Datasheet

MAX2078
Octal-Channel Ultrasound Front-End
with CW Doppler Mixers
______________________________________________________________________________________ 11
LARGE-SIGNAL BANDWIDTH
vs. FREQUENCY
MAX2078 toc16
FREQUENCY (MHz)
GAIN (dB)
10
-10
0
10
20
30
-20
1 100
V
OUT
= 1V
P-P
GAIN = 20dB
18MHz
15MHz
10MHz
9MHz
COMMON-MODE OUTPUT VOLTAGE
vs. GAIN
MAX2078 toc17
GAIN (dB)
COMMON-MODE OUTPUT VOLTAGE (V)
352617
1.6
1.7
1.8
1.9
1.5
8
44
DIFFERENTIAL OUTPUT IMPEDANCE
vs. FREQUENCY
FREQUENCY (MHz)
REAL COMPONENT (Ω)
IMAGINARY COMPONENT (Ω)
40302010
60
120
180
60
40
20
0
80
0
050
MAX2078 toc18
REAL
IMAGINARY
______________________________________________________________________________________ 11
Typical Operating Characteristics (continued)
( Typical Application Circuit , V
REF
= 2.475V to 2.525V, V
CC1
= 3.13V to 3.47V, V
CC2
= 4.5V to 5.25V, T
A
= 0°C to +70°C, V
GND
= 0V,
NP = 0, PD = 0, CLP = 0, D43/D42/D41/D40 = 1/0/1/0 (R
IN
= 200Ω, LNA gain = 18.5dB), D45/D44 = 1/1 (f
C
= 18MHz), f
RF
= f
LO
/16
= 5MHz, capacitance to GND at each of the VGA differential outputs is 25pF, differential capacitance across VGA outputs is 15pF,
R
L
= 1kΩ differential, R
S
= 200Ω, CI_, CQ_ pulled up to 11V through four separate 0.1% 162Ω resistors, the rise/fall time of the LVDS
clock driving the LO_ is required to be 0.5ns, reference noise less than 10nV/√Hz from 1kHz to 20MHz, DOUT loaded with 10MΩ
and 60pF. Typical values are at V
CC1
= 3.3V, V
CC2
= 5V, T
A
= +25°C, unless otherwise noted.)
TWO-TONE ULTRASOUND-SPECIFIC IMD3
vs. FREQUENCY
MAX2078 toc13
FREQUENCY (MHz)
IMD3 (dBc)
15105
-60
-40
-20
0
-80
020
V
OUT
= 1V
P-P
GAIN = 26dB
ADJACENT CHANNEL-TO-CHANNEL
CROSSTALK vs. GAIN
MAX2078 toc14
GAIN (dB)
CROSSTALK (dBc)
352617
-65
-60
-55
-50
-70
844
V
OUT
= 1V
P-P
f
RF
= 10MHz
ADJACENT CHANNEL 1
ADJACENT CHANNEL 2
ADJACENT CHANNEL-TO-CHANNEL
CROSSTALK vs. FREQUENCY
MAX2078 toc15
FREQUENCY (MHz)
CROSSTALK (dBc)
10
-60
-30
0
-90
1100
V
OUT
= 1V
P-P
GAIN = 20dB
ADJACENT CHANNEL 1
ADJACENT CHANNEL 2