**LT1761ES5-2#TRPBF: A Comprehensive Guide to the 2V Low-Noise LDO Voltage Regulator**
In the world of precision electronics, maintaining a clean and stable voltage supply is paramount. Noise, ripple, and fluctuations from power sources can severely degrade the performance of sensitive analog circuits, RF systems, and high-resolution data converters. This is where low-dropout (LDO) linear regulators like the **LT1761ES5-2#TRPBF** from Analog Devices become indispensable components. This article provides a deep dive into this specific fixed-voltage regulator, exploring its key features, applications, and design advantages.
The LT1761ES5-2#TRPBF is a member of the LT1761 series of micropower LDO regulators. The "-2" suffix denotes its fixed output voltage of **2.0V**, a common requirement for powering low-voltage microprocessors, memory, and other modern ICs. Housed in a tiny 5-lead SOT-23 package (ES5), it is designed for space-constrained applications. The "TRPBF" indicates it is supplied on tape and reel for high-volume assembly and is lead-free (Pb-free).
**Key Features and Technical Superiority**
What sets the LT1761 apart from standard regulators is its exceptional blend of performance characteristics tailored for noise-sensitive environments.
* **Ultra-Low Noise Output:** The LT1761 is specifically designed to minimize output voltage noise. It achieves an impressively low noise level of **20μVRMS (10Hz to 100kHz)**. This is crucial for powering phase-locked loops (PLLs), voltage-controlled oscillators (VCOs), and precision audio equipment without introducing unwanted interference.
* **Low Dropout Voltage:** With a typical dropout voltage of **300mV** at 100mA load, it can continue to regulate its 2V output even when the input supply drops as low as 2.3V. This maximizes efficiency and extends battery life in portable devices.
* **Micropower Quiescent Current:** The device features a very low quiescent current of **30μA** in operation, which drops to a mere **1μA** in shutdown mode. This makes it ideal for **battery-powered applications** where extending run-time is critical.
* **High Power Supply Rejection Ratio (PSRR):** The regulator excels at rejecting ripple and noise from the input supply, boasting a high PSRR of **76dB at 1kHz** and still over 50dB at 10kHz. This ensures that disturbances on the input line do not propagate to the sensitive load.
* **Wide Input Voltage Range:** It can accept input voltages from **2.3V to 20V**, providing significant design flexibility for systems powered from various sources, including 3.3V, 5V, or unregulated wall adapters.
* **Full Protection Suite:** The IC includes built-in protection against **overcurrent** (short-circuit) conditions and **overtemperature**, enhancing the reliability and robustness of the end product.
**Typical Applications**
The combination of low noise, low dropout, and low quiescent current makes the LT1761ES5-2#TRPBF suitable for a wide array of applications:
* **Portable and Battery-Powered Equipment:** Medical instruments, handheld meters, and IoT sensors.
* **Noise-Sensitive Analog and RF Circuits:** Powering ADCs, DACs, VCOs, PLLs, and precision sensors.
* **Post-Regulation for Switching Supplies:** Used after a noisy switching regulator to provide a clean, quiet output for analog sections of a mixed-signal PCB.
* **2V Microprocessor and Memory Power Supplies.**
**Design Considerations**
While simple to use, a few design practices ensure optimal performance:
1. **Input and Output Capacitors:** Unlike many LDOs that require specific ESR values, the LT1761 is stable with low-ESR ceramic capacitors. A **1–10μF input capacitor** and a **2.2–10μF output capacitor** are typically sufficient for stability and transient response.
2. **Thermal Management:** Although in a small package, the power dissipation (P_DISS = (V_IN - V_OUT) * I_LOAD) must be calculated. For high current and high input voltage differentials, ensure the junction temperature does not exceed the maximum rating of 125°C.
ICGOODFIND: The **LT1761ES5-2#TRPBF** stands out as a premier solution for designers seeking a **high-performance, low-noise 2V power rail**. Its exceptional blend of ultra-low noise, high PSRR, and low power consumption makes it an ideal choice for powering the most sensitive circuits in portable, industrial, and communications equipment, ensuring signal integrity and system reliability.
**Keywords:**
1. **Low-Noise LDO Regulator**
2. **Fixed 2V Output**
3. **High PSRR**
4. **Battery-Powered Applications**
5. **SOT-23 Package**
