Summary of LTC7812 – Low IQ, 38V Synchronous Boost+Buck Controller
The article briefly introduces the FISH 8840, an inexpensive component tester priced around $30. It features a simple interface with a test button, ZIF socket for leaded components, and pads for SMD devices. The device displays recognized components on a screen with schematic diagrams. However, the text contains a discrepancy, linking the tester description to the LTC7812 Boost+Buck Controller datasheet features instead of detailing the tester's internal components or project parts list. Consequently, no specific project parts can be extracted from the provided text as it lacks a buildable project description for the FISH 8840.
Parts used in the Project:
- No specific parts listed; the article describes a commercial product rather than a DIY project.
Features
- Synchronous Boost and Buck Controllers
- When Cascaded, Allows VIN Above, Below, or Equal to Regulated VOUT
- Output Remains in Regulation Through Input Dips (e.g., Cold Crank) Down to 2.5V
- Wide Bias Input Voltage Range: 4.5V to 38V
- Low Input and Output Ripple
- Low EMI
- Fast Output Transient Response
- High Light Load Efficiency
- Low Operating IQ: 33μA (Both Channels On)
- Low Operating IQ: 28μA (Buck Channel On)
- RSENSE or Lossless DCR Current Sensing
- Buck Output Voltage Range: 0.8V ≤ VOUT ≤ 24V
- Boost Output Voltage Up to 60V
- Phase-Lockable Frequency (75kHz to 850kHz)
- Small 32-Pin 5mm × 5mm QFN Package
This is an inexpensive component tester called the FISH 8840 which you can find from many online eBay retailers for around $30. The interface is very simple, attach a device to be tested and press the test button. It turns off after about 20 seconds, pressing the off button puts it into sleep mode immediately. There is a ZIF socket that allows you to insert leaded devices and pads that allow you to press SMD devices directly onto the tester. Their are number 1 through 3 on the tester where you connect the device under test to and then the screen will display the recognized component with the lead numbers on a component schematic picture. There seems to be an issue with the capacitor testing mode with a range of values, I will discuss this with the seller to see what the resolution to this is. I have seen this tester work fine with capacitors so I think it is just something with this one. You can see the features and functions below.
For more detail: LTC7812 – Low IQ, 38V Synchronous Boost+Buck Controller
- How much does the FISH 8840 cost?
The FISH 8840 costs around $30 and can be found from many online eBay retailers. - What is the power-off behavior of the tester?
The device turns off automatically after about 20 seconds of inactivity. - Can I put the tester into sleep mode immediately?
Yes, pressing the off button puts the tester into sleep mode immediately. - How do I connect SMD devices to the tester?
You can press SMD devices directly onto the pads provided on the tester. - Does the tester support testing capacitors?
The tester has a capacitor testing mode, though there may be issues with specific value ranges on individual units. - What information does the screen display?
The screen displays the recognized component along with lead numbers on a component schematic picture.
