Features: Digitally Controlled Variable Gain in 3 dB Steps
5 dB to +40 dB (RL = 1 k)
10 dB to +35 dB (RL = 200 )
Less than 0.2 dB Flatness over a +20 MHz Bandwidth
up to 380 MHz
4-Bit Parallel or 3-Wire Serial Interface
Differential 200 Input and Output Impedance
Single 3.0 V5.5 V Supply
Draws 37 mA at 5 V
Power-Down <1 mA Maximum
APPLICATIONS
Cellular/PCS Base Stations
IF Sampling Receivers
Fixed Wireless Access
Wireline Modems
InstrumentationPinout
SpecificationsSupply Voltage VS, VPOS . . . . . . . . . . . . . . . . . . . . . . . .. . . 5.5 V
PWUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VS + 200 mV
BIT0, BIT1, BIT2, BIT3, DENB, SENB . . . . . .. . .. . .. . VS + 200 mV
Input Voltage, VINHI VINLO . . . . . . . . . . . . . . . . . . . . . . . . 4 V
Input Voltage, VINHI or VINLO with respect to COMM . . . . . . . 4.5 V
Input Voltage, VINHI VINLO with respect to COMM
............................................................................... COMM 200 mV
Internal Power Dissipation . . . . . . . . . . . . . . . . . . . . .. . . .. 265 mW
JA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 150C/W
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . .125C
Operating Temperature Range . . . . . . . . . . . . . . 40C to +85C
Storage Temperature Range . . . . . . . . . . . . . . .65C to +150C
Lead Temperature Range (soldering 60 sec) . . . . . . .. . . to 300C
| Gain Control |
Digital |
| -3 dB BW (MHz) |
600MHz |
| Gain Low End (dB) |
-5dB |
| Gain High End (dB) |
+40dB |
| Number of Channels |
1 |
| Spectral Noise (nV/rtHz) |
2nV/rtHz |
| Supply Voltage (V) |
+5.5V |
| Supply Current |
37mA |
| Gain Accuracy (dB) |
±0.5dB |
DescriptionThe AD8369 is a high performance digitally controlled variable gain amplifier (VGA) for use from low frequencies to a 3 dB frequency of 600 MHz at all gain codes. The AD8369 delivers excellent distortion performance: the two-tone, third-order intermodulation distortion is 69 dBc at 70 MHz for a 1 V p-p composite output into a 1 kW load. The AD8369 has a nominal noise figure of 7 dB when at maximum gain, then increases with decreasing gain. Output IP3 is +19.5 dBm at 70 MHz into a 1 kW load and remains fairly constant over the gain range.
The signal input is applied to pins INHI and INLO. Variable gain is achieved via two methods. The 6 dB gain steps are implemented using a discrete X-AMP® structure, in which the input signal is progressively attenuated by a 200 W R-2R ladder network that also sets the input impedance; the 3 dB steps are implemented at the output of the amplifier. This combination provides very accurate 3 dB gain steps over a span of 45 dB. The output imped- ance is set by on-chip resistors across the differential output pins,
AD8369 Data Sheet
