Overview
The LT1931IS5#TRPBF, produced by Analog Devices Inc., is a high-power inverting DC/DC converter integrated into a compact 5-lead ThinSOT package. This device is part of the LT1931/LT1931A series, which are known for their high current output capabilities and low noise operation. The LT1931 switches at a fixed frequency of 1.2MHz, while the LT1931A switches at 2.2MHz, enabling the use of small, low-cost capacitors and inductors. These converters are ideal for applications requiring a negative voltage supply from a positive input voltage.
Key Specifications
| Parameter | Value |
|---|---|
| Switching Frequency | 1.2MHz (LT1931), 2.2MHz (LT1931A) |
| Input Voltage Range | 2.6V to 16V |
| Output Voltage | –5V at 350mA, –12V at 150mA from 5V input |
| Integrated Switch Current | 1A |
| Output Ripple | 1mVP-P |
| Shutdown Current | <1µA |
| Maximum Operating Temperature | 85°C |
| Minimum Operating Temperature | –40°C |
| Package Type | 5-lead ThinSOT (TSOT-23) |
| VCESAT Switch | 400mV at 1A |
Key Features
- Fixed frequency operation at 1.2MHz or 2.2MHz, reducing low frequency noise.
- Very low output voltage ripple of 1mVP-P using ceramic output capacitors.
- High current output capability with a 1A integrated switch.
- Low shutdown current of less than 1µA.
- Low VCESAT switch of 400mV at 1A.
- Pin-for-pin compatible with the LT1611.
- Compact ThinSOT package with a low profile of 1mm.
- Dual inductor inverting topology for efficient current filtering.
Applications
- Disk Drive MR Head Bias
- Digital Camera CCD Bias
- LCD Bias
- GaAs FET Bias
- Local Low Noise/Low Impedance Negative Supply
Q & A
- What is the switching frequency of the LT1931 and LT1931A? The LT1931 switches at 1.2MHz, while the LT1931A switches at 2.2MHz.
- What is the input voltage range for the LT1931/LT1931A? The input voltage range is from 2.6V to 16V.
- What are the typical output voltages and currents for the LT1931? The LT1931 can generate –5V at 350mA or –12V at 150mA from a 5V supply.
- What is the maximum operating temperature for the LT1931IS5#TRPBF? The maximum operating temperature is 85°C.
- What is the shutdown current of the LT1931/LT1931A? The shutdown current is less than 1µA.
- What package type is used for the LT1931IS5#TRPBF? The device is packaged in a 5-lead ThinSOT (TSOT-23).
- What is the VCESAT of the integrated switch at 1A? The VCESAT is 400mV at 1A.
- Is the LT1931/LT1931A pin-for-pin compatible with other devices? Yes, it is pin-for-pin compatible with the LT1611.
- What is the typical output ripple of the LT1931/LT1931A? The output ripple is very low, approaching 1mVP-P.
- What are some common applications for the LT1931/LT1931A? Common applications include disk drive MR head bias, digital camera CCD bias, LCD bias, GaAs FET bias, and local low noise/low impedance negative supply.
