max2078ctk Maxim Integrated Products, Inc., max2078ctk Datasheet - Page 8

• Manufacturer Part Number: max2078ctk
• Description: Octal-channel Ultrasound Front-end With Cw Doppler Mixers
• Manufacturer: Maxim Integrated Products, Inc.

Octal-Channel Ultrasound Front-End
with CW Doppler Mixers
AC ELECTRICAL CHARACTERISTICS—SERIAL PERIPHERAL INTERFACE
(DOUT loaded with 60pF and 10MΩ, 2ns rise and fall edges on CLK.)
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
Note 9:
Note 10: Channel-to-channel gain and phase matching measured on 30 pieces during engineering characterization at room tem-
Note 11: Voltage gain is measured by subtracting the output-voltage signal from the input-voltage signal. The output-voltage signal
Note 12: Mixer output-voltage compliance is the range of acceptable voltages allowed on the CW mixer outputs.
Note 13: Transconductance is defined as the quadrature-combined CW differential output current at baseband divided by the
8
Clock Speed
Mininimum Data-to-Clock Setup
Time
Mininimum Data-to-Clock Hold
Time
Mininimum Clock-to-CS Setup
Time
CS Positive Mininimum Pulse
Width
Mininimum Clock Pulse Width
Mininimum CS High to Mixer
Clock on
_______________________________________________________________________________________
Minimum and maximum limits at T
Noise performance of the device is dependent on the noise contribution from V
Note that the LVDS CWD LO clocks are DC-coupled. This is to ensure immediate synchronization when the clock is first
turned on. An AC-coupled LO is problematic in that the RC time constant associated with the coupling capacitors and the
input impedance of the pin causes a period of time (related to the RC time constant) when the DC level on the chip side of
the capacitor is outside the acceptable common-mode range and the LO swing does not excede both of the logic thresh-
olds required for proper operation. This problem associated with AC-coupling causes an inability to ensure synchronization
among beamforming channels. The LVDS signal is terminated differentially with an external 100Ω resistor on the board.
An external 100Ω resistor terminates the LVDS differential signal path.
Total on-chip power dissipation is calculated as P
x I
This response time does not include the CW output highpass filter. When switching to VGA mode, the CW outputs stop
drawing current and the output voltage goes to the rail. If a highpass filter is used, the recovery time may be excessive
and a switching network is recommended, as shown in the Applications Information section.
See the Ultrasound-Specific IMD3 Specification section.
The reference input noise is given for 8 channels, knowing that the reference-noise contributions are correlated in all 8
channels. If more channels are used, the reference noise must be reduced to get the best noise performance.
perature. Each mixer is used as a phase detector and produces a DC voltage in the IQ plane. The phase is given by the
angle of the vector drawn on that plane. Multiple channels from multiple parts are compared to each other to produce the
phase variation.
is obtained by taking the differential CW I output and summing it in quadrature with the differential CW Q output. The input
voltage is defined as the differential voltage applied to the CW input pins.
mixer’s input voltage.
PARAMETER
11V
.
SYMBOL
t
MIXCS
t
t
t
t
t
CW
CH
EW
CS
ES
A
= +25°C and +70°C are guaranteed by design, characterization, and/or production test.
DISS
CONDITIONS
= V
CC
1 x I
CC
1 + V
CC
2 x I
REF
CC
. Use a low-noise supply for V
2 + V
MIN
REF
x I
REF
TYP
5
0
5
1
2
2
+ [11V - (I
MAX
10
11V
REF
/4) x 162]
UNITS
MHz
.
ns
ns
ns
ns
ns
ns