LTC5598IUF LINER [Linear Technology], LTC5598IUF Datasheet - Page 14

• Manufacturer Part Number: LTC5598IUF
• Description: 5MHz to 1600MHz High Linearity Direct Quadrature Modulator
• Manufacturer: LINER [Linear Technology]

LTC5598
APPLICATIONS INFORMATION
this occur, the supply current could be sourced through
the EN pin ESD protection diodes, which are not designed
to carry the full supply current, and damage may result.
Evaluation Board
Figure 10 shows the evaluation board schematic. A good
ground connection is required for the exposed pad. If this
is not done properly, the RF performance will degrade.
Additionally, the exposed pad provides heat sinking for the
part and minimizes the possibility of the chip overheating.
Resistors R1 and R2 reduce the charging current in
capacitors C1 and C4 (see Figure 10) and will reduce
supply ringing during a fast power supply ramp-up in
case an inductive cable is connected to the V
turrets. For EN = High, the voltage drop over R1 and R2
is about 0.15V. If a power supply is used that ramps up
slower than 10V/μs and limits the overshoot on the supply
below 5.6V, R1 and R2 can be omitted.
The LTC5598 can be used for base-station applications
with various modulation formats. Figure 13 shows a
typical application.
14
LOM
LOP
J3
J5
GND
3.3nH
3.3nH
C9
2.2pF
C10
2.2pF
L1
L2
BBMQ
Figure 10. Evaluation Circuit Schematic
BBMI
10nF
C5
J1
J6
EN
10nF
C7
C1
4.7μF
1
2
3
4
5
6
C8
470nF
EN
GND
LOP
LOM
GND
CAPA
C2
1nF
24 23 22 21 20 19
7 8
BOARD NUMBER: DC1455A
9 10 11 12
1Ω
R1
GNDRF
GNDRF
V
25
CC2
NC
NC
RF
J2
18
17
16
15
14
13
BBPI
LTC5598
CC
U1
R2
5.6Ω
10nF
C6
and GND
C3
1nF
V
CC
GND
J4
J7
5598 F10
RF OUT
BBPQ
C4
4.7μF
Figure 11. Component Side of Evaluation Board
Figure 12. Bottom Side of Evaluation Board
5598f