The SN6505x-Q1 is a low-noise, low-EMI push-pull transformer driver, specifically designed for small form factor, isolated power supplies. It drives low-profile, center-tapped transformers from a 2.25 V to 5 V DC power supply. Very low noise and EMI are achieved by slew rate control of the output switch voltage and through Spread Spectrum Clocking (SSC). The SN6505x-Q1 consists of an oscillator followed by a gate drive circuit that provides the complementary output signals to drive ground-referenced N-channel power switches. The device includes two 1-A Power-MOSFET switches to ensure start-up under heavy loads. The switching clock can also be provided externally for accurate placement of switcher harmonics, or when operating with multiple transformer drivers. The internal protection features include a 1.7 A current limiting, under-voltage lockout, thermal shutdown, and break-before-make circuitry. SN6505A-Q1 and SN6505B-Q1 include a soft-start feature that prevents high inrush current during power up with large load capacitors. Soft-start feature has been disabled in SN6505D-Q1 for applications that require fast output start-up.SN6505A-Q1 has a 160 kHz internal oscillator for applications that need to minimize emissions whereas SN6505B-Q1 and SN6505D-Q1havea 420 kHz internal oscillators for applications that require higher efficiency and smaller transformer size. The SN6505x-Q1 is available in a small 6-pin SOT23/DBV package. The device operation is characterized for a temperature range from -40°C to 125°C.
| Top documentation | Type | Title | Format options | Date |
|---|---|---|---|---|
| * | Data sheet | SN6505x-Q1 Low-Noise 1-A Transformer Drivers for Isolated Power Supplies datasheet (Rev. D) | PDF | HTML | Oct 26, 2020 |
| Product overview | Isolated Power Topologies for PLC I/O Modules and Other Low-Power Applications (Rev. A) | PDF | HTML | Aug 20, 2024 | |
| Application note | How to Reduce Emissions in Push-Pull Isolated Power Supplies (Rev. A) | PDF | HTML | Oct 5, 2021 | |
| Functional safety information | SN6505x-Q1 Functional Safety, FIT Rate, Failure Mode Distribution and Pin FMA | PDF | HTML | Jun 18, 2020 | |
| Application brief | How to Use Push-Pull Transformer Drivers to Replace Solid-State and Mechanical R | PDF | HTML | Feb 23, 2020 |
For additional terms or required resources, click any title below to view the detail page where available.
The evaluation module (EVM), featuring a SN6505B transformer driver, also contains a small form-factor transformer, simple rectifier circuit, and voltage regulator that can be used to simulate a complete isolated power-supply system suitable for many applications.
| Package | Pins | CAD symbols, footprints & 3D models |
|---|---|---|
| SOT-23 (DBV) | 6 | Ultra Librarian |
Recommended products may have parameters, evaluation modules or reference designs related to this TI product.
Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.
If you have questions about quality, packaging or ordering TI products, see TI support.