The **ADP7185ACPZN2.5-R7** is a high-performance, low dropout (LDO) linear regulator manufactured by Analog Devices. It is specifically designed for high-precision applications requiring low noise and high power supply rejection ratios (PSRR). --- ### ## Technical Specifications | Parameter | Details | | :--- | :--- | | **Manufacturer** | Analog Devices Inc. | | **Input Voltage Range** | -2.0V to -5.5V | | **Fixed Output Voltage** | -2.5V | | **Maximum Output Current** | 500 mA | | **Dropout Voltage** | 190 mV (typical at 500 mA) | | **PSRR** | 80 dB (at 1 kHz); 40 dB (at 1 MHz) | | **Operating Temperature** | -40°C to +125°C | | **Package / Case** | 8-Lead LFCSP (3mm x 3mm) | --- ### ### Key Features 1. **Ultra-Low Noise:** It produces only **4 μV rms** (100 Hz to 100 kHz), making it ideal for powering sensitive analog components like ADCs and DACs. 2. **High PSRR:** Excellent filtering of upstream switching power supply noise. 3. **Negative Voltage Regulation:** Unlike standard regulators, this is a **CMOS negative LDO**, meaning it regulates negative rails (e.g., -2.5V from a -5V source). 4. **Precision Enable:** Includes an enable pin with a precision threshold for easy sequencing. 5. **Protection Features:** Integrated current-limit and thermal shutdown circuitry. --- ### ### Pin Configuration (8-Lead LFCSP) | Pin No. | Name | Function | | :--- | :--- | :--- | | 1 | VOUT | Regulated negative output voltage (-2.5V). | | 2, 3 | VIN | Negative input voltage source. | | 4 | GND | Ground reference. | | 5 | EN | Enable input. Drive high to turn on; low to shut down. | | 6 | NC | No internal connection. | | 7 | SS | Soft start capacitor connection to reduce inrush current. | | 8 | SENSE | Feedback connection to the load for precision regulation. | | EP | Exposed Pad | