AD604-EVALZ Analog Devices Inc, AD604-EVALZ Datasheet - Page 22

• Manufacturer Part Number: AD604-EVALZ
• Description: BOARD EVAL FOR AD604 AMP
• Manufacturer: Analog Devices Inc
• Series: X-AMP®r

Specifications of AD604-EVALZ

• Channels Per Ic: 2 - Dual
• Amplifier Type: Variable Gain
• Output Type: Single-Ended
• Slew Rate: 170 V/µs
• -3db Bandwidth: 40MHz
• Current - Output / Channel: 40mA
• Operating Temperature: -40°C ~ 85°C
• Current - Supply (main Ic): 32mA
• Board Type: Fully Populated
• Utilized Ic / Part: AD604
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply, Single/dual (±): -
• Lead Free Status / RoHS Status: Supplier Unconfirmed, Lead free / RoHS Compliant

AD604
MEDICAL ULTRASOUND TGC DRIVING THE
AD9050, A 10-BIT, 40 MSPS ADC
The AD604 is an ideal candidate for the time gain control (TGC)
amplifier that is required in medical ultrasound systems to limit
the dynamic range of the signal that is presented to the ADC.
Figure 52 shows a schematic of an AD604 driving an
in a typical medical ultrasound application.
ANALOG
INPUT
J2
0.1µF
0.1µF
VREF
50Ω
0.1µF
50Ω
0.1µF
DIGITAL GAIN CONTROL
10
11
12
10
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
–DSX1
+DSX1
PAO1
FBK1
PAI1
COM1
COM2
PAI2
FBK2
PAO2
+DSX2
–DSX2
V
V
V
V
AGND
DGND
DB7
(MSB)
DB6
DB5
DB4
OUT
OUT
SS
REF
AD7226
AD604
B
A
100Ω
V
V
VOCM
VNEG
VNEG
VGN1
GND1
VPOS
VPOS
GND2
VGN2
VREF
OUT1
OUT2
(LSB)
OUT
OUT
DB0
DB1
DB2
DB3
V
WR
A0
A1
DD
Figure 52. TGC Circuit for Medical Ultrasound Application
C
D
20
19
18
17
16
15
14
13
12
11
24
23
22
21
20
19
18
17
16
15
14
13
0.1µF
1kΩ
AD9050
0.1µF
+15V
FILTER
0.1µF
0.1µF
Rev. G | Page 22 of 32
+5V
–5V
1kΩ
2
3
The gain is controlled by means of a digital byte that is input to
an
The output common-mode voltage of the AD604 is set to VPOS/2
by means of an internal voltage divider. The VOCM pin is
bypassed with a 0.1 μF capacitor to ground.
The DSX output is optionally filtered and then buffered by
an
op amp output is ac-coupled into the self-biasing input of an
AD9050
sampling rate.
–IN
+IN
AD7226
AD9631
OPTIONAL
1kΩ
AD9631
OUT
ADC that is capable of outputting 10 bits at a 40 MSPS
0.1µF
6
op amp, a low distortion, low noise amplifier. The
DAC that outputs the analog gain control signal.
0.1µF
0.1µF
0.1µF
10
13
14
3
4
5
6
9
AIN
VREF
VREF
COMP
REF
AINB
ENCODE
OR
AD9050
BP
OUT
IN
(MSB) D9
(LSB) D0
V
V
D8
D7
D6
D5
D4
D3
D2
D1
DD
DD
15
16
17
18
19
24
25
26
27
28
20
22
CLK
A/D
OUTPUT