LT5554IUH#TRPBF Linear Technology, LT5554IUH#TRPBF Datasheet - Page 25

• Manufacturer Part Number: LT5554IUH#TRPBF
• Description: IC VGA DIG CONTROL 32-QFN
• Manufacturer: Linear Technology

Specifications of LT5554IUH#TRPBF

• Applications: Variable Gain (VGA)
• Number Of Circuits: 1
• -3db Bandwidth: 1GHz
• Current - Supply: 200mA
• Voltage - Supply, Single/dual (±): 4.75 V ~ 5.25 V
• Mounting Type: Surface Mount
• Package / Case: 32-WFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Common mode characterization for the LT5554 was per-
formed with input circuit shown in Figure 19.
Timing characterization and AC-coupled gain control inputs
are tested on evaluation board. The required circuit modi-
fi cations are shown in the Figure 20 simplifi ed schematic
and detailed below for PG6 (8dB step). The PG6 pulse
APPLICATIONS INFORMATION
50
J1
50
J1
Figure 19. Common Mode Input Interface
V
V
ENB = 5V
47nF
CC
CCO
C1
1, 3, 5, 7
0.1μF
= 5V
ETC1-1-13
= 8V
C4
MACOM
25Ω
V
•
CC
1:1
T1
•
V
DEC
0.1μF
9
Figure 18. Wideband Differential Output Test Board (Simplifi ed Schematic)
C8
25Ω
25Ω
C
47nF
11
DEC
ENB
13
PG0
C5
1μF
R20
10k
15
IN
IN
IN
DEC
IN
PG1
+
–
PG0
+
–
R
OUT
17
–
+
R21
OUT
OUT
PG2
R
50Ω
10k
400Ω
IN
= 50Ω
LT5554
PG1
R
–
+
19
O
5554 F19
PG3
OUT
OUT
R22
10k
21
–
+
LT5554
PG2
PG4
400Ω
R
O
R23
23
10k
PG5
PG3
R
57Ω
LOAD
25
PG6
R24
10k
66.5Ω
66.5Ω
source is applied at J6 connector and 50Ω terminated by
R16 and R33 resistors. C66 decouple R33 to ground while
C16 provides DC-decoupling between referenced to ground
pulse source and the PG6 DC-voltage. A supply connected
to PG6 turret will set the PG6 DC-voltage in 0V to 5V range.
All other (untested) PGx DC-voltage can be independently
be applied at V
Strobe-mode operation is tested with a pulse source ap-
plied at J7 connector as shown in Figure 20.
Applying similar modifi cations around J2 and J4 connec-
tors shown in Figure 21, other PGx inputs can be evaluated.
As described in Table 1 and Table 2, the MODE pin will
select the desired state.
PG4
STROBE
R5
R6
27
R25
10k
PG5
0.1μF
R26
C3
10k
V
PG
29
PG6
MATCHING
100Ω
PG
0.1μF
31
MODE
C9
turret decoupled by C88.
33, 35, 37, 38
0.1μF
47nF
47nF
C10
C12
C18
V
CCO
4.7μF
C19
J5, 40 PINS
SMT-TB
2, 4, ...40
5554 F18
LT5554
J3
50
J33
50
25
5554f