Features: Supports DOCSIS Standard for Reverse Path
Transmission
Gain Programmable in 0.75 dB Steps over a 53.5 dB
Low Distortion at 65 dBmV Output
62 dBc SFDR at 21 MHz
58 dBc SFDR at 65 MHz
1 dB Compression of 25 dBm at 10 MHz
Output Noise Level
45 dBmV in 160 kHz
Maintains 75 Output Impedance
Power-Up and Power-Down Condition
Upper Bandwidth: 100 MHz (Full Gain Range)
Single or Dual Supply Operation
APPLICATIONS
Gain-Programmable Line Driver
CATV Telephony Modems
CATV Terminal Devices
General-Purpose Digitally Controlled Variable Gain Block
Pinout
SpecificationsSupply Voltage VCC
Pins 5, 9, 10, 19, 20, 23, 27 .For ARP, Max VCC= VEE+ 13 V;
. . . . . . . . . . . . . . . . . . . . . . .For ARE, Max VCC= VEE+ 11 V
Input VoltagesPins
25, 26 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±0.5 V
Pins 1, 2, 3, 6, 7 . . . . . . . . . . . . . . . . . . . . . 0.8 V to +5.5 V
Internal Power Dissipation
TSSOP EPAD . . . . . . . . . . . . . . . . . . . . . . . ...... . . . . . . 1.5 W
PSOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .2.0 W
Operating Temperature Range . . . . . . . . . . 40°C to +85°C
Storage Temperature Range . . . . . . . . . . 65°C to +150°C
Lead Temperature, Soldering 60 seconds . .. . . . . . . . 300°C
| Gain Control |
Digital |
| -3 dB BW (MHz) |
100MHz |
| Gain Low End (dB) |
-26dB |
| Gain High End (dB) |
+27.5dB |
| Number of Channels |
1 |
| Spectral Noise (nV/rtHz) |
100nV/rtHz |
| Supply Voltage (V) |
±5V |
| Supply Current |
157mA |
| Gain Accuracy (dB) |
±1dB |
DescriptionThe AD8326 is a high-output power, digitally controlled, vari- able gain amplifier optimized for coaxial line driving applications such as data and telephony cable modems that are designed to the MCNS-DOCSIS upstream standard. An 8-bit serial word determines the desired output gain over a 53.5 dB range result- ing in gain changes of 0.75 dB/LSB. The AD8326 is offered in two models, each optimized to support the desired output power and resulting performance.
The AD8326 comprises a digitally controlled variable attenuator of 0 dB to 54 dB, that is preceded by a low noise, fixed-gain buffer and is followed by a low distortion high-power amplifier. The AD8326 accepts a differential or single-ended input signal. The output is designed to drive a 75 Ωload, such as coaxial cable, although the AD8326 is capable of driving other loads.
When driving 67 dBm into a 75 Ω load, the AD8326ARP provides a worst harmonic of only 59 dBc at 21 MHz and 57 dBc at 42 MHz. W hen driving 65 dBmV into a 75 Ω load, the AD8326ARE provides a worst harmonic of only 62 dBc at 21 MHz and 60 dBc at 42 MHz.
AD8326 Data Sheet
