6dB Overload Recovery Within One Clock
Cycle
– Serial LVDS Interface
– Internal and External Reference
– Single-Ended or Differential Clock Input
• Integrated CW Switch Matrix
• 15mm × 9mm, 135-BGA Package:
– Pb-Free (RoHS-Compliant) and Green
APPLICATIONS
• Medical Imaging, Ultrasound
– Portable Systems
DESCRIPTION
The AFE5805 is a complete analog front-end device
specifically designed for ultrasound systems that
require low power and small size.
The AFE5805 consists of eight channels, including a
low-noise amplifier (LNA), voltage-controlled
attenuator (VCA), programmable gain amplifier
(PGA), low-pass filter (LPF), and a 12-bit
analog-to-digital converter (ADC) with low voltage
differential signaling (LVDS) data outputs.
The LNA gain is set for 20dB gain, and has excellent
noise and signal handling capabilities, including fast
overload recovery. VCA gain can vary over a 46dB
range with a 0V to 1.2V control voltage common to all
channels of the AFE5805.
The PGA can be programmed for gains of 20dB,
25dB, 27dB, and 30dB. The internal low-pass filter
can also be programmed to 10MHz or 15MHz.
The LVDS outputs of the ADC reduce the number of
interface lines to an ASIC or FPGA, thereby enabling
the high system integration densities desired for
portable systems. The ADC can either be operated
with internal or external references. The ADC also
features a signal-to-noise ratio (SNR) enhancement
mode that can be useful at high gains.
The AFE5805 is available in a 15mm × 9mm, 135-ball
BGA package that is Pb-free (RoHS-compliant) and
green. It is specified for operation from 0°C to +70°C.
SPI
8 Channels ^IN....1
IN8
Logic/Controls
Clamp
LNA
VCA/PGA
and
LPF
ADC
Reference
LVDS
OUT
CH_..1
CH8
CW Switch Matrix
I_OUT (10)
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PRODUCT PREVIEW information concerns products in the
formative or design phase of development. Characteristic data and
other specifications are design goals. Texas Instruments reserves
the right to change or discontinue these products without notice.
Copyright © 2008, Texas Instruments Incorporated