Series 349 and 349H Octave-Band 11 Bit Digital PIN Diode Attenuators
Application Notes for Microwave Attenuators
The Series 349 and 349H programmable attenuators provide greater than octave-band performance and wide programming flexibility in compact rugged packages. Attenuation ranges up to 80 dB are available with attenuation increments as low as 0.03 dB.
Each Series 349 and 349H unit is
an integrated assembly of a balanced PIN diode attenuator and a driver
circuit. A standard version of the attenuator has a driver circuit
consisting of a PROM, a D/A converter and a current-to-voltage converter. See
Figure 1. The G10 glitch-free option (see Available Options list below)
driver circuit is based on an FPGA and a faster D/A converter designed for
smooth glitch-less transitions while switching between attenuation levels. Both
versions, the standard and the G10 option, provide a high degree of accuracy
and repeatability and preserves the inherent monotonicity of the
attenuator. Option G10 is recommended for new designs.
The maximum programmable attenuation range in every band except the 8.0–18.0 GHz frequency range is 80 dB. Attenuators limited in range to 64 dB exhibit switching times less than 500 nsec while the 80 dB units switch in less
than 2 µsec.
If even faster switching of 64 dB units is required,
GMC offers its Series 349H attenuators. These units switch in less
than 300 nsec with essentially the same performance specifications as the 64 dB Series 349 units.
All the attenuators
are available with either a strobe/ latch or a non-linear current or voltage controlled attenuation capability. Refer to the Available Options table and the Notes following the Pin Functions table.
- Absorptive
- 64 or 80 dB range
- 0.03 dB resolution
- Binary or BCD programming
- Guaranteed monotonicity
- Frequency range: 0.75 to 18GHz
PERFORMANCE CHARACTERISTICS: SERIES 349
MODEL |
FREQUENCY
RANGE
GHz |
MAX.
INSERTION
LOSS(dB) |
MAX.
VSWR |
MAX. FLATNESS (±dB)
AT MEAN ATTENUATION LEVELS UP TO |
10 dB |
20 dB |
40 dB |
60 dB (4) |
80 dB(1) |
3491-64
3491-80 |
1.0 - 2.0 |
1.6 |
1.5 |
0.3 |
0.8 |
1.5 |
1.6 |
1.9 |
0.75 - 2.25(2) |
1.7 |
2.0 |
0.5 |
1.4 |
3.0 |
3.5 |
3.8 |
3492-64
3492-80 |
2.0 - 4.0 |
1.8 |
1.5 |
0.3 |
0.8 |
1.5 |
1.6 |
1.9 |
1.5 - 4.5(2) |
1.9 |
2.0 |
0.5 |
1.4 |
3.0 |
3.5 |
3.8 |
3493-64
3493-80 |
2.6 - 5.2 |
2.0 |
1.6 |
0.3 |
0.8 |
1.5 |
1.6 |
1.9 |
1.95 - 5.85(2) |
2.1 |
2.1 |
0.5 |
1.4 |
3.0 |
3.5 |
3.8 |
3494-64
3494-80 |
4.0 - 8.0 |
2.4 |
1.7 |
0.3 |
0.8 |
1.5 |
1.6 |
1.9 |
3.0 - 9.0(2) |
2.5 |
2.2 |
0.5 |
1.4 |
3.0 |
3.5 |
3.8 |
3495-64
3495-80 |
5.0 - 10.0 |
2.6 |
1.7 |
0.5 |
0.9 |
1.5 |
1.6 |
1.9 |
3.75 - 11.25(2) |
2.7 |
2.2 |
0.7 |
1.4 |
3.0 |
3.5 |
3.8 |
3496-64
3496-80 |
6.0 - 12.0 |
2.7 |
1.8 |
0.7 |
1.0 |
1.5 |
1.6 |
1.9 |
4.5 - 13.5(2) |
2.8 |
2.2 |
0.9 |
1.5 |
3.0 |
3.5 |
3.8 |
3498-64 |
8.0 - 18.0 |
3.0(3) |
1.8(3) |
0.7 |
1.0 |
1.5 |
1.6 |
- |
6.0 - 18.0(2) |
3.0(3) |
1.8(3) |
0.9 |
1.5 |
3.0 |
3.5 |
- |
PERFORMANCE CHARACTERISTICS: SERIES 349H
MODEL |
FREQUENCY
RANGE
GHz |
MAX.
