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Ac electrical characteristics—vga mode – Rainbow Electronics MAX2038 User Manual

Page 4

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MAX2038

Ultrasound VGA Integrated
with CW Octal Mixer

4

_______________________________________________________________________________________

AC ELECTRICAL CHARACTERISTICS—VGA MODE

(

Typical Application Circuit, Figure 7. V

CC

= V

REF

= 4.75V to 5.25V, V

CM

= (3/5)V

REF

, T

A

= 0

°C to +70°C, V

GND

= 0, LOW_PWR = 0,

M4_EN = 0, CW_FILTER = 1, TMODE = 0, PD = 0, CW_VG = 1, CW_M1 = 0, CW_M2 = 0, VG_CLAMP_MODE = 1, f

RF

= f

LO

/16 =

5MHz, capacitance to GND at each of the VGA differential outputs is 60pF, differential capacitance across the VGA outputs is 10pF,
R

L

= 1k

Ω, CW mixer outputs pulled up to +11V through four separate ±0.1% 115Ω resistors, differential mixer inputs are driven from

a low impedance source. Typical values are at V

CC

= V

REF

= 5V, T

A

= +25

°C, unless otherwise noted.) (Note 2)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

Mode Select Response Time

CW_VG set from logic 1 to 0 or from 0 to 1
(Note 9)

2

µs

VGA MODE

Differential output
capacitance is 10pF,
capacitance to GND
at each single-ended
output is 60pF,
R

L

= 1k

Ω

18

Full-Scale Bandwidth

f-1.3dB

V

OUT

= 1.5V

P-P

,

1.3dB bandwidth,
gain = 10dB

No capacitive load
R

L

= 1k

Ω

29

MHz

Small-Signal Bandwidth

f-1.3dB

V

OUT

= 1.5mV

P-P

, 3dB bandwidth,

gain = 10dB

30

MHz

Differential Input Resistance

R

IN

170

200

230

Ω

Input Effective Capacitance

C

IN

f

RF

= 10MHz, each input to ground

15

pF

Differential Output Resistance

R

OUT

100

Ω

Maximum Gain

+29.5

dB

Minimum Gain

-12.5

dB

Gain Range

42

dB

Absolute Gain Error

T

A

= +25

°C, full gain range 0% to 100%,

V

REF

= 5V

±0.25

±1.5

dB

VGA Gain Response Time

40dB gain change to within 1dB final value

1

µs

Input-Referred Noise

VG_CTL set for maximum gain,
no input signal

2

nV/

√Hz

No input signal

22

Output-Referred Noise

VG_CTL set for
+10dB of gain

V

OUT

= 1.5V

P-P

, 1kHz

offset

55

nV/

√Hz

V G_C LAM P _M OD E = 1, V G_C TL set for
+ 10d B of g ai n, f

R F

= 5M H z, V

OU T

= 1.5V

P - P

-70

Second Harmonic

HD2

V G_C LAM P _M OD E = 1, V G _C TL set for
+ 10d B of g ai n, f

R F

= 10M H z, V

OU T

= 1.5V

P - P

-55

-65

dBc

Third-Order Intermodulation
Distortion

IMD3

V G_C LT set for + 10d B of g ai n, f

RF1

= 5M H z,

f

R F2

= 5.01MHz, V

OUT

= 1.5V

P-P

,

V

REF

= 5V (Note 3)

-40

-52

dBc

Channel-to-Channel Crosstalk

V

OUT

= 1V

P-P

differential, f

R F

= 10MHz,

VG_CTL set for +10dB of gain

-80

dB

Maximum Output Voltage at
ClampON

VG_CLAMP_MODE = 0, VG_CTL set for
+20dB of gain, 350mV

P-P

differential input

2.4

V

P-P

d i ffer enti al