Datasheet

250MHz to 4000MHz Dual,
Analog Voltage Variable Attenuator
MAX19790
10
Typical Application Circuit
Exposed Pad RF and Thermal
Considerations
The exposed pad (EP) of the device’s 36-pin thin QFN
package provides a low thermal-resistance path to
the die. It is important that the PCB on which the IC is
mounted be designed to conduct heat from this contact.
In addition, provide the EP with a low-inductance RF
ground path for the device.
The EP MUST be soldered to a ground plane on the
PCB, either directly or through an array of plated via
holes. Soldering the pad to ground is also critical
for efficient heat transfer. Use a solid ground plane
wherever possible.
C1
RFA
CTRL
V
CC
R4
R3
IN_B
GND
2 3 4 5 6 7 8 9
10
11
12
13
14
15
16
17
18
192021222324252627
28
29
ATTEN_B
ATTEN_A
EP
30
31
32
33
34
35
36
OUT_A
GND
IN_A
OUT_B
1
ATTENUATION-
CONTROL
CIRCUITRY
*SCHEMATIC SHOWS CONFIGURATION FOR TWO CASCADED ATTENUATORS. TO USE ATTENUATOR A ONLY MOVE C3
TO CONNECT OUT_A TO RFB. TO USE ATTENUATOR B ONLY MOVE C3 TO CONNECT RFB TO IN_B.
GND GND GND GND GND
R1
C2
V
CC
V
CC
CTRL
C9
C8
C6
C7
V
CC
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
RFB*
C3
V
CC
C4
R2
C5
RFOUT
V
CC
GND GND GND GND GND GND GND GND GND
MAX19790