Digital Step Attenuator 50 DC-2400 MHz 31 dB, 1 dB Step, 5 Bit, Serial Control Interface, Single Supply Voltage Product Features * Low Insertion Loss * High IP3, +52 dBm Typ * Excellent return loss, 20 dB Typ * Excellent accuracy, 0.1 dB Typ * Single Supply Voltage: +3V * Control inputs buffered by Schmitt Triggers * Rigid unibody case * Protected by US patent 6,790,049 ZX76-31-SP+ ZX76-31-SP Typical Applications * Lab * Instrumentation * Test equipment CASE STYLE: HK1172 Connectors SMA SMA Order P/N ZX76-31-SP-S+ ZX76-31-SP-S Price $73.95 ea. $73.95 ea. Qty. (1-9) (1-9) + RoHS compliant in accordance with EU Directive (2002/95/EC) The +Suffix identifies RoHS Compliance. See our web site for RoHS Compliance methodologies and qualifications. General Description The ZX76-31-SP(+) is a 507 RF digital step attenuator that offers an attenuation range up to 31 dB in 1.0 dB steps. The control is a 5-bit serial interface. The model operates on a single +3 volt supply. See application note AN-70-004 for 5V supply voltage. The ZX76-31-SP(+) is produced using a unique case package for ruggedness and operation in tough environments. Simplified Schematic RF Input 16dB 4dB 8dB 1dB 2dB RF Out Digital Serial Control REV. A M107233 '. )''#$/&-')# . ')+"$()')%&*(**!'(("& '&$"&*"&""),"+*-*"+ ZX76-31-SP EDR-7814 071031 Page Page 11 ofof 1111 ZX76-31-SP+ ZX76-31-SP Digital Step Attenuator RF Electrical Specifications, DC-2400 MHz, TAMB=25C, VDD=+3V Parameter Freq. Range (GHz) Min. Typ. DC-1 -- 0.02 0.1 dB 1-2.4 -- 0.05 0.15 dB DC-1 -- 0.05 0.15 dB 1-2.4 -- 0.15 0.25 dB DC-1 -- 0.07 0.2 dB 1-2.4 -- 0.15 0.25 dB DC-1 -- 0.03 0.2 dB 1-2.4 -- 0.15 0.3 dB DC-1 -- 0.1 0.3 dB Max. Units Accuracy @ 1 dB Attenuation Setting Accuracy @ 2 dB Attenuation Setting Accuracy @ 4 dB Attenuation Setting Accuracy @ 8 dB Attenuation Setting Accuracy @ 16 dB Attenuation Setting 1-2.4 -- 0.15 0.5 dB DC-1 -- 1.5 2.2 dB 1-2.4 -- 2.0 3.0 dB IP3 Input* (at Min. and Max. Attenuation) DC-2.4 -- +52 -- dBm Input Power @ 0.2dB Compression* (at Min. and Max. Attenuation) DC-2.4 -- +24 -- dBm DC-1 -- 1.2 1.5 -- 1-2.4 -- 1.2 1.5 -- Insertion Loss @ all attenuator set to 0dB VSWR * IP3 and 1dB compression degrade below 1 MHz DC Electrical Specifications Parameter Min. Typ. Max. Units VDD, Supply Voltage 2.7 3 3.3 V IDD,Supply Current -- -- 1.5 mA Control Input Voltage Low 0 -- 0.3xVDD V Control Input Voltage High 0.7xVDD -- 5V V -- -- 400 MA Control Current Switching Specifications Parameter Min. Typ. Max. Units Switching Speed, 50% Control to 0.5dB of Attenuation Value -- 1.0 -- MSec Switching Control Frequency -- -- 25 KHz Absolute Maximum Ratings Parameter Ratings Operating Temperature -40C to 85C Storage Temperature -55C to 100C VDD, Supply Voltage -0.3V Min., 4V Max. Voltage on Control Input -0.3V Min., 6V Max. ESD, HBM 500V ESD, MM 100V Input Power +24dBm '. )''#$/&-')# . ')+"$()')%&*(**!'