Low power Standalone Arbitrary Waveform Generator

This is our effort to create an affordable arbitrary waveform generator to provide engineering students and hobbyists access to top-quality portable waveform generators. The initial version was a technical exploration of major test and measurement equipment. During this exploration, we attempted to replicate a waveform generator to grasp the theory and challenges involved. Subsequently, we realized the demand for such instruments among individuals unable to afford industry-grade, expensive waveform generators. As a result, we streamlined and retained numerous features in Wavengine Simplistic.

Our journey began with the Texas Instruments India Innovation Challenge 2016. During this competition, we triumphantly crafted and assembled our inaugural prototype. It featured top-tier components typically found in standard laboratories, including the FPGA, THS3062 (high-speed op-amps), DAC904 (14-bit digital-to-analog converter), 64K x 16 SRAM, TPS65131 split rail power supply and more. To facilitate testing, we fabricated single-layered PCBs for these ICs.

In 2017, we aimed to develop a commercially viable product with respectable specifications within a semester. To achieve this, we boldly replaced expensive, easy-to-use components with general-purpose ICs to reduce costs, power consumption, and space requirements.

We actively welcome and encourage improvements. In any test and measurement application, having a reliable signal source is crucial for comprehending circuit behavior within a network. This design empowers any electronics engineer or student to easily obtain an arbitrary waveform generator and deploy it whenever needed.

Second prototype after assembly

Output waveform using Keysight DSO1052B

Utilizing the ARM Cortex M3/M4 core, this implementation consolidates both the user application program and waveform generation program onto a single chip, resulting in significant cost reduction. Leveraging 32-bit general-purpose registers as phase accumulators, frequency, and phase registers ensures high sampling rates and consistent frequency resolution. Internal SRAM serves to store sampling data efficiently.

The algorithm is realized in assembly using the THUMB instruction set, optimizing for performance. The final product is manufactured using a low-cost MCU based on this design. It provides 8-bits of resolution. Emphasizing the ARM architecture, this design ensures independence from specific silicon manufacturers regarding algorithm implementation.

SFDR @ 100KHz = -50dBc

The waveform generation utilizes DDS, a widely used method for creating digitally controlled, agile, and temperature-insensitive waveforms. All necessary components and modules are seamlessly integrated into a single PCB. An on-board Rail-to-Rail power supply circuit is incorporated to power the operational amplifiers efficiently. The output is equipped with the capability to drive a 50-ohm load impedance for transmission line impedance matching. The USB 2.0 peripheral of the same MCU is also utilized for firmware updates, downloading arbitrary waveforms, and USB control from other USB-compliant host devices.

