DC – 50 GHz Variable Attenuator Technical Data HMMC-1002 Features • Specified Frequency Range: DC -26.5 GHz • Return Loss: 10 dB • Minimum Attenuation: 2.0␣ dB • Maximum Attenuation: 30.0␣ dB Description The HMMC-1002 is a monolithic, voltage variable, GaAs IC attenuator that operates from DC to 50␣ GHz. It is fabricated using MWTC’s MMICB process which features an MBE epitaxial layer, backside ground vias, and FET gate lengths of approximately 0.4␣ mm. The variable resistive elements of the HMMC-1002 are two 750 mm wide series FETs and four 200 mm wide shunt FETs. The distributed topology of the HMMC-1002 minimizes the parasitic effects of its series and shunt FETs, allowing the HMMC-1002 to exhibit a wide dynamic range across its full bandwidth. An on-chip DC reference circuit may be used to maintain optimum VSWR for any attenuation setting or to improve the attenuation versus voltage linearity of the attenuator circuit. Chip Size: Chip Size Tolerance: Chip Thickness: RF Pad Dimensions: DC Pad Dimensions: 1470 x 610 µm (57.9 x 24.0 mils) ± 10 µm (± 0.4 mils) 127 ± 15 µm (5.0 ± 0.6 mils) 60 x 70 µm (2.4 x 2.8 mils), or larger 75 x 75 µm (3.0 x 3.0 mils), or larger Absolute Maximum Ratings[1] Symbol Units Min. Max. DC Voltage to RF Ports V -0.6 +1.6 V1 V1 Control Voltage V -5.0 +0.5 V2 V1 Control Voltage V -5.0 +0.5 VDC DC In/DC Out V -0.6 +1.0 Pin RF Input Power VDC-RF Parameters/Conditions dBm Tmina Minimum Ambient Operating Temperature °C Tmaxa Maximum Ambient Operating Temperature °C TSTG Storage Temperature °C Tmax Maximum Assembly Temp. °C 17 -55 +125 -65 +165 +300 Note: 1. Operation in excess of any one of these conditions may result in permanent damage to this device. 5965-5452E 7-12 DC Specifications/Physical Properties, TA = 25°C Symbol Parameters and Test Conditions Units Min. Typ. Max. I V1 V1 Control Current, (V1 = -4V) mA 5.3 9.3 12 I V2 V2 Control Current, (V2 = -4V) mA 5.3 9.3 12 Vp Pinch-off Voltage (V2, with V1 = 0 V) Four 200 µm wide shunt FETs, VDD = 1 V @ RFin, IDD = 5 mA V -0.6 -1.3 -2.5 Electrical Specifications[1], TA = 25°C, ZO = 50 Ω Parameters and Test Conditions Minimum Attenuation, |S21| Units V1 = 0 V, V2 = -4 V Input/Output Return Loss @ Min. Attenuation Setting, dB dB V1 = 0 V, V2 = -4 V Maximum Attenuation, |S21| V1 = -4 V, V2 = 0 V Freq. (GHz) Typ. Max. 1.5 1.0 2.4 8.0 1.4 2.4 20.00 1.7 2.4 26.5 2.0 2.4 50.0 3.9 <26.5 Min. 10 <50.0 dB 8 1.5 27 30 8.0 27 38 20.0 27 38 26.5 27 40 50.0 Input/Output Return Loss @ Max. Attenuation Setting, dB V1 = -4 V, V2 = 0 V DC Power Dissipation (does not include input signals) V1 = -5 V, V2 = -5 V 7-13 <26.5 <50.0 mW 16 35 8 10 10 152 Applications The HMMC-1002 is designed to be used as a gain control block in an AGC assembly. Because of its wide dynamic range and return loss performance, the HMMC-1002 may also be used as a broadband pulse modulator or single-pole single-throw, nonreflective switch. Operation The attenuation of the HMMC-1002 is adjusted by applying negative voltages to V1 and V2. V1 controls the drain-tosource resistances of the series FETs while V2 controls the drainto-source resistances of the shunt FETs. For any HMMC-1002 the values of V1 may be adjusted so that the device attenuation versus voltage is monotonic for both V1 and V2; however, this will slightly degrade the input and output return loss. The attenuation of the HMMC-1002 may also be controlled using only a single input voltage by utilizing the on-chip DC reference circuit and the driver circuit shown in Figure 4. This circuit optimizes VSWR for any attenuation setting. Because of process variations, the values of VREF, RREF, and RL are different for each wafer if optimum performance is required. Typical values for these elements are given. The ratio of the resistors R1 and R2 determines the sensitivity of the attenuation versus voltage performance of the attenuator. For more information on the performance of the HMMC-1002 and the driver circuits previously mentioned see MWTC’s Application Note #37, “HMMC-1002 Attenuator: Attenuation Control.” For more S-parameter information, see MWTC’s Application Note #44, “HMMC-1002 Attenuator: S-Parameters.” Assembly Techniques Solder die attach using a AuSn solder preform is the recommended assembly method; however, an epoxy die attach method using ABLEBOND® 71-1LM1 or ABLEBOND® 36-2 may also be employed. Gold thermosonic wedge bonding with 0.7 mil wire is the recommended method for bonding to the device. Tool force should be 22␣ grams␣ ± ␣ 1␣ gram, stage temperature is 150␣ ± ␣ 2 °C, and ultrasonic power and duration of 64 ± 1␣ dB and 76 ± 8␣ msec, respectively. The top and bottom metallization is gold. For more detailed information see HP application note #999 “GaAs MMIC Assembly and Handling Guidelines.” GaAs MMICs are ESD sensitive. Proper precautions should be used when handling these devices. RFOUT RFIN DC Reference Circuit DCIN V1 DCOUT Figure 1. HMMC-1002 Schematic. 