GW Instek SFG-830 User Manual

Signal Function Synthesizer

Mode : SFG-830

82FG-83000MC

Contents

1. Precautions............................................................................................................1

2. Product Outline......................................................................................................4

3. Features..................................................................................................................5

4. Specifications........................................................................................................6

5. Front and Rear Panels...........................................................................................8

6. Operation..............................................................................................................11

6.1 The Setup of Output Function...................................................................11

6.2 The Setup of Frequency.............................................................................11

6.3 The Setup of Amplitude .............................................................................11

6.4 The Setup of Offset ....................................................................................12

6.5 The Setup of Arbitrary-Wave Compiler.....................................................12

6.6 Deleting the Data of Arbitrary Wave ......................................................... 13

6.7 The Setting of STOR Button......................................................................13

6.8 The Setting of RECL Button ......................................................................14

6.9 The SHIFT Key and Function Keys...........................................................14

6.10 Setup of LIN or LOG Sweep.....................................................................15

6.11 Setup of AM Modulation ..........................................................................16

6.12 Setup of FM Modulation...........................................................................17

6.13 Setup of PM Modulation...........................................................................18

6.14 The Commands of GPIB Serial Interface................................................18

6.15 Syntax and Commands:...........................................................................22

6.16 The Examples of the Communication Interface Software.....................24

7. Adjustment and Correction ................................................................................27

7.1 Preparation .................................................................................................27

7.2 Adjusting Clock..........................................................................................27

7.3 Adjusting the DC of Frequency Double....................................................27

7.4 Adjusting D/A Ref.......................................................................................27

7.5 Adjusting the Bandwidth...........................................................................27

7.6 Adjusting the Filter.....................................................................................28

7.7 Adjusting Harmonic Distortion..................................................................28

7.8 Calibrating by Software .............................................................................28

7.9 Checking Frequency Accuracy.................................................................32

7.10 Checking the Amplitude ..........................................................................32

.8. The Block Diagram and Description of the System.........................................35

Appendix 1 Commands of IEEE488.2………………………………………………..38 Appendix 2 RS-232 Wiring Configuration…………..………………………………43

EC Declaration of Conformity

GOOD WILL INSTRUMENT CO., LTD.

(1) NO. 95 - 11, Pao Chung Rd., Hsin-Tien City, Taipei Hsien, Taiwan (2) Plot 522, Lorong Perusahaan Baru 3, Prai Industrial Estate, 13600 Prai,

Penang, Malaysia declare, that the below mentioned product

SFG-830

is herewith confirmed to comply with the requirements set out in the Council Directive on the Approximation of the Law of Member States relating to Electromagnetic Compatibility (89/336/EEC,92/31/EEC,93/68/EEC) and Low Voltage Equipment Directive(73/23/EEC). For the evaluation regarding the Electromagnetic Compatibility and Low Voltage Equipment Directive, the following standards were applied:

EN50081-1: Electromagnetic compatibility -

(1992) Generic emission standard

Part 1: Residential, commercial and light

industry Conducted Emission Radiated Emission (1994) Radiated Immunity IEC 1000-4-3 (1995) Current Harmonics EN 61000-3-2 +A12 (1996) Electrical Fast

Voltage Fluctuations

------------------ ---------- ---------- Voltage Dip/Interruption EN 61000-4-11 (1994)

EN50081-2: Electromagnetic compatibility -

(1993) Generic emission standard

Part 2: Industrial Environment Conducted Emission EN 55011 class A Radiated Emission (1991)

EN 55022 class A Electrostatic Discharge IEC 1000-4-2 (1995)

EN 61000-3-3 (1995) Surge Immunity IEC 1000-4-5 (1995)

EN50082-1: Electromagnetic compatibility -

(1992) Generic immunity standard

Part 1: Residential, commercial and light industry

IEC 1000-4-4 (1995)

Transients

Low Voltage Equipment Directive 73/23/EEC

Low Voltage Directive

EN 61010-1:(1993)+A2:(1995)

SFG-830 p.1

1. Precautions

SFG-830 is especially designed for safe operation. It has passed rigorous tests of inclement environment to ensure its reliability and good condition.

The following precautions are recommended to insure your safety and the best condition of this equipment.

