Overview
The TPS78618DCQ, produced by Texas Instruments, is a member of the TPS786 family of low-dropout (LDO) linear voltage regulators. This device is designed to provide high performance in noise-sensitive applications, such as RF, audio, and Bluetooth systems. It features ultralow noise, high power-supply rejection ratio (PSRR), and fast start-up times, making it ideal for use in portable RF electronics and other sensitive analog circuits.
Key Specifications
| Parameter | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|
| Input Voltage (VIN) | 2.7 | 5.5 | V | |
| Output Current (IOUT) | 0 | 1.5 | A | |
| Operating Junction Temperature (TJ) | -40 | 125 | °C | |
| Output Voltage Accuracy | -2% | 2% | ||
| Dropout Voltage (at 1.5 A) | 390 | 550 | mV | |
| PSRR at 10 kHz | 49 | dB | ||
| Output Noise (at 3 V, 0.1 μF bypass capacitor) | 48 μVRMS | |||
| Start-Up Time | 50 μs | |||
| Quiescent Current | 265 μA | |||
| Package Type | DCQ (SOT-223) |
Key Features
- Ultralow noise: 48 μVRMS at 3 V output with a 0.1 μF bypass capacitor.
- High PSRR: 49 dB at 10 kHz.
- Fast start-up time: Approximately 50 μs with a 0.001 μF bypass capacitor.
- Low dropout voltage: 390 mV at 1.5 A.
- Stable with a small 1 μF ceramic output capacitor.
- Excellent line and load transient responses.
- Enable input to reduce supply current to less than 1 μA in shutdown mode.
- Internal current limiting and thermal protection.
Applications
- RF applications: VCOs, receivers, ADCs.
- Audio systems.
- Bluetooth and Wireless LAN devices.
- Cellular and cordless telephones.
- Handheld organizers and PDAs.
Q & A
- What is the maximum output current of the TPS78618DCQ? The maximum output current is 1.5 A.
- What is the typical quiescent current of the TPS78618DCQ? The typical quiescent current is 265 μA.
- What is the dropout voltage at full load for the TPS78618DCQ? The dropout voltage at 1.5 A is approximately 390 mV.
- How does the enable input function on the TPS78618DCQ? Driving the enable input (EN) above 1.7 V turns on the regulator, while driving it below 0.7 V puts the regulator into shutdown mode, reducing the supply current to less than 1 μA.
- What is the recommended output capacitor for the TPS78618DCQ? The minimum recommended output capacitor is 1 μF, but any 1 μF or larger ceramic capacitor is suitable.
- What is the PSRR of the TPS78618DCQ at 10 kHz? The PSRR at 10 kHz is 49 dB.
- How does the TPS78618DCQ handle thermal protection? The device features thermal protection that shuts it down if the temperature exceeds approximately 165°C and resumes operation once it cools down below approximately 140°C.
- What are the package options for the TPS78618DCQ? The TPS78618DCQ is available in the DCQ (SOT-223) package.
- What is the typical start-up time for the TPS78618DCQ? The typical start-up time is approximately 50 μs with a 0.001 μF bypass capacitor.
- How does the noise reduction work on the TPS78618DCQ? The noise is reduced using a bypass capacitor connected to the NR pin, which creates a low-pass filter to minimize voltage reference noise.
