Saleae produces four logic analyzers with a range of capabilities. If you are unsure of which one you will need based on the technical specifications alone, you can find common applications and recommendations here.
Please also keep in mind that Saleae offers a 180-day return policy, which includes return shipping. If you decide that you need to upgrade your device or you don't need all the capabilities of the unit you purchased, you have 180 days to change your mind.
All products support directly recording large swing signals such as RS-232 and RS-485 and have protection from signals up to +/-25 volts. They have a 3-year warranty.
The Saleae Logic 4 logic analyzer was designed with students, hobbyists, and beginners in mind. There are many applications where it is all you need.
Recording common low-speed protocols such as 9600 baud serial, I2C, and SPI (up to 3 MHz). The software includes all of the Saleae protocol analyzers, so Logic 4 is perfect for any protocol where 4 or fewer channels are required and where protocol bit rates don't exceed 3 mbps.
Recording low-speed analog signals such as audio, current sense resistors, batter voltages over long periods of time, and so on. The analog input can record signals between 0 and 5 volts with 8 bits of precision.
Recording servo signals, taking duty cycle measurements, recording robotic sensors, and actuator outputs and control signals.
The Saleae Logic 8 is a considerable jump in technical capabilities over the Logic 4. Not only does the channel count double, but the number of analog inputs goes from 1 to 8, and the digital and analog sample rates dramatically increase. Logic 8 is a good bet if you're not sure what requirements you will have in the future.
Typical applications where you would need a Logic 8 instead of a Logic 4:
Recording more than 4 signals at once. Examples:
A mix of debug IO pins and protocols
SPI bus with multiple slave select lines
Up to 8 channels of serial
Recording higher-speed protocols such as USB full speed or JTAG. Logic 8 can sample at up to 100 MHz on 3 channels.
Taking higher precision-duty cycle and frequency measurements. When taking precise frequency or duty cycle measurements, significant oversampling is required, preferably 100x or higher.
Recording multiple channels of analog such as stereo sound or audio at multiple points of a filter chain.
Logic Pro 8
The Saleae Logic Pro 8 is one of the two USB 3.0 logic analyzers made by Saleae. It has a significant number of features designed with professional engineers in mind. For high-speed or low-voltage applications, the Logic Pro devices are the best-suited choice.
Special features of the Logic Pro devices:
USB 3.0 allows digital sample rates up to 500 MSPS on up to 4 channels at once. This is ideal for any signals running up to 100 MHz in bandwidth or for maximally precise frequency or duty cycle measurements.
Support for sampling digital at 100 MSPS on all channels at once (25 MHz bandwidth)
Analog sample rates up to 50 MSPS (5 MHz bandwidth)
Selectable threshold support for logic IO levels down to 1.2 volts
Bipolar analog inputs supporting a wide range from -10 to +10 volts
12-bit analog resolution (~5mV/div)
Perfect for medium-speed FPGA applications, low-voltage designs, high-speed protocol decoding, accurate duty cycle and frequency measurements, data-intensive applications such as 8-channel I2S audio, and high-speed SPI.
Logic Pro 16
The Saleae Logic Pro 16 is the flagship logic analyzer from Saleae. It has similar technical specifications to the Logic Pro 8, but with 16 channels, all of which support operating as digital inputs, analog inputs, or both.
In addition to being able to record up to 4 digital channels at 500 MSPS, it's also able to record all 16 inputs at 100 MSPS at one time.
The additional channels mean it's unlikely that you will run out of available inputs, which can save time and frustration when recording only small sets of signals one at a time would be required. It also allows you to record up to 15-bit parallel clocked protocols, which is especially useful for recording 8-bit parallel interfaces where other products would only be able to support up to 7 data bits and one clock bit.
Still not sure? Just ask us!
If you're still not sure which unit will meet your needs, just write in with a description of your application. Please include any technical information that you already have about your design, and we can provide feedback.