Datasheet
MAX2078
Octal-Channel Ultrasound Front-End
with CW Doppler Mixers
6 _______________________________________________________________________________________
AC ELECTRICAL CHARACTERISTICS—VGA MODE (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,
V/C = 1, NP = 0, PD = 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
= 5MHz,
capacitance to GND at each of the VGA differential outputs is 25pF, differential capacitance across VGA outputs is 15pF, R
L
= 1kΩ
differential, 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
= 4.75V, T
A
= +25°C, unless otherwise noted.) (Note 5)
AC ELECTRICAL CHARACTERISTICS—CW MODE
(
Typical Application Circuit
, V/C = 0, PD = 0, NP = 0, CLP = 0, D43/D42/D41/D40 = 1/0/1/0 (R
IN
= 200Ω, LNA gain = 18.5dB), f
RF
=
f
LO
/16 = 5MHz, 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 (Note 12). Typical values are at
V
CC1
= 3.3V, V
CC2
= 4.75V, T
A
= +25°C, unless otherwise noted.) (Note 5)
PARAMETER CONDITIONS MIN TYP MAX UNITS
CW DOPPLER MIXER
Mixer RF Frequency Range 0.9 7.6 MHz
LO Frequency Range LO+ and LO- 16 120 MHz
Mixer Output Frequency Range DC 100 kHz
FULL-POWER MODE
Noise Figure No carrier 3.4 dB
Noise Figure at 100mV
P-P
Input
100mV
P-P
at input, f
RF
= f
LO
/16 = 1.25MHz, measured at
1kHz offset
3.6 dB
Noise Figure at 200mV
P-P
Input
200mV
P-P
at input, f
RF
= f
LO
/16 = 1.25MHz, measured at
1kHz offset
4.1 dB
SNR at 100mV
P-P
Input
100mV
P-P
at input, f
RF
= f
LO
/16 = 1.25MHz, measured at
1kHz offset
-148.3 dBc/Hz
SNR at 200mV
P-P
Input
200mV
P-P
at input, f
RF
= f
LO
/16 = 1.25MHz, measured at
1kHz offset
-153.8 dBc/Hz
PARAMETER CONDITIONS MIN TYP MAX UNITS
3V Supply Modulation Ratio
Gain = 28dB, V
VG+
- V
VG
-
= 0.4V, V
OUT
= 1V
P-P
,
f
RF
= 5MHz, f
MOD
= 1kHz, V
MOD
= 50mV
P-P
, ratio of
output sideband at 5.001MHz, 1V
P-P
-73 dBc
4.75V/5V Supply Modulation
Ratio
Gain = 28dB, V
VG+
- V
VG
- = 0.4V, V
OUT
= 1V
P-P
,
f
RF
= 5MHz, f
MOD
= 1kHz, V
MOD
= 50mV
P-P
, ratio of
output sideband at 5.001MHz, 1V
P-P
-82 dBc
Gain Control Lines Common-
Mode Rejection Ratio
Gain = 28dB, V
VG+
- V
VG
- = 0.4V, f
MOD
= 5MHz,
V
MOD
= 50mV
P-P
, V
OUT
= 1.0V
P-P
-74 dBc
Overdrive Phase Delay
V
VG+
- V
VG
- = -3V, delay between V
IN
= 300mV
P-P
and
V
IN
= 30mV
P-P
differential
5ns
Output Impedance Differential 100 Ω