(1) Safety Terms and Symbols

The following terms and symbols may appear in this manual:

! !

WARNING

CAUTION

This statement identifies conditions or practices that could result in injury or loss of life.

This statement identifies conditions or practices that could result in damage to this product or other properties.

The following terms and symbols may appear on the product:

DANGER WARNING

This term indicates an immediately accessible injury hazard. This term indicates that an injury hazard may occur, but is not immediately accessible.

CAUTION

This term indicates potential damage to this product or other properties.

DANGER

High voltage

Protective

Conductor

Terminal

ATTENTION

refer to manual

Double

Insulated

DANGER

Hot surface

(2) Do not place any heavy objects on the instrument under any circumstances.

Earth

Ground

Terminal

(3) Disassembling the instrument

Due to the precision of this instrument, all the disassembling, adjusting, and maintenance should be performed by a professional technician. If the instrument have to be opened or adjusted under some unavoidable conditions, it should be carried out by a technician who is familiar with SFG-830. Once there is any abnormality, please contact our company or the agency near you.

(4) Power Supply

AC input should be within the range of line voltage±10%, 50/60Hz. To prevent the instrument from burning up, be sure to check the line voltage before turning on power.

SFG-830 p.1

(5) Grounding

To avoid electrical shock, the power cord protective grounding

WARNING

conductor must be connected to ground.

SFG-830 can be operated only with an earth grounded AC power cord that connects the case and ground well. This is to protect the user and the instrument from the risk of shock hazard.

(6) Fuse Replacement

For continued fire protection, replace fuse only with the

WARNING

specific type and rating. Disconnect the power cord before replacing fuse.

The fuse blows only if there is anything wrong with the instrument, and SFG-830 will stop working under this situation. Please check the cause of it, then replace an proper fuse as listed below. Be sure to use the correct fuse before changing the applying voltage.

90V ~ 132V : T 0.8A/250V 198V ~ 250V : T 0.5A/250V F101-102 : T1A/250V F103-104 : T2A/250V

Check the line voltage setting on the rear panel. If the line voltage setting does not match the one of your area, change the line voltage setting according to the following steps:

1. Open the cover of AC socket with flat-blade screwdriver.

2. Remove cam drum, rotate to correct selection and reinsert.

(7) Cleaning the Cabinet

Disconnect the AC power cord before cleaning the instrument. Use a soft cloth dampened in a solution of mild detergent and water. Do not spray

cleaner directly onto the instrument, since it may leak into the cabinet and cause damage.

Do not use chemicals containing benzing, benzne, toluene, xylene, acetone, or similar solvents.

(8) Operation environment

Indoor use Altitude up to 2000m Temperature to satisfy the specification : 18oC ~ 28oC (+64.4oF ~ +82.4oF) Operating temperature : 0oC ~ 40oC (+32oF ~ +104oF) Storage temperature : -10oC ~ 70oC (+14oF ~ 158oF) Relative humidity : up to 90% when 0oC~35oC;

up to 70% when 35

C~40oC

Installation category： II Pollution degree： 2

(9) Place SFG-830 in a location of satisfied environment as stated above free from

dust, direct exposition of sunlight, and strong effect of magnetic fields.

p. 2 SFG-830

(10) For United Kingdom

NOTE

This lead/appliance must only be wired by competent persons.

WARNING

THIS APPLIANCE MUST BE

EARTHED

IMPORTANT

The wires in this lead are coloured in accordance with the following codes:

Green/Yellow Blue Brown

:Earth :Neutral :Live

(Phase)

As the colours of the wires in mains leads may not correspond with the coloured markings identified in your plug/appliance, proceed as follows:

The wire which is coloured Green and Yellow must be connected to the Earth terminal marked with the letter E or by the earth symbol

coloured Green or Green and Yellow. The wire which is coloured Blue must be connected to the terminal which

is marked with the letter N or coloured Blue or Black. The wire which is coloured Brown must be connected to the terminal

marked with the letter L or P or coloured Brown or Red. If in doubt, consult the instructions provided with the equipment or contact the supplier. This cable/appliance should be protected by a suitably rated and approved HBC mains fuse; refer to the rating information on the equipment and/or user instructions for details. As a guide, cable of

0.75mm would normally require 13A types, depending o n the connection method used. Any moulded mains connector that requires removal/replacement must be destroyed by removal of any fuse and fuse carrier and disposed of immediately, as a plug with bared wires is hazardous if engaged in a liv e socket. Any re-wiring must be carried out in accordance with the information detailed in this section.

should be protected by a 3A or 5A fuse. Larger conductors

SFG-830 p.3

2. Product Outline

The frequency synthesis method applied by SFG-830 is Direct Digital Synthesis (DDS), a new technique that generates stable output frequency with extraordinary resolution.

