ADL5331ACPZ-R7 Analog Devices Inc, ADL5331ACPZ-R7 Datasheet - Page 12

• Manufacturer Part Number: ADL5331ACPZ-R7
• Description: Broadband Differential VGA
• Manufacturer: Analog Devices Inc

Specifications of ADL5331ACPZ-R7

• Current - Supply: 240mA
• Frequency: 1MHz ~ 1.2GHz
• Gain: 15dB
• Noise Figure: 9dB
• Package / Case: 24-VFQFN, CSP Exposed Pad
• Rf Type: CATV
• Test Frequency: 900MHz
• Voltage - Supply: 4.75 V ~ 5.25 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ADL5331ACPZ-R7; ADL5331ACPZ-R7TR

ADL5331
Figure 19 shows the basic connections for operating the
log detector in an automatic gain control (AGC) loop with the
ADL5331.
The gain of the ADL5331 is controlled by the output pin of the
AD8319. The voltage, V
avoid overdrive recovery issues, the AD8319 output voltage can
be scaled down using a resistive divider to interface with the
0.1 V to 1.4 V gain control range of the ADL5331.
A coupler/attenuation of 21 dB is used to match the desired
maximum output power from the VGA to the top end of the
linear operating range of the AD8319 (approximately −5 dBm
at 900 MHz).
Figure 20 shows the transfer function of the output power vs.
the V
with an input power of −1.5 dBm. Note that the power control
of the AD8319 has a negative sense. Decreasing V
corresponds to demanding a higher signal from the ADL5331,
increases gain.
This AGC loop is capable of controlling signals of ~30 dB,
which is the gain range limitation on the ADL5331. Across
the top 25 dB range of output power, the linear conformance
error is within ±0.5 dB over temperature.
SET
voltage over temperature for a 100 MHz sine wave
Figure 19. AD8319 Operating in Controller Mode to Provide Automatic Gain Control Functionality in Combination with the ADL5331
OUT
, has a range of 0 V to near V
SIGNAL
RFIN
DAC
220pF
10nF
10nF
SETPOINT
VOLTAGE
INHI
INLO
390Ω
VPOS
SET
+5V
VSET
CLPF
ADL5331
, which
VOUT
AD8319
GAIN
POS
LOG AMP
1kΩ
AD8319
COMM
COMM
. To
Rev. 0 | Page 12 of 16
OPLO
OPHI
VPOS
+5V
INLO
INHI
120nH
+5V
1nF
1nF
120nH
10nF
10nF
–10
–15
–20
20
15
10
–5
5
0
Figure 20. ADL5331 Output Power vs. AD8319 Setpoint Voltage,
0.6
0.7
0.8
10dB
DIRECTIONAL
COUPLER
10dB
ATTENUATOR
0.9
P
IN
= 0 dBm at 100 MHz
1.0
V
RFOUT SIGNAL
SET
1.1
(V)
+85°C
1.2
+25°C
1.3
–40°C
1.4
1.5
1.6
3.00
2.25
1.50
0.75
0
–0.75
–1.50
–2.25
–3.00