Datasheet

MAX2078
Octal-Channel Ultrasound Front-End
with CW Doppler Mixers
12 ______________________________________________________________________________________
LNA OVERLOAD RECOVERY TIME
(V
IN
= 500mV
P-P
for 1
μ
s TO 100mV
P-P
for 1
μ
s
AND BACK TO 500mV
P-P
for 1
μ
s, GAIN = 10dB)
TIME (ns)
OUTPUT (V)
1500500 1000
-0.25
0.25
0.75
1.25
-0.75
0
2000
MAX2078 toc19
INPUT (V)
0
-0.5
-1.0
-1.5
0.5
INPUT
OUTPUT
OUTPUT (V)
-1
0
1
2
3
-2
VGA OVERLOAD RECOVERY TIME
(V
IN
= 40mV
P-P
for 1
μ
s TO 4mV
P-P
for 1
μ
s
AND BACK TO 40mV
P-P
for 1
μ
s, GAIN = 42.5dB)
MAX2078 toc20
INPUT (V)
0
-0.05
-0.10
-0.15
0.05
OUTPUT
TIME (ns)
1500500 10000 2000
INPUT
OVERDRIVE PHASE DELAY
vs. FREQUENCY
MAX2078 toc21
FREQUENCY (MHz)
PHASE DELAY (ns)
9
18
27
36
45
0
155 10020
GAIN = 10dB
INPUT = 300mV
P-P
INPUT = 30mV
P-P
GROUP DELAY vs. FREQUENCY
MAX2078 toc22
GROUP DELAY (ns)
25
35
45
15
FREQUENCY (MHz)
155 10020
GAIN = 10dB
GAIN = 20dB
GAIN = 40dB
GAIN = 30dB
CW IMD3 vs. FREQUENCY
MAX2078 toc23
FREQUENCY (MHz)
CW IMD3 (dBc)
642
-60
-56
-52
-48
-64
0
8
V
IN
= 100mV
P-P
INPUT-REFERRED NOISE
vs. INPUT CLUTTER VOLTAGE
MAX2078 toc24
INPUT CLUTTER VOLTAGE (mV
P-P
)
15010050
1.32
1.36
1.40
1.44
1.48
1.28
0
200
NOISE (nV/√Hz)
f
CLUTTER
= 1.25MHz
OFFSET = 1kHz
LOW-POWER MODE
NORMAL POWER MODE
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.)