Unlike SFG-830, traditional frequency synthesized function generators typically use Phase Locked Loop (PLL) techniques. In order to synthesize frequencies, PLL should be high-resolution (up to 1:106 in general) and needs a stable frequency to be reference. Due to the utilization of dynamic loop filter, problems such as poor phase jitter and frequency switching response may occur when running the PLL system.

As in generating waveforms, PLL needs a wave-shaping circuit with an address counter that controlled by a variable frequency clock. The counter addresses memory locations in a waveform RAM, and the RAM output is converted by a high speed digital-to-analog converter (DAC) to produce an analog output signal. Problems like poor phase jitter and transient response may arise here as well.

Although DDS also generates analogue waveforms by way of the waveform RAM and high speed DAC, it does not have the problems as PLL does due to the use of fixed frequency clock (fs). Besides, the resolution of DDS is higher than that of PLL’s. DDS’s resolution is fs/2k where the digit of the control frequency word (K), which is more than 32bits in general, decides the quality of it.

Graph1 indicates the fundamental construction of a DDS frequency synthesizer.

(Frequency Control Word)

Accumulator

System

Clock

Digital / Analog

32 24

ROM or RAM

Converter

Lowpass Filter

p. 4 SFG-830

A DDS frequency synthesizer consists of a phase accumulator, a lookout table (ROM or RAM), a Digital-to-Analog Converter (DAC), and a Lowpass Filter (LPF). The amount in a phase accumulator is controlled by the frequency control word (K), which will be added by 1 after each system clock cycle(=1/fs). The output of the accumulator is used to position the data in the Table ROM (or RAM). The digital data will then be converted into a smooth analog waveform after passing through the DAC and LPF.

3. Features

SFG-830 is a functional signal generator that applies DDS (Direct Digital Synthesis) technique and can generate frequencies at a resolution of 20mHz, with a high frequency accuracy of 10ppm. Its main signal source can generate waveforms of sine wave, square wave, triangle wave, ramp wave, and arbitrary wave.

 The output frequency range and resolution of each waveform are:

Waveforms Frequency Range Resolution

Sine wave, square wave 20mHz ~ 30MHz 20mHz Triangle wave, ramp wave 100mHz ~ 100kHz 10mHz Arbitrary wave 42.949600MHz/N, where N=8,10,12,…,2

 The depth of AM modulation : 0% ~ 100%  Sweep range : 10mHz ~ 1kHz  With FM and PSK modulation functions, and the users can choose the modulation

signal source among sine wave, square wave, triangle wave, ramp wave, and arbitrary wave with modulation frequency up to 10kHz.

 The digital modulation and sweep functions provide you a stable and high-

resolution (10mHz) modulation environment.

 SFG-830 has complete environment of computer interface, including standard

RS232 and optional GPIB, to fulfill your requirement of automatic test and control.

 The arbitrary waveform function offers 12000×12bits data length for free compiling.

The user can compile not only with keys on the front panel, but also through a compiling software “Arbitrary Waveform Composer Software for Windows” (optional).

SFG-830 p.5

4. Specifications

Output Function

Frequency Range

Frequency

Resolution

Frequency

Accuracy

Frequency Aging

Output Impedance

Amplitude

Sine, Triangle, Ramp, Square, Sync Output, Arbitrary

Sine 20mHz ~ 30MHz

Square 20mHz ~ 30MHz

Triangle 100mHz ~ 100kHz

Ramp 10mHz ~ 100kHz

Sine / Square 20mHz

Triangle / Ramp 10mHz

± 10 ppm

± 5 ppm / year

Source Impedance

Range

Resolution 3 digits

Accuracy

10mV~10Vp-p (into 50Ω) 8 amplitude

ranges | Vac peak | + | Vdc | < 5V

50Ω ± 10%

± 0.5dB +5mV (Sine out) ± 12% +5mV (Square out) ± 5% +5mV (Triangle out)