(("& '&$"&*"&""),"+*-*"+ Page 2 of 11 ZX76-31-SP+ ZX76-31-SP Digital Step Attenuator Pin Description Function N/C Pin Configuration Pin Number J1-1 Description TOP VIEW J2 Not Connected GND J1-2 Ground connection LE J1-3 Latch Enable Input N/C J1-4 Not Connected GND J1-5 Ground connection P1 P2 J3 RF IN RF OUT GND +VDD N/C J1-6 Not Connected Clock J1-7 Serial Interface clock Input GND J1-8 Ground connection Data J1-9 Serial Interface data Input N/C J1-10 Not Connected RF in J2 SIDE VIEW J2 J1 J3 RF in port (Note 1) RF out J3 RF out port (Note 1) GND P1 Ground connection VDD P2 Positive Supply Voltage Note 1: Both RF ports must be held at 0VDC or DC blocked with an external series capacitor. J4 J1 J1-1 J1-10 Cable Pin Description J1-Pin Number J4-Pin Number Function J1-2 J4-18 GND Ground connection BLACK GREEN Description Wire Color J1-3 J4-4 LE Latch Enable Input J1-5 J4-19 GND Ground connection BLUE J1-7 J4-2 Clock Serial Interface clock Input RED J1-8 J4-20 GND Ground connection ORANGE J1-9 J4-3 Data Serial Interface data Input WHITE Note: Other pins not connected. Cable shield connected to case ground. '. )''#$/&-')# . ')+"$()')%&*(**!'(("& '&$"&*"&""),"+*-*"+ Page 3 of 11 ZX76-31-SP+ ZX76-31-SP Digital Step Attenuator Typical Performance Curves INSERTION LOSS (Ref) ATTENUATION (1 dB) 5.0 1.4 -40C +25C +85C 4.0 -40C +25C +85C 1.2 ATTENUATION (dB) INSERTION LOSS (dB) 4.5 3.5 3.0 2.5 2.0 1.5 1.0 1.0 0.8 0.6 0.4 0.2 0.5 0.0 0.0 0 500 1000 1500 2000 2500 3000 3500 4000 0 1500 2000 2500 3000 FREQUENCY (MHz) ATTENUATION (2 dB) ATTENUATION (4 dB) 3500 4000 3500 4000 3500 4000 4.6 -40C +25C +85C -40C +25C +85C 4.4 ATTENUATION (dB) 2.4 ATTENUATION (dB) 1000 FREQUENCY (MHz) 2.6 2.2 2.0 1.8 1.6 1.4 1.2 4.2 4.0 3.8 3.6 3.4 3.2 1.0 3.0 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 FREQUENCY (MHz) FREQUENCY (MHz) ATTENUATION (8 dB) ATTENUATION (16 dB) 17.0 8.6 -40C +25C +85C -40C +25C +85C 16.5 ATTENUATION (dB) 8.4 ATTENUATION (dB) 500 8.2 8.0 7.8 7.6 7.4 16.0 15.5 15.0 14.5 7.2 7.0 14.0 0 500 1000 1500 2000 2500 3000 3500 0 4000 500 1000 FREQUENCY (MHz) 1500 2000 2500 3000 FREQUENCY (MHz) '. )''#$/&-')# . ')+"$()')%&*(**!'(("& '&$"&*"&""),"+*-*"+ Page 4 of 11 ZX76-31-SP+ ZX76-31-SP Digital Step Attenuator Typical Performance Curves ATTENUATION (31 dB) 34 -40C +25C +85C ATTENUATION (dB) 32 30 28 26 24 22 20 0 500 1000 1500 2000 2500 3000 3500 4000 FREQUENCY (MHz) RETURN LOSS IN (Ref) RETURN LOSS OUT (Ref) 30 30 -40C +25C +85C -40C +25C +85C 25 RETURN LOSS (dB) RETURN LOSS (dB) 25 20 15 10 5 20 15 10 5 0 0 0 500 70 1000 1500 2000 2500 3000 3500 4000 0 500 1000 1500 2000 2500 3000 FREQUENCY (MHz) RETURN LOSS IN (Major Atten. Steps) @ +25oC RETURN LOSS OUT (Major Atten. Steps) @ +25oC 70 0 dB 60 2 dB 4 dB 50 8 dB 16 dB 40 4000 0 dB 1 dB RETURN LOSS (dB) RETURN LOSS (dB) 3500 FREQUENCY (MHz) 31 dB 30 20 60 1 dB 50 4 dB 2 dB 8 dB 16 dB 40 31 dB 30 20 10 10 0 500 1000 1500 2000 2500 3000 3500 4000 0 500 1000 FREQUENCY (MHz) 1500 2000 2500 3000 3500 4000 FREQUENCY (MHz) '. )''#$/&-')# . ')+"$()')%&*(**!'