AD603ARZ Analog Devices Inc, AD603ARZ Datasheet - Page 10

• Manufacturer Part Number: AD603ARZ
• Description: IC AMP VGA 90MHZ LN 50MA 8SOIC
• Manufacturer: Analog Devices Inc
• Series: X-AMP®r
• Type: Var Gain Ampr

Specifications of AD603ARZ

• Amplifier Type: Variable Gain
• Number Of Circuits: 1
• Slew Rate: 275 V/µs
• -3db Bandwidth: 90MHz
• Current - Input Bias: 200nA
• Current - Supply: 12.5mA
• Current - Output / Channel: 50mA
• Voltage - Supply, Single/dual (±): 9.5 V ~ 12.6 V, ±4.75 V ~ 6.3 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• No. Of Amplifiers: 1
• Bandwidth: 90MHz
• Gain Accuracy: 1.5dB
• No. Of Channels: 1
• Supply Voltage Range: ± 4.75V To ± 6.3V
• Amplifier Case Style: SOIC
• No. Of Pins: 8
• Number Of Channels: 1
• Number Of Elements: 2
• Power Supply Requirement: Dual
• Voltage Gain Db: 31.3dB
• Input Resistance: 0.000103@±5VMohm
• Input Bias Current: 0.2@±5VnA
• Single Supply Voltage (typ): Not RequiredV
• Dual Supply Voltage (typ): ±5V
• Power Dissipation: 400mW
• Rail/rail I/o Type: No
• Single Supply Voltage (min): Not RequiredV
• Single Supply Voltage (max): Not RequiredV
• Dual Supply Voltage (min): ±4.75V
• Dual Supply Voltage (max): ±6.3V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 8
• Package Type: SOIC N
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AD603-EVALZ - BOARD EVALUATION FOR AD603
• Output Type: -
• Gain Bandwidth Product: -
• Voltage - Input Offset: -
• Lead Free Status / Rohs Status: Compliant

AD603
With reference to Figure 6, note that V
tial gain-control input to A1, and V
gain-control input to A2. When V
thus the gain of A1 is –8.93 dB (recall that the gain of each indi-
vidual amplifier in the maximum bandwidth mode is –10 dB
for V
–1.908 V so the gain of A2 is pinned at –11.07 dB. The overall
gain is thus –20 dB. This situation is shown in Figure 6a.
When V
which sets the gain of A1 to at nearly its maximum value of
31.07 dB, while V
A2’s gain at nearly its minimum value –11.07 dB. Close analysis
shows that the degree to which neither AD603 is completely
pushed to its maximum or minimum gain exactly cancels in the
overall gain, which is now +20 dB. This is depicted in Figure 6b.
GAIN
(dB)
G
Figure 7. Explanation of Offset Calibration for
Sequential Control
–8.93dB
–22.14
= –500 mV and 10 dB for V
G
= +1.00 V, V
+31.07dB
+10dB
–20
0
G2
*
0.473
GAIN OFFSET OF 1.07dB, OR 26.75mV
A1
= 1.00 V – 1.526 V = 0.526 V, which sets
Figure 6. AD603 Gain Control Input Calculations for Sequential Control Operation
0.5
0
G1
–11.07dB
*
= 1.00 V – 0.473 V = +0.526 V,
INPUT
V
V
INPUT
INPUT
V
C
C
C
0dB
0dB
0dB
= 2.0V
= 1.0V
1.0
= 0V
20
G
+31.07dB
G2
G
is 0, V
*
= 0 V); meanwhile, V
GPOS
GPOS
GPOS
refers to the differential
G1
A2
1.50
40
–42.14dB
refers to the differen-
G1
0dB
V
0dB
1.526
V
V
G1
0dB
G1
G1
0dB
= –473 mV and
GNEG
GNEG
GNEG
–40.00dB
V
V
V
O1
O1
O1
A1
2.0
60
= 0.473V
= 0.473V
= 0.473V
–11.07dB
+28.96dB
31.07dB
31.07dB
31.07dB
V
62.14
C
(V)
G2
–8.93dB
31.07dB
31.07dB
=
–10–
b.
a.
c.
GPOS
GPOS
When V
that of A2 is near its maximum value of 28.93 dB, resulting in
an overall gain of 60 dB (see Figure 6c). This mode of operation
is further clarified by Figure 8, which is a plot of the separate
gains of A1 and A2 and the overall gain versus the control voltage.
Figure 9 is a plot of the SNR of the cascaded amplifiers versus the
control voltage. Figure 10 is a plot of the gain error of the cas-
caded stages versus the control voltages.
GPOS
–42.14dB
–42.14dB
–2.14dB
V
V
V
G2
G2
G2
Figure 8. Plot of Separate and Overall Gains in
Sequential Control
–10
–20
–30
GNEG
GNEG
GNEG
G
70
60
50
40
30
20
10
–51.07dB
–28.93dB
0
–0.2
–11.07dB
V
V
V
= 2.0 V, the gain of A1 is pinned at 31.07 dB and
O2
O2
O2
A2
= 1.526V
= 1.526V
= 1.526V
31.07dB
31.07dB
31.07dB
0.2
0.6
OUTPUT
–20dB
OUTPUT
60dB
A1
OUTPUT
20dB
1.0
V
C
COMBINED
1.4
A2
1.8
2.2
REV. E