DC Offset

Sync Output

Sine Output

Square Output

Triangle and Ramp

± 5% +5mV (Arbitrary out)

Range

Resolution 3 digits

Accuracy

Sync Output TTL levels

Sync Fan-out > 10 TTL load

0.1MHz

Harmonics

1MHz

10MHz

Rise / Fall Time

Overshoot

Asymmetry

Linearity

± 5V (into 50Ω)

| Vac peak | + | Vdc | < 5V

± 1.5% of setting + 1mV

100kHz

1MHz

10MHz

30MHz

≤ 15ns

≤ 5% (at full scale output)

± 1% of period + 4ns

± 0.1% of full scale output

-50dBc

-40dBc

-30dBc

-25dBc

p. 6 SFG-830

Arbitrary

Waveforms

Sample Rate 42.949600MHz/N, N=8, 10, 12,…2

Waveform Length 12,000 points max.

Vertical Resolution 12 bits

Sweep Function Line or Log

Sweep

Modulation

Interface

Sweep Range 20mHz ~ 30MHz

Sweep Time 0.01S ~ 1000S

AM Modulation

Function

Modulation Rate

(sine, triangle, ramp, square)

External, Internal

10mHz ~ 10kHz (Internal)

50kHz (max. external)

Modulation Span 0 ~ 100%

Ext. Input

Ext. Input Impedance

±5V for 100% modulation

100 kΩ

FM Function Sine, Triangle, Ramp, Square

Modulation Rate 10mHz ~ 10kHz

Modulation Span 30mHz (100kHz for triangle, ramp)

PSK Span 360 degrees

Modulation Rate 20Hz ~ 10kHz

RS232 GPIB interface (optional) Arbitrary waveform composer software for Windows(optional)

Accessories

Power Source

Dimensions

Weight

GTL-101 × 1, Instruction Manual × 1

100/120/220/ 240V AC ±10%, 50/60Hz

214 (W) × 89 (H) × 370 (D) mm

Approx. 5kg

SFG-830 p.7

5. Front and Rear Panels

Front Panel

p. 8 SFG-830

POWER button

Push in the button, then the power will be supplied and the display will light up. The power is off when push the button again to the flat position.

UNIT keys

SHIFT key

ENTRY keys

SWEEP/ MODULATE keys

In ‘Normal’ mode, these keys are used to assign the unit and to set the entered value. For example, you can use dBm, Vrms, and Vpp to set the output amplitude. They can be used to set frequency (MHz, kHz, Hz), OFFSET, PHASE, etc. In STOR or RECL modes, they are used as ‘Enter’.

Press this key to set the shift mode, and the SHIFT LED will light up. For example, press [SHIFT] + [DEFAU] can recall the default value of this instrument.

[ 0 ] ~ [ 9 ], [ . ], and [ ± ] keys are used to input value. A unit key should be pressed to set the entered value. [ CLR ] key is used to delete the entered value entirely and bring back the previous value. [ STOR ] key stores the settings into memory. [ RECL ] key recalls the system settings from memory.

These keys control the functions of sweep and modulation. [

] and [ ] keys select the carrier waveform. [AM], [FM], and [PM] keys set the mode of modulation. [ LIN ] and [ LOG ] keys set the sweep method. [ MOD ON/OFF ] initiates sweep or modulation function. As to the functions of [STAR], [STOP], [SPAN], and [RATE] keys, please refer to the instruction in Chapter 6.

MODIFY keys

FUNCTION keys

MAIN OUTPUT BNC

SYNC OUTPUT BNC

Interface LEDs

Parameter display

Unit/Function LEDs

These keys set the size and the increasing or decreasing mode of steps.

These keys controls the output functions. [

] and [ ] keys select the output signal from arbitrary wave (ARB), sine wave, triangle wave, etc. [ FREQ ] key sets the frequency of output. [ AMPL ] key sets the amplitude of output. [ OFFSET ] key sets the DC level of output. [ PHASE ] key sets the phase in PSK modulation mode.

This is the BNC connector that outputs all main signals. Output resistance is 50Ω.