INSERTION
LOSS(dB) |
MAX.
VSWR |
MAX. FLATNESS (±dB)
AT MEAN ATTENUATION LEVELS UP TO |
10 dB |
20 dB |
40 dB |
60 dB (4) |
3491H-64 |
1.0 - 2.0 |
1.6 |
1.5 |
0.5 |
1.0 |
1.5 |
1.6 |
0.75 - 2.25(2) |
1.7 |
2.0 |
0.7 |
1.6 |
3.0 |
3.5 |
3492H-64
|
2.0 - 4.0 |
1.8 |
1.5 |
0.5 |
1.0 |
1.5 |
1.6 |
1.5 - 4.5(2) |
1.9 |
2.0 |
0.7 |
1.6 |
3.0 |
3.5 |
3493H-64
|
2.6 - 5.2 |
2.0 |
1.6 |
0.5 |
1.0 |
1.5 |
1.6 |
1.95 - 5.85(2) |
2.1 |
2.1 |
0.7 |
1.6 |
3.0 |
3.5 |
3494H-64
|
4.0 - 8.0 |
2.4 |
1.7 |
0.5 |
1.0 |
1.5 |
1.6 |
3.0 - 9.0(2) |
2.5 |
2.2 |
0.7 |
1.6 |
3.0 |
3.5 |
3495H-64
|
5.0 - 10.0 |
2.6 |
1.7 |
0.7 |
1.0 |
1.5 |
1.6 |
3.75 - 11.25(2) |
2.7 |
2.2 |
0.9 |
1.6 |
3.0 |
3.5 |
3496H-64
|
6.0 - 12.0 |
2.7 |
1.8 |
0.7 |
1.0 |
1.5 |
1.6 |
4.5 - 13.5(2) |
2.8 |
2.2 |
0.9 |
1.6 |
3.0 |
3.5 |
3498H-64 |
8.0 - 18.0 |
3.0(3) |
1.8(3) |
0.7 |
1.0 |
1.5 |
1.6 |
6.0 - 18.0(2) |
3.0(3) |
1.8(3) |
0.9 |
1.6 |
3.0 |
3.5 |
Mean Attenuation Range
|
|
349(X), 349(X)H-64.................................... |
64 dB |
|
349(X)-80.................................................... |
80 dB |
|
|
|
Accuracy of Attenuation |
|
0 to 30dB...................................................... |
± 0.5 dB |
|
> 30 to 50 dB................................................ |
± 1.0 dB |
|
> 50 to 64 dB................................................ |
± 1.5 dB |
|
> 64 to 80 dB................................................ |
± 2.0 dB |
|
|
|
Monotonicity..................................................................
|
Guaranteed |
|
|
|
Phase Shift.....................................................................
|
See Application Notes |
|
|
|
Temperature Coefficient................................................
|
± 0.025 dB/°C |
|
|
|
Power Handling Capability without Performance Degradation
|
|
3491, 3492H thru 3498H..................... |
10 mW cw or peak
|
|
3491H.................................................... |
1 mW cw or peak
|
|
All other units........................................ |
100 mW cw or peak |
|
|
|
Survival Power |
|
from -40°C to +25°C;
(see Figure 2 for Higher Temperatures)........ |
1W average, 25W peak (1 µsec max pulse width) |
|
|
|
|
|
|
|
|
Switching Time |
|
|
349(X)H-64.............................................. |
300 nsec max. |
|
349(X)-64................................................ |
550 nsec max. |
|
349(X)-80................................................ |
2 μsec max. |
|
|
|
Programming.................................................................
|
Positive true binary (standard) or BCD (Option 1). For complementary code, specify Option 2.
|
|
Minimum Attenuation Step(5)........................... |
0.25 dB |
|
Binary Units |
|
|
349(X)-64, 349(X)H-64.......................... |
0.03 dB |
|
349(X)-80............................................... |
0.04 dB |
|
BCD Units...................................................... |
0.10 dB |
|
|
|
Logic Input |
|
Logic "0" (Bit OFF)......................................... |
-0.3 to +0.8V |
|
Logic "1" (Bit ON)........................................... |
+2.0 to +5.0V |
|
Logic Input Sink Current............................... |
0.3 mA max |
|
Logic Input Source Current........................... |
3 µA max |
|
|
|
Analog Input (6) |
|
349(X)-64, 349(X)H-64................................ |
0 to 6.4V(7) |
|
349(X)-80..................................................... |
0 to 8V(8) |
|
Input Resistance............................................ |
10K ± 20% Ohms |
|
|
|
Power Supply Requirements.........................................