(("& '&$"&*"&""),"+*-*"+ Page 5 of 11 ZX76-31-SP+ ZX76-31-SP Digital Step Attenuator Typical Performance Curves IP3 (Major Atten. Steps) @ +25oC 80 COMPRESSION @ INPUT POWER=+24dBm (Major Atten. Steps) @ +25oC 0.2 0 dB 75 4 dB 8 dB 65 16 dB 60 31 dB 55 50 45 COMPRESSION (dB) 2 dB 70 IP3 (dBm) 0.1 1 dB 40 0.0 -0.1 -0.2 -0.3 0 dB 1 dB 2 dB 4 dB 8 dB 16 dB 31 dB -0.4 -0.5 -0.6 -0.7 35 -0.8 0 400 800 1200 1600 2000 2400 0 400 800 FREQUENCY (MHz) 1200 1600 2000 2400 FREQUENCY (MHz) IP3 (Major Atten. Steps) @ -40oC 80 COMPRESSION @ INPUT POWER=+24dBm (Major Atten. Steps) @ -40oC 0.2 0 dB 75 4 dB 8 dB 65 16 dB 60 31 dB 55 50 45 COMPRESSION (dB) 70 IP3 (dBm) 0.1 1 dB 2 dB 40 0.0 -0.1 -0.2 -0.3 0 dB 1 dB 2 dB 4 dB 8 dB 16 dB 31 dB -0.4 -0.5 -0.6 -0.7 35 -0.8 0 400 800 1200 1600 2000 2400 0 400 800 FREQUENCY (MHz) 1200 1600 2000 2400 FREQUENCY (MHz) IP3 (Major Atten. Steps) @ +85oC 80 COMPRESSION @ INPUT POWER=+24dBm (Major Atten. Steps) @ +85oC 0.2 0 dB 75 4 dB 8 dB 65 16 dB 60 31 dB 55 50 45 COMPRESSION (dB) 70 IP3 (dBm) 0.1 1 dB 2 dB 40 0.0 -0.1 -0.2 -0.3 0 dB 1 dB 2 dB 4 dB 8 dB 16 dB 31 dB -0.4 -0.5 -0.6 -0.7 35 -0.8 0 400 800 1200 1600 2000 2400 0 400 800 FREQUENCY (MHz) 1200 1600 2000 2400 FREQUENCY (MHz) '. )''#$/&-')# . ')+"$()')%&*(**!'(("& '&$"&*"&""),"+*-*"+ Page 6 of 11 ZX76-31-SP+ ZX76-31-SP Digital Step Attenuator Outline Drawing Outline Dimensions (inch mm ) A B C D E F G H J K L M N P Q R S 1.20 .75 .46 1.18 .04 .17 .45 .59 .33 .21 .22 .18 1.00 .50 .35 .18 .09 30.5 19.1 11.6 30.0 1.0 4.3 11.4 14.9 8.3 5.3 5.6 4.6 25.4 12.7 8.9 4.6 2.3 WT. GRAMS 35 Recommended Mounting Hardware: Use UNC#2 pan head screws with internal tooth lock washers for unit mounting. '. )''#$/&-')# . ')+"$()')%&*(**!'(("& '&$"&*"&""),"+*-*"+ Page 7 of 11 ZX76-31-SP+ ZX76-31-SP Digital Step Attenuator Simplified Schematic RF Input 16dB 8dB 4dB 2dB 1dB RF Out Digital Serial Control The ZX76-31-SP(+) Serial interface consists of 5 control bits that select the desired attenuation state, as shown in Table 1: Truth Table Table 1. Truth Table Attenuation State C16 C8 C4 C2 C1 Reference 0 0 0 0 0 1 (dB) 0 0 0 0 1 2 (dB) 0 0 0 1 0 4 (dB) 0 0 1 0 0 8 (dB) 0 1 0 0 0 16 (dB) 1 0 0 0 0 31 (dB) 1 1 1 1 1 Note: Not all 32 possible combinations of C1 - C16 are shown in table The serial interface is a 5-bit serial in, parallel-out shift register buffered by a transparent latch. It is controlled by three CMOS-compatible signals: Data, Clock, and Latch Enable (LE). The Data and Clock inputs allow data to be serially entered into the shift register, a process that is independent of the state of the LE input. The LE input controls the latch. When LE is HIGH, the latch is transparent and the contents of the serial shift register control the attenuator. When LE is brought LOW, data in the shift register is latched. The shift register should be loaded while LE is held LOW to prevent the attenuator value from changing as data is entered. The LE input should then be toggled HIGH and brought LOW again, latching the new data. The timing for this operation is defined by Figure 1 (Serial Interface Timing Diagram) and Table 2 (Serial Interface AC Characteristics). Control cables for programming and CD with software can be ordered separately. For details see page 10. Table 2. Serial Interface AC Characteristics Symbol Figure 1: Serial Interface Timing Diagram Clock Data MSB LSB tLESUP tLEPW Max. Units 10 MHz tclkH Serial clock HIGH time 30 ns tclkL Serial clock LOW time 30 ns tLESUP LE set-up time after last clock falling edge 10 ns tLEPW LE minimum pulse width 30 ns Serial data set-up time before clock rising edge 10 ns tSDSUP tSDSUP tSDHLD Min. Serial data clock frequency (Note 1) fclk LE Parameter Serial data hold time 10 ns after clock falling edge Note 1. fclk verified during the functional pattern test. Serial programming sections of the functional pattern are clocked at 10MHz to verify fclk specification. tSDHLD '. )''#$/&-')# . ')+"$()')%&*(**!'