This is the synchronous output BNC connector that outputs a TTL-level signal.

These LEDs indicate the current status when operating with the GPIB interface bus.

This 11-digit display presents the parameter values and information about the current status.

These LEDs indicate the unit of the figures on display and the functions that are currently being used.

SFG-830 p.9

Rear Panel

p. 10 SFG-830

Power Entry model

This is the AC power input terminal. AC input should be within the range of line voltage±10%, 50/60Hz.

Sweep/Modulation output

EXT AM Input

GPIB connector

RS232 connector

This terminal outputs the modulated waveform that is synchronous with the Sweep / Modulation function of this instrument (±5Vpp Max.)

This is the BNC connector for amplitude modulation input. The modulation index is 100% when ±5 is input. The input resistance is 100kΩ.

The optional GPIB (IEEE488.2 and SCPI) communication interface should be plugged here.

This is the port of serial RS232 interface. The DCE and Baud rate is among 300 ~ 19.2k.

6. Operation

6.1 The Setup of Output Function

Use the two buttons [ ] or [ ] in the FUNCTION column on front panel to select

an output waveform. Available waveforms are arranged in sequence SINE, SQU, TRIG, RAMP, and ARB (from left to right).

6.2 The Setup of Frequency

n Press [ FREQ ] button. o Key in the desired value of frequency. p Select a proper unit-button to specify the value.

Example: To set frequency at 250Hz, press [ FREQ ] first; then key in [ 2 ], [ 5 ], [ 0 ], and press

[ Hz ].

The frequency range of waves:

Sine 0.02Hz Square 0.02Hz Triangle 0.1Hz RAMP 0.1Hz ARB 42.949600MHz/N, N=8, 10,12,…2

∼ ∼ ∼ ∼

30MHz 30MHz 100kHz 100kHz

6.3 The Setup of Amplitude

n Press [ AMPL ] button. o Key in the desired value of amplitude. p Select a proper unit-button to specify the value.

Example: To set amplitude at 5Vpp, press [ AMPL ] first, then key in [ 5 ] and press [ Vpp ].

SFG-830 p.11

6.4 The Setup of Offset

n Press [ OFFSET ] button. o Key in the desired value of offset. p Select a proper unit-button to specify the value.

Example: To set offset at 1.2Vpp, press [ OFFSET ] first, then key in [ 1 ], [ . ], [ 2 ], and press

[ Vpp ].

The limitations of input : (1) Amplitude should be among 0.01 ~ 10Vpp.

(2) Offset should be among ±5Vpp. (3) AMPL + 2 × OFFSET ≤ 10Vpp.

6.5 The Setup of Arbitrary-Wave Compiler

This section explains the compiling procedure of arbitrary waveform by using buttons on the front panel. The detailed example of delivering data through optional GPIB will be stated in the chapter of communication interface.

n Set the output function to be “ARB” as stated in section 6.1. o Press [ FREQ ] and the display will show the reading frequency of ARB

function (range 42.9496MHz/N, where N=8, 10, 12,…215).

p Press [ SHIFT ] [ ARB ] to start arbitrary-wave compilation. There will be two

set of figures on the display, the left one indicates the number of a certain point, and the right one represents the value of that point.

q Use [ ] or [ ] buttons in the MODIFY column to check out the value of the

previous or the next point.

r To edit value of a point, press [ SHIFT ] + [

]; key in numbers, and select a

proper unit-button to specify new value of the point.

Note: [ SHIFT ] and [ ] buttons are used together for switching the blinking state between the

number and the value of a point. Following the order of arranged points to compile arbitrary-wave is necessary.

Example of Compiling Arbitrary-Wave

The following example will guide you to proceed the compilation of arbitrary-wave. Here, 8 points (values are identified as 0, 400, 800, 1200, 0, 0, 0, 0 in an order) will be compiled. The changes of waveform will be observed via an oscilloscope.

Procedure : n Use [

] or [ ] buttons in FUNCTION column to select [ ARB ] waveform.

o Press [ SHIFT ] and [ ARB ]. ª The display will show “arb edit” for a while then shows “0001 2047”, which

indicates that you are in the compiling mode and the value of the first point is

2047. The number “0001” will be blinking.

p. 12 SFG-830

+ 33 hidden pages