Video Demonstration of First Prototype

Bill of Materials

Sr. No Description Manufacturer Manufacturer Part Number
1. No. of Amplifiers:2; Bandwidth:100MHz; Slew Rate:3000V/µs; Supply Voltage Range:5.5V to 36V; TEXAS INSTRUMENTS LM6172IM/NOPB
2. BJT NPN, 40V, ft:300MHz; Power Dissipation Pd:350mW; DC Collector Current:200mA ON SEMICONDUCTOR MMBT3904
3. OP AMP 1.1MHZ, 0.6V/µS, SOIC-8; No. of Amplifiers:2; Bandwidth:1.1MHz; Slew:0.6V/µs; 3V to 30V STMICROELECTRONICS LM358DT
4. DC/DC CONTROLLER, SOIC-8; Topology:Buck, Boost, Inverting; Output Current:1.5A; TEXAS INSTRUMENTS MC34063ADE4
5. MICRO USB, 2.0 MOLEX 105017-0001
6. THICK FILM, 220R, 1%, 0.125W, 0805; Resistance:220ohm; YAGEO (PHYCOMP) RC0805FR-07220RL
7. Ceramic Capacitor Case:0805 [2012 Metric]; Capacitance:270pF; Voltage Rating:50V; Capacitance Tolerance:± 5% MULTICOMP MC0805N271J500CT
8. Ceramic Capacitor Case:0805 [2012 Metric]; Capacitance:22pF; Voltage Rating:50V; Capacitance Tolerance:± 5% KEMET C0805C220J5GACTU
9. Ceramic Capacitor Case:0805 [2012 Metric]; Capacitance:0.1µF; Voltage Rating:50V; Capacitance Tolerance:± 10% KEMET C0805C104K5RACTU
10. Ceramic Capacitor Case:0805 [2012 Metric]; Capacitance:180pF; Voltage Rating:50V; Capacitance Tolerance:± 5% MULTICOMP MC0805N181J500CT
11. Power Inductor semi-shielded, Inductance:10µH; RMS Current (Irms):2.1A; Saturation Current (Isat):2.3A BOURNS SRN5040-100M
12. Rotary Potentiometer ; Track Resistance: 100 kohm ± 20%; 50mW BOURNS PTV09A-4020U-B104.
13. Resistance Thick Film, 1K, 1%, 0.125W, 0805 MULTICOMP MCWR08X1001FTL
14. Resistance Thick Film, 2K, 1%, 0.125W, 0805 MULTICOMP MCWR08X2001FTL
15. Resistance Thick Film, 2.7K, 1%, 0.125W, 0805 MULTICOMP MCWR08X2701FTL
16. Resistance Thick Film, 1.5K, 1%, 0.125W, 0805 MULTICOMP MCWR08X1501FTL
17. Resistance Thick Film, 120R, 1%, 0.125W, 0805 MULTICOMP MCWR08X1200FTL
18. Resistance Thick Film, 604R, 1%, 0.125W, 0805 PANASONIC ELECTRONIC COMPONENTS ERJ-6ENF6040V
19. SMD Electrolytic Aluminium capacitor, Capacitance:100µF 20%; Voltage Rating:16V NICHICON UWX1C101MCL1GB
20. SMD Electrolytic Aluminium capacitor, Capacitance:10µF 20%; Voltage Rating:16V NICHICON UWX1C100MCL2GB
21. SMD Electrolytic Aluminium capacitor, Capacitance:330µF 20%; Voltage Rating:16V NICHICON UWT1C331MNL1GS
22. Wirewound Inductor, Inductance:10 H; DC Current Rating:155mA TAIYO YUDEN LB2016T100M
23. Ceramic Capacitor Case:0805 [2012 Metric]; Capacitance:100nF; Voltage Rating:50V; Capacitance Tolerance:± 5% YAGEO (PHYCOMP) CC0805ZRY5V9BB104
24. Ceramic Capacitor Case:0805 [2012 Metric]; Capacitance:1nF; Voltage Rating:50V; Capacitance Tolerance:± 5% YAGEO (PHYCOMP) CC0805KRX7R9BB102
25. Power Inductor semi-shielded, Inductance:47µH; RMS Current (Irms):1.4A; Saturation Current (Isat):1.5A BOURNS SRN8040-470M
26. Schottky Diode, Vrrm Max:40V; Forward Current If(AV): 3A; DIODES INC. B340A-13-F
27. Tantalum Capacitor Capacitance:10µF; Voltage Rating:25V; Capacitance Tolerance:± 10% KEMET T491A106M016AT
28. Tantalum Capacitor Capacitance:4.7µF; Voltage Rating:25V; Capacitance Tolerance:± 10% KEMET T491A475K025AT
29. Signal Relay DPDT 5V. TE CONNECTIVITY / AXICOM V23105A5001A201
30. Resistance Thick Film, 49R9, 1%, 0.66W, 1206 PANASONIC ELECTRONIC COMPONENTS ERJP08F49R9V
31. Resistance Thick Film, 180R, 1%, 0.125W, 0805 MULTICOMP MC0805S8F1800T5E
32. Resistance Thick Film, 1R, 1%, 0.125W, 0805 MULTICOMP MCWR08W1R00FTL
33. Resistance Thick Film, 4K7, 1%, 0.125W, 0805 MULTICOMP MCWR08X4701FTL
34. XTAL, 8.000MHZ, 18PF, SMD, HC-49S; Frequency Stability + / -:10ppm; Load Capacitance:18pF; TXC 9C-8.000MEEJ-T
35. Resistance Thick Film, 12K, 1%, 0.66W, 1206 MULTICOMP MCWR08X1202FTL
36. Linear Regulator SOT 223-3 Fixed Output Voltage : 3.3V; Output Current : 800mA TAIWAN SEMICONDUCTOR TS1117BCW-3.3
37. STM32 ARM Cortex M3 , 72MHz, Flash - 64KB , RAM - 20KB STMICROELECTRONICS STM32F103C8T6