OPERATING MANUAL DIGITALLY CONTROLLED FREQUENCY SYNTHESIZED OSCILLATOR MODEL NUMBER: DOCUMENT NUMBER: 51A19937C For More Information, Contact: sales@goochandhousego.com www.goochandhousego.com As part of our policy of continuous product improvement we reserve the right to change specifications at any time. 51A19937C 1 OF 14 58A23221
a Gooch and Housego Company TABLE OF CONTENTS Section Title Page I INSPECTION PROCEDURE 3 II GENERAL DESCRIPTION 4 III SPECIFICATION 5 IV OUTLINE DRAWING 6 V CONTROLS AND CONNECTIONS 7 VI CONTROL WORD CALCULATION 10 VII CIRCUIT DESCRIPTION 11 VIII TIMING DIAGRAM 12 IX OPERATING PROCEDURE 13 2 OF 14
SECTION I INSPECTION a Gooch and Housego Company Examine the shipping carton for damage. If the shipping carton or packing material is damaged it should be kept for the carrier s inspection.. Notify the carrier and Gooch & Housego. Check the contents of the shipment for completeness, mechanical damage, and then test the equipment electronically. Operating procedures are contained in Section IX. If the contents are incomplete, or the equipment does not pass the electrical testing please notify Gooch & Housego. If there is any problem with the use of this equipment, or if the equipment fails to function as expected contact Gooch & Housego, do not try to trouble shoot or repair this equipment. Consult with a Gooch & Housego service engineer. If the equipment needs repair or replacement, contact Gooch & Housego, Inc for a Return Authorization Number. 3 OF 14
SECTION II GENERAL DESCRIPTION a Gooch and Housego Company The is a digitally controlled frequency synthesized oscillator. It is designed to supply a RF output of up to two Watts of RF energy into an Acousto-Optic Beam Deflector (AOBD) or a 50 ohm load. The system requires 100 to 240VAC power input; A TTL level, 30 bit binary word to set the frequency for the synthesizer; and an selectable analog voltage input through "MOD IN" analog for operation. The analog input is selectable between 0 to +1 Volt analog input for modulation or a fixed output power level set internally. There also is a test point output a frequency reference signal from the oscillator that is 0 dbm nominal. See the driver Acceptance Test Report for performance data. The RF power level control "MOD IN" signal can be input through a BNC connector, when the front panel "NORMAL"/"CW" control switch is in the "NORMAL" position. With the switch in the "CW" position, the "MOD IN" signal for the oscillator is set to +1 VDC (full power output). There is also a HEX code input switch on the front panel for the oscillator that can be used to set the frequency of the synthesizer when the "MANUAL"/"AUTO" front panel switch is set to "MANUAL" position. This switch, when set to "AUTO" position, allows the input from the 37 pin D sub connector of the "FREQUENCY SELECT" digital 30 bit binary word signal for the synthesizer. The "Frequency Select" digital 30 bit binary word signal is input through a 37 pin D sub connector to the synthesizer. In addition to the 30 "Frequency Select" data input lines, there are three other control lines: The Latch function is used to keep the current output frequency from changing while a new input word is being generated. For best operation, the new word should be formed while the latch is HIGH, the latch signal brought Low for 50 ns to load in the data, and then returned to the HIGH state. The latch function requires a falling edge. The Digital Modulation function disables the output of the driver. This function requires a TTL low as the input is pulled high internally via a 4.7 k resistor. The Reset is used to disable the output of the driver and clear the stored frequency information. This function requires a TTL high as the input is pulled LOW via. a 1 k resistor. 4 OF 14
SECTION III SPECIFICATION a Gooch and Housego Company PARAMETER SPECIFICATION Number of synthesizers 1 Bandwidth Clock Frequency Step Size Power Out Rise and Fall Time Harmonic Distortion 2nd 3rd Extinction Ratio Output Impedance Applied Power Digital Analog 20-200MHz typical 1000 MHz <1 Hz with 30 Bits input 2 watts typical 20ns <-20dB <-15dB 30 db 40 db 50 Nominal 100 to 240 VAC @ 1.5 Amps max. 50 to 60Hz External Modulation ("MOD IN") "FREQUENCY SELECT" Control "TEST POINT" Output X2 "CW / NORMAL" Switch "MANUAL / AUTO" Switch LATCH SWITCH Dimensions Mounting holes Package 0 to +1 volt Analog, +1 volt = full RF power output. TTL 30 bit binary word, ENABLE, RESET, and a LATCH control input through the 37 pin D sub connector. See page 8 for pinout. 0 dbm nominal. CW = RF on. Set point = 2 watts output NORMAL = RF controlled from "MOD IN" port 0 to 1 volt Analog 1, volt = full RF output. MANUAL = frequency set from HEX switch AUTO = frequency set from "FREQUENCY SELECT" 37 pin D sub connector. Toggle to latch in a new frequency. 3.45 X 19.0 X 10.4 inches maximum 1.75 X 18.32 inches 53D2400 5 OF 14
