GHz 6-Bit Digital Attenuator

Transcription

1 GHz 6-Bit Digital Attenuator Features Frequency Range :.5 to 1.5 GHz 31.5dB Attenuation Range 5.2dB Insertion loss max..5db RMS attenuation error 23 max. phase variation 1.6:1 Input\Output VSWR TTL Control Inputs.5µm InGaAs phemt Technology Chip Size : 4. mm x 2.2 mm x.1 mm RF Functional Diagram.5dB 1dB 2dB 4dB 8dB 16dB RF TTL A1 A2 A A4 A A6 +5 GND Typical Applications Radar Military & Space Instrumentation Test and Measurements Instrumentation Applications Description The AMT is a high performance 6-bit digital attenuator MMIC offering an attenuation range of 31.5dB in steps.5db. The attenuator bit values are.5db (LSB), 1,2,4,8 and 16dB (MSB) with a total attenuation of 31.5dB. The attenuator features good attenuation accuracy of +.5dB over.5-6ghz frequency band. The attenuator provides an integral TTL driver, facilitating a 6-bit control. The driver operates on +5/V voltages with minimal DC power consumption. The MMIC die is fabricated using a robust.5µm InGaAs phemt technology. Absolute Maximum Ratings (1) Parameter Absolute Maximum Units RF Input Power 2 dbm Positive Supply Voltage +6 V Negative Supply Voltage -6 V Control Voltage -.5 to +5.5 V Operating Temperature 5 to +85 ºC Storage Temperature -65 to +15 ºC 1. Operation beyond these limits may cause permanent damage to the component Page 1 of 11

2 Electrical Specifications T A = 25 o C, Z o =5 Ω Parameter Value Units Attenuation Range db Attenuation step db Insertion Loss (max) Attenuation Accuracy over 64 states ±.2 +1% of Att. setting max. ±.4 +3% of Att. setting max. Phase variation over 64 states deg RMS Error <.25 <.5 Input/Output VSWR :1 DC Bias Voltages - +5, V Control Voltage - / +5 V db db db Note: 1. Electrical specifications as measured on Wafer. Page 2 of 11

3 On Wafer data T A = 25 o C Insertion Loss -1-2 IL(dB) Normalised Attenuation 35 Attenuation (db) Page 3 of 11

4 On Wafer data T A = 25 o C 1.5 Attenuation Error 1. Attn error(db) Attenuation Error 1. Attn error(db) States Page 4 of 11

5 On Wafer data T A = 25 o C 5 Phase Error Phase error(deg) Phase Error Phase error(deg) States Page 5 of 11

6 On Wafer data T A = 25 o C Port 1 Return Loss -1 RL(dB) Port2 Return Loss -1 RL(dB) Page 6 of 11

7 On Wafer data T A = 25 o C 1. RMS Error RMS Error (db) Page 7 of 11

8 Truth Table State Attenuation TTL Control ( 1 = 3.5 to 5 V, = to.5 V ) (db) A6 (16) A5 (8) A4(4) A3 (2) A2(1) A1 (.5) Page 8 of 11

9 Truth Table State Attenuation TTL Control ( 1 = 3.5 to 5 V, = to.5 V ) (db) A6 (16) A5 (8) A4(4) A3 (2) A2(1) A1 (.5) Page 9 of 11

10 Mechanical Characteristics 1.91 [.75] 1.76 [.69] 1.61 [.63] V +5V RF RF.19 [.7].34 [.13].49 [.19] A1 A2 A3 A4 A5 A6 +5V V 1.4 [.41] 1.24 [.49] 1.44 [.57] 1.63 [.64] 1.84 [.72] 2.4 [.8] 2.66 [.15] 2.96 [.117] 4. [.158].33 [.13].48 [.19] 2.2 [.87] Units: millimeters (inches) Note: 1. All RF and DC bond pads are 1µm x 1µm 2. Pad no.1: RF port 1 3. Pad no.2: Optional V 4. Pad no.3: Optional +5V 5. Pad no.4: RF port 2 6. Pad no.5: V 7. Pad no.6: +5V 8. Pad nos.7-12: Control pads; Pad 7: MSB(16dB) & Pad 12: LSB (.5dB) Page 1 of 11

11 Recommended Assembly Diagram 5 Ohm Transmission Line 5 Ohm Transmission Line V +5V RF RF 1 mil gold wire 3 mil nominal gap A1 A2 A3 A4 A5 A6 +5V V DC Control Voltage +5V V Note: 1. Both the RF ports are DC coupled 2. No external components are required for this chip Die attach: For Epoxy attachment, use of a two-component conductive epoxy is recommended. An epoxy fillet should be visible around the total die periphery. If Eutectic attachment is preferred, use of fluxless AuSn (8/2) 1-2 mil thick preform solder is recommended. Use of AuGe preform should be strictly avoided. Wire bonding: For DC pad connections use either ball or wedge bonds. For best RF performance, use of 15-2µm length of wedge bonds is advised. Single Ball bonds of 25-3µm though acceptable, may cause a deviation in RF performance. GaAs MMIC devices are susceptible to Electrostatic discharge. Proper precautions should be observed during handling, assembly & testing All information and Specifications are subject to change without prior notice Page 11 of 11