AD8331ARQ-REEL Analog Devices Inc, AD8331ARQ-REEL Datasheet - Page 24

• Manufacturer Part Number: AD8331ARQ-REEL
• Description: IC VGA SINGLE W/PREAMP 20-SSOP
• Manufacturer: Analog Devices Inc
• Series: X-AMP®r
• Type: Variable Gain Amplifierr

Specifications of AD8331ARQ-REEL

• Rohs Status: RoHS non-compliant
• Design Resources: Interfacing the High Frequency AD8331 to AD9215 (CN0096)
• Applications: Signal Processing
• Mounting Type: Surface Mount
• Package / Case: 20-QSOP
• For Use With: AD8331-EVALZ - BOARD EVAL FOR AD8331

AD8331/AD8332/AD8334
THEORY OF OPERATION
OVERVIEW
The
Figure 69, Figure 70, and Figure 71 are functional block
diagrams of the three devices
LMD
LMD1
LMD2
INH
INH1
INH2
AD8331/AD8332/AD8334
+19dB
+
–
LNA
LNA 1
LNA 2
LON
LON2 LOP2
LON1 LOP1
BIAS
VCM
Figure 69. AD8331 Functional Block Diagram
Figure 70. AD8332 Functional Block Diagram
LOP
LNA V
VIP
MID
ENBL
VIP1
VIP2
VIN
–
+
INTERPOLATOR
VGA BIAS AND
ATTENUATOR
VIN1
VIN2
– ATTENUATOR
+
+ ATTENUATOR
–
INTERPOLATOR
–48dB
VGA BIAS AND
AD8331
ENBV
AD8332
–48dB
–48dB
ENB
operate in the same way.
VCM
V
MID
GAIN INT
VCM1
VCM2
V
V
21dB
GAIN
MID
MID
GAIN
INT
21dB
21dB
CLAMP
CLAMP
15.5dB
3.5dB/
15.5dB
PA
3.5dB/
PA1
PA2
HILO
HILO
VOH
VOL
RCLMP
MODE
VOH1
VOL1
GAIN
VOH2
VOL2
RCLMP
Rev. G | Page 24 of 56
MODE
Each channel contains an LNA that provides user-adjustable input
impedance termination, a differential X-AMP VGA, and a pro-
grammable gain postamp with adjustable output voltage limiting.
Figure 72 shows a simplified block diagram with external
components.
INH
LMD1
LMD2
LON2
LON3
LMD3
LMD4
LOP2
LOP3
INH1
INH2
INH3
INH4
VIP2
VIN2
VIN3
VIP3
PREAMPLIFIER
LON4
LNA 1
LNA 2
LNA 3
LNA 4
LMD
LNA
LON1 LOP1 VIP1 VIN1 EN12
19dB
BIAS
VCM
Figure 71. AD8334 Functional Block Diagram
BIAS
VCM
LOP4
BIAS
VCM
LON
LOP
Figure 72. Simplified Block Diagram
VIP4
VIN4
– ATTENUATOR
+
+ ATTENUATOR
–
– ATTENUATOR
+
+ ATTENUATOR
–
INTERPOLATOR
INTERPOLATOR
VIN
VGA BIAS AND
VGA BIAS AND
VIP
ATTENUATOR
AD8334
GAIN UP/
–48dB
–48dB
DOWN
–48dB
–48dB
EN34
48dB
SIGNAL PATH
V
VCM4
V
V
VCM1
V
MID4
MID2
MID3
MID1
V
VCM
MID
GAIN
GAIN
21dB
21dB
21dB
21dB
INT
INT
INTERFACE
21dB
GAIN
GAIN
3.5dB/15.5dB
POSTAMP
CLAMP
CLAMP
PA1
PA2
PA3
PA4
CLAMP
HILO
RCLMP
CLMP12
VOH1
VOL1
GAIN12
HILO
VOL2
VOH2
VCM2
VCM3
VOH3
VOL3
GAIN34
VOL4
VOH4
CLMP34
VOH
VOL