SECTION IV OUTLINE DRAWING a Gooch and Housego Company 6 OF 14
a Gooch and Housego Company 53D2400 SECTION V CONTROLS AND CONNECTIONS BACK PANEL: A. "RF OUT" The output of the driver supplies two Watts of RF energy OUTPUT SMA into the Acousto-Optical Beam Deflector or 50 ohms. B. "MOD IN" This port accepts an analog modulation voltage between INPUT BNC 0 and +1volt when the front panel switch is set to "NORMAL" +1 volt is full RF output. C. "TEST POINT " This port output a reference signal the RF OUTPUT level. OUTPUT SMB @ 0 dbm nominal D. "FREQUENCY SELECT" This port accepts a 30 bit TTL word to set the frequency of the 37 PIN SUB D oscillator when the front panel switch is in the "AUTO" position. CONNECTOR Also DIGITAL, RESET, and a LATCH control input. See page 8 for pinout. E. AC POWER INPUT 100 to 240VAC 50 to 60 Hz. CONNECTOR F. FUSE AG 1.5 amp 250 volt fuse. 7 OF 14
a Gooch and Housego Company FRONT PANEL: G. POWER SWITCH Applies AC power to the system. H. HEX SWITCH HEX word input for the frequency output for each oscillator. I. "CW / NORMAL" "CW" Position: The RF output power is set to full on. MODE SWITCH "NORMAL" Position: The output follows the "MOD IN" voltage to set the output power. J. MANUAL / AUTO" "MANUAL" Position: The frequency is set by the HEX switch MODE SWITCH on the front panel. You must use the reset switch to load the new frequency. "AUTO" Position: The frequency is set by the TTL level 30 bit word input through the 37 pin D sub connector on the back panel. The ENABLE control is available regardless of switch position. The RESET and LATCH control are disabled in MANUAL Position. K. RESET Switch In "MANUAL" Position: The reset switch, when toggled, latches in the setting of the front panel Hex code switches into the synthesizer to output the new frequency setting. INTERNAL MODULE: L. MAXIMUM RF OUTPUT POWER LEVEL ADJUSTMENT POT 8 OF 14
a Gooch and Housego Company SYNTHESIZER 64XXX-XXX-2ADSDFS-A "FREQUENCY SELECT" PIN OUT 37-PIN MALE D-SUB CONNECTOR PIN PIN 1 FS 0 LSB 20 FS 1 2 FS 2 21 FS 3 3 FS 4 22 FS 5 4 FS 6 23 FS 7 5 FS 8 24 FS 9 6 FS 10 25 FS 11 7 FS 12 26 FS 13 8 FS 14 27 FS 15 9 FS 16 28 FS 17 10 FS 18 29 FS 19 11 FS 20 30 FS 21 12 FS 22 31 FS 23 13 FS 24 32 FS 25 14 FS 26 33 FS 27 15 FS 28 34 FS 29 MSB 16 Latch 35 Digital Modulation, Active High 17 Master Reset, Active High 36 N/C 18 N/C 37 N/C 19 Ground Control Word K 10 31 FOUT (Hz)(2 ) in Decimal notation FOSC (Hz) 9 OF 14
SECTION VI CONTROL WORD CALCULATIONS a Gooch and Housego Company The output frequency and step size is a function of the clock rate and the "FREQUENCY SELECT" data. The output frequency can be calculated from the formula: (fc) (k10) fout n 2 Where: f c = clock frequency in Hz k 10 = input word in decimal notation n = 31 *See note below. The minimum output frequency and step size are given by: fc fmin n 2 An example of setting the frequency: Clock frequency = 1000 x 10 6 Hz Desired output frequency = 30.00 x 10 6 Hz K 10 f OUT (Hz) f (2 OSC (Hz) 31 ) K 10 6 30 x 10 (2 6 (1000 x 10 31 ) ) Convert K10 K10 64424509.44 Decimal to HEX K HEX = 3D70A3D -Setting for front panel "HEX" switches Convert K HEX to Binary \/ LSB - pin1 K B = 000011110101110000101000111101 -Setting for binary word input to back panel "FREQUENCY SELECT" 37 pin D-sub connector *Note: This system only uses 30 bits to set the frequency output from the driver. The accumulator inside the chip is 31 bit, so use 2 31 in your calculations for precision. The LATCH function (pin 16) is a TTL compatible input which is used to load new frequency information into the driver. Frequency data is loaded into the driver when the signal on the LATCH pin goes from HIGH to LOW (falling edge). The DIGITAL MODULATION function is pulled high internally via a 4.7 k resistor. The function disables the output of the driver when a TTL low is applied on pin 35. Master RESET is a TTL active HIGH and resets the accumulator to zero, ie, no frequency output, When a TTL HIGH is applied to pin 17. This is pulled LOW via. a 1 k resistor. 10 OF 14