(("& '&$"&*"&""),"+*-*"+ Page 8 of 11 ZX76-31-SP+ ZX76-31-SP Digital Step Attenuator The ZX76-31-SP(+), uses a common 5-bit serial word format, as shown in Table 3: 5-Bit attenuator Serial Programming Register Map. The first bit, the MSB, corresponds to the 16-dB Step and the B1 bit corresponds to the 1 dB step. Table 3. 5-Bit attenuator Serial Programming Register Map B5 B4 B3 B2 B1 B0 C16 C8 C4 C2 C1 0 MSB (first in) LSB (last in) Note: The stop bit (B0) must always be low to prevent the attenuator from entering an unknown state. '. )''#$/&-')# . ')+"$()')%&*(**!'(("& '&$"&*"&""),"+*-*"+ Page 9 of 11 ZX76-31-SP+ ZX76-31-SP Digital Step Attenuator Recommended Accessories Two optional cable accessories with and without interface connector are available with ZX76-31-SP(+), the ZX76-CS+ and ZX76-WS+. ZX76-CS+ shielded cable with interface 25 pin D-type connector J4 and supplied software are used to control the ZX76-31-SP(+) digital attenuator from a computer, using LPT port. ZX76-WS+ shielded cable without interface 25 pin D-type connector enables customer to use the ZX76-31-SP(+) digital attenuator in his own application. Cable length is 4.9 feet / 1.5 meters. Note: Mini-Circuits can supply control cables with other options for the J4 connector and/or different cable lengths. Consult factory with your specific requirements. ZX76-CS+ Control Cable J4 J1 ZX76-CS+ wiring information J1-Pin Number J4-Pin Number Function J1-2 J4-18 GND Ground connection BLACK J1-3 J4-4 LE Latch Enable Input GREEN J1-5 J4-19 GND Ground connection BLUE J1-7 J4-2 Clock Serial Interface clock Input RED J1-8 J4-20 GND Ground connection ORANGE J1-9 J4-3 Data Serial Interface data Input WHITE Description Wire Color Note: Other pins not connected. Cable shield connected to case ground. '. )''#$/&-')# . ')+"$()')%&*(**!'(("& '&$"&*"&""),"+*-*"+ Page 10 of 11 ZX76-31-SP+ ZX76-31-SP Digital Step Attenuator ZX76-WS+ Control Cable J1 ZX76-WS+ wiring information J1-Pin Number Function J1-2 GND Ground connection J1-3 LE Latch Enable Input GREEN J1-5 GND Ground connection BLUE J1-7 Clock Serial Interface clock Input RED J1-8 GND Ground connection ORANGE J1-9 Data Serial Interface data Input WHITE Description Wire Color BLACK Note: Other pins not connected. Cable shield connected to case ground. Ordering Information Model Number Description Quantity Min. No. of Units Price $ Ea. 1-9 73.95 22.95 ZX76-31-SP-S (+) Digital attenuator - Serial interface Single Positive Supply Voltage ZX76-CS+ Cable accessory with interface connector 1 ZX76-WS+ Cable accessory without interface connector 1 15.95 ZX76-CD* CD ROM ZX76 programming software 1 No Charge *Note: To receive the CD, request when placing order. '. )''#$/&-')# . ')+"$()')%&*(**!'(("& '&$"&*"&""),"+*-*"+ Page 11 of 11