|
+12 to +15V, 120mA |
|
|
-12 to -15V, 50mA |
|
|
|
Power Supply Requirements.......................................... |
1. Less than 0.1 dB/volt change in either supply |
|
2. Prior to applying the supply voltages, all the command bits (including the Latch bit) should be set to "0" logical level |
NOTES |
|
|
(1) Applicable only to 80 dB versions.
(2) Specifications for the extended frequency ranges are typical.
(3) Except from 16-18 GHz where insertion loss is 4.2 dB max. and VSWR is 2.2.
(4) Flatness specification at 64 dB level is ±0.2 dB higher than at 60 dB.
(5) The Series 349 attenuators are 11-bit digital attenuators. In order to use this device with a lesser number of bits (lower resolution), the user may simply ground the logic pins for the lowest order unused bits. For example, a Series 349 unit operated as an 8-bit unit would have Pin 15, Pin 1 and Pin 2 connected to ground. All other parameters remain unchanged.
(6) Switching speed for analog input is 100 µsec. typical. With Option G06 it is not greater than with digital input.
(7) For average attenuation of 64 dB the analog voltage is in the range of 4 to 8 V.
(8) For average attenuation of 80 dB the analog voltage is in the range of 6 to 10 V.
OPTION (G09) ENVIRONMENTAL RATINGS
Operating Temperature Range............ |
-40°C to +85°C
|
Non-Operating Temperature Range.... |
-54°C to +100°C |
Humidity............................................... |
MIL-STD-202F, Method 103B, Cond. B (96 hrs. at 95%) |
Shock .... .............................................
|
MIL-STD-202F, Method 213B, Cond. B (75G, 6 msec) |
Vibration ............................................ |
MIL-STD-202F, Method 204D, Cond. B (.06" double amplitude or 15G, whichever is less)
|
Altitude .............................................. |
MIL-STD-202F, Method 105C, Cond. B (50,000 ft.) |
Temp. Cycling.................................... |
MIL-STD-202F, Method 107D, Cond. A, 5 cycles |
|
ACCESSORY FURNISHED
|
Mating power/logic connector
|
|
AVAILABLE OPTIONS
|
Option No. |
Description |
1
|
BDC programming (Binary is standard)
|
2
|
Complementary programming (logic “0” is Bit ON) |
4
|
Strobe latch for data input. Attenuator responds to data input when logic “0” is applied. Attenuator latched to data input when logic “1” is applied. See Fig. 3
|
G06 |
Switching speed for analog input is no longer than with a digital input
|
7 |
Two SMA male RF connectors
|
10 |
One SMA male RF connector (J1) and one SMA female RF connector (J2) |
G09 |
Meeting the specified Environmental Ratings |
G10 |
Glitch free driver. Recommended option. See Application Notes for Microwave Attenuators for more information |
G12 |
RoHS Compliant |
G16 |
RoHS & REACH Compliant
|
G18 |
REACH Compliant
|
|
|
DIMENSIONS AND WEIGHT
NOTES
(1) The Series 349 attenuators are 11-bit digital attenuators. In order to use this device with a lesser number of bits (lower resolution), the user may simply ground the logic pins for the lowest order unused bits. For example, a Series 349 unit operated as an 8-bit unit would have Pin 15, Pin 1 and Pin 2 connected to ground. All other parameters remain unchanged.
(2) Normally supplied as an Analog input. Leave pin open if analog input is not used. Optionally available as a strobe latch function for input data.
(3) Pin 3 is available to apply a current or voltage to control the attenuator in a non-linear fashion.
(4) lt is recommended that when operating the Series 349/H Attenuators with the Strobe/Latch Option -4 feature, the digital control inputs should be in place, with the Latch set to a low “0” level, before the Attenuator is powered up.
(5) For Model 3494-80-D69, J3 PIN 13 is +15V±5% and PIN 14 is -5V±5%.