SECTION VII CIRCUIT DESCRIPTION a Gooch and Housego Company The 64020-200-2ADMDFS-A is a digital frequency synthesizer consist of a DFS circuit with a 30 bit binary word "Frequency Select" input control and a 1GHz clock, a manual output power level adjustment, a Digital and Analog Mod in input to control the output power level, a pre-amplifier stage, a output power amplifier stage, and a un-modulated reference signal output. In addition to the 30 "Frequency Select" data input lines, there are three other control lines. The "Latch" input is used to input a new frequency. The new frequency is moved into the dds core when a falling edge is present on the latch input. The "Digital Modulation" function disables the output of the driver when a TTL low is applied on pin 35. This function is pulled HIGH internally via a 4.7k resistor. The Reset is used to disable the output of the driver and clear the stored frequency information. This function requires a TTL high as the input is pulled LOW via. a 1 k resistor.. 11 OF 14
SECTION VIII TIMING DIAGRAM a Gooch and Housego Company 45A15240 12 OF 14
a Gooch and Housego Company SECTION VIII OPERATING PROCEDURES TESTING: A. Connect the "RF out" to a 50-ohm load capable of dissipating 2 watts. B. Connect a digital 30 bit control cable to the "FREQUENCY SELECT" port (37 pin D sub connectors). See page 9 for pin out for LSB TO MSB. Note: No signal is required on the "RESET", or "DIGITAL MODULATION" control lines to output RF. C. Connect a +1 volt DC signal for amplitude adjustment to the "MOD IN" port (BNC connector) (1VDC = full on). DO NOT EXCEED 1 volt DC. D. Connect each of the "TEST POINT" outputs to your frequency counter. E. Turn on the Power Switch. F. With the "Mode" switches in the "CW" position and "MANUAL" position, test the frequency output verses word input from the front panel HEX input switches. Toggle the latch switch to latch the new frequency set by the HEX input switches. G. With the HEX switches set to the center frequency of the AOBD device, (See AOBD Acceptance Test Report), adjust the driver output power level control inside the driver box (multi- turn pot on pc board through hole.) for the power required for maximum diffraction efficiency of the AOBD device or to a power which does not exceed the maximum allowed for the AOBD device. Note: The maximum output power of the driver is pre-set at the factory to match the maximum required power for the AOBD. This adjustment is necessary only if the driver and AOBD were purchased separately. Warning: With the "Mode" switch in the "CW" position, the driver will output up to 2 Watts of RF power. Do not exceed the maximum allowed for the AOBD device or damage will occur. If damage results due to overpowering the AOBD device, the warranty will be void. H. With the "Mode" switches in the "CW" position and "AUTO" position, apply a 30 bit word to the "FREQUENCY SELECT" (37 pin D sub connectors). Test the frequency output vs. word input. I. With the "Mode" switches in the "NORMAL" position and "AUTO" position apply a 0 to +1 volt signal to the "MOD IN" port to test the output power verses analog input voltage, rise time and other parameters listed on the Acceptance Test Report. 13 OF 14
a Gooch and Housego Company OPERATION: A. Attach the AOBD device to the RF output of the driver with a 50 ohm cable. B. With the driver turned on and the "Mode" switches in the "CW" position and "AUTO" position, apply the necessary Binary word to the "FREQUENCY SELECT" port to output the center frequency for the AOBD. See AOBD Acceptance Test Report or calculate the needed Binary word. This will set the frequency to produce an output beam from the AOBD to be at the center of the optical path. C. Follow the instructions in the AOBD device manual to align and adjust the device as required in your optical system. D. With the "Mode" switches in the "CW" position and "AUTO" position, apply the necessary signals to the "FREQUENCY SELECT" port as desired. E. Apply the needed signals to the "Reset", and "Digital Modulation" control lines to control the "blanking" if needed. F. If external analog modulation or power leveling to achieve AOBD "field flatness" is required, then set the "Mode" switches to "Normal" position and "AUTO" position and apply the necessary signals to the "FREQUENCY SELECT" port as desired. Apply the needed analog signal to the "MOD IN" port as each word is input to output the needed power to compensate for AOBD "field flatness". Modulate as needed. Do not exceed the maximum allowable power for the AOBD as damage may occur. Note: It is necessary to adjust the Bragg angle of the AOBD device to the flattest field before trying to compensate for RF drive power as any change in Bragg angle will effect the diffraction efficiency of the AOBDs across the scan field. 14 OF 14