Data Sheet ADL5541
BASIC CONNECTIONS
The basic connections for operating the ADL5541 are shown in
Figure 20. Recommended components are listed in Table 5. The
input and output should be ac-coupled with appropriately sized
capacitors (device characterization was performed with 33 pF
capacitors). A 5 V dc bias is supplied to the amplifier via GND
(Pin 6) and through a biasing inductor connected to RFOUT
(Pin 8). The bias voltage should be decoupled using a 1 µF
capacitor, a 1.2 nF capacitor, and two 68 pF capacitors.
VCC
ADL5541
C4
68pF
C5
1.2nF
C6
1µF
VCC
C2
33pF
C1
33pF
RFIN RFOUT
L1
47nH
C3
1µF
GND
C7
68pF
06877-013
GND GND
CB VPOS
RFIN RFOUT
GND GND
1
2
3
4
8
7
6
5
Figure 20. Basic Connections
For operation below 500 MHz, a larger biasing choke and ac
coupling capacitors are necessary (see Table 5). Figure 21 shows
input return loss, output return loss, and gain for frequencies
between 200 MHz and 500 MHz. The noise figure performance
for operation from 200 MHz to 500 MHz is shown in Figure 22.
–30
–25
–20
–15
–10
–5
12.0
12.5
13.0
13.5
14.0
14.5
15.0
15.5
16.0
16.5
17.0
200
250
300 350 400 450 500
RETURN LOSS (dB)
GAIN (dB)
FREQUENCY (MHz)
S11
S22
S21
06877-121
Figure 21. Input Return Loss (S11), Output Return Loss (S22), and
Gain (S21) vs. Frequency
2.0
2.5
3.0
3.5
4.0
4.5
200 250 300 350 400 450 500
NOISE FIGURE (dB)
FREQUENCY (MHz)
06877-122
Figure 22. Noise Figure vs. Frequency from 200 MHz to 500 MHz
SOLDERING INFORMATION AND RECOMMENDED
PCB LAND PATTERN
Figure 23 shows the recommended land pattern for the ADL5541.
To minimize thermal impedance, the exposed paddle on the
package underside should be soldered down to a ground plane
along with Pin 2, Pin 3, Pin 6, and Pin 7. If multiple ground
layers exist, they should be stitched together using vias (a
minimum of five vias is recommended). For more information
on land pattern design and layout, refer to Application Note
AN-772, A Design and Manufacturing Guide for the Lead Frame
Chip Scale Package (LFCSP).
PIN 1
PIN 4
PIN 8
PIN 5
1.85mm
2.03mm
1.78mm0.5mm
0.71mm
1.53mm
06877-016
Figure 23. Recommended Land Pattern
Table 5. Recommended Components for Basic Connections
Frequency C1 C2 C3 L1 C4 C5 C6 C7
20 MHz to 200 MHz 0.1 µF 0.1 µF 1 µF 1 µH (Coilcraft 0805LS-102XJL_ or equivalent) 68 pF 1.2 nF 1 µF 68 pF
200 MHz to 500 MHz 0.1 µF 0.1 µF 1 µF 470 nH (Coilcraft 0603LS-471-NX or equivalent) 68 pF 1.2 nF 1 µF 68 pF
500 MHz to 6000 MHz 33 pF 33 pF 1 µF 47 nH (Coilcraft 0603CS-47-NX or equivalent) 68 pF 1.2 nF 1 µF 68 pF
Rev. B | Page 11 of 13