7-14 V2 610 RF OUT RF IN 233 0 0 476 584 887 Notes: 1. All dimensions in microns and shown to center of bond pad. 2. DCin, V1, DCout, and V2 bonding pads are 75 x 75 microns. 3. RF input and output bonding pads are 60 x 70 microns. 4. Chip thickness: 127 ± 15 µm. Figure 2. HMMC-1002 Bonding Pad Locations. 2.0 mil nom. gap RFIN RFOUT TC721A 4 Wire Bonds using 0.7 mil dia. Gold Bond Wire (Length NOT important) DCIN V1 DCOUT V2 Figure 3. HMMC-1002 Assembly Diagram. 7-15 994 1410 1470 233 To DCOUT To DCIN To V1 To V2 RL (400 Ω – 500 Ω) 500 Ω Op. Amp – VREF VIN (-0.4V to -1.0V) + 500 Ω (0V to -4.0V) RREF (350 Ω – 500 Ω) Figure 4. Attenuator Driver. 0 0 10 10 RETURN LOSS (dB) INSERTION LOSS (dB) HMMC-1002 Typical Performance 20 30 40 Maximum Attenuation 20 30 40 50 50 60 1.5 4.0 60 1.5 4.0 8.0 12.0 16.0 20.0 24.0 26.5 FREQUENCY (GHz) Figure 5. Attenuation vs. Frequency[1]. Minimum Attenuation 8.0 12.0 16.0 20.0 24.0 26.5 FREQUENCY (GHz) Figure 6. Output Return Loss vs. Frequency[1]. Note: 1. Data obtained from on-wafer measurements. Tchuck = 25°C. 7-16 HMMC-1002 Typical Power Performance All Attenuation Settings were done at 1 GHz. 0 0 10 10 0 20 30 40 -5 0 5 10 15 20 30 40 -5 20 ATTENUATION (dB) ATTENUATION (dB) ATTENUATION (dB) 10 20 30 40 0 5 10 15 50 -5 20 0 5 10 15 20 INPUT POWER (dBm) INPUT POWER (dBm) INPUT POWER (dBm) Figure 7. Attenuation vs. Input Power @ 50.0 MHz.[1]. Figure 8. Attenuation vs. Input Power @ 2.0 GHz.[1]. Figure 9. Attenuation vs. Input Power @ 10.0 GHz.[1]. ATTENUATION (dB) ATTENUATION (dB) 10 20 30 40 50 -5 0 0 10 10 ATTENUATION (dB) 0 20 30 40 50 0 5 10 15 20 60 -5 20 30 40 50 0 5 10 15 20 60 -5 0 5 10 15 20 INPUT POWER (dBm) INPUT POWER (dBm) INPUT POWER (dBm) Figure 10. Attenuation vs. Input Power @ 14.0 GHz.[1]. Figure 11. Attenuation vs. Input Power @ 18.0 GHz.[1]. Figure 12. Attenuation vs. Input Power @ 22.0 GHz.[1]. Note: 1. Data taken with the device mounted in connectorized package. 7-17 Key for Attenuation Settings: Min. Min. + 5 dB Min. + 10 dB Min. + 15 dB Min. + 20 dB Min. + 30 dB Max. HMMC-1002 Typical Harmonic Performance -20 -40 -50 -60 -70 -80 -90 0 Fundamental Frequency: 50 MHz 2 GHz -30 HARMONICS (dBc) -30 HARMONICS (dBc) -20 Fundamental Frequency: 50 MHz 10 GHz 2 GHz -40 -50 -60 -70 -80 5 10 15 20 25 30 35 40 ATTENUATION (dB) Figure 13. Second Harmonic Suppression vs. Attenuation. Input Power = 0 dBm[1]. -90 0 5 10 15 20 25 30 35 40 ATTENUATION (dB) Figure 14. Third Harmonic Suppression vs. Attenuation. Input Power = 0 dBm[1]. Note: 1. Data taken with the device mounted in connectorized package. 7-18 HMMC-1002 Typical Temperature Performance 1.5 8 2 3 ATTENUATION S21 (dB) ATTENUATION S21 (dB) ATTENUATION S21 (dB) 1 3.5 5.5 7.5 9.5 4 2 6 10 14 18 22 6 Figure 15. Attenuation vs. Temperature @ Minimum Attenuation.[2]. 14 18 22 26.5 2 26 32 36 40 30 10 14 18 22 26.5 FREQUENCY (GHz) Figure 18. Attenuation vs. Temperature @ 20 dB Attenuation.[2]. 14 18 22 26.5 32 ATTENUATION S21 (dB) ATTENUATION S21 (dB) 22 10 Figure 17. Attenuation vs. Temperature @ 10 dB Attenuation.[2]. 28 6 6 FREQUENCY (GHz) Figure 16. Attenuation vs. Temperature @ 5 dB Attenuation.[2]. 18 ATTENUATION S21 (dB) 10 FREQUENCY (GHz) FREQUENCY (GHz) 2 16 20 2 26.5 12 36 40 44 48 2 6 10 14 18 22 26.5 FREQUENCY (GHz) Figure 19. Attenuation vs. Temperature @ 30 dB Attenuation.[2]. Note: 1. Data taken with the device mounted in connectorized package. This data sheet contains a variety of typical and guaranteed performance data. The information supplied should not be interpreted as a complete list of circuit specifications. In this data sheet the term typical refers to the 50th percentile performance. For additional information contact your local HP sales representative. 7-19 2 6 10 14 18 22 26.5 FREQUENCY (GHz) Figure 20. Attenuation vs. Temperature @ Max. Attenuation.[2]. Key for Temperature Settings: -55°C -25°C 0° C +25°C +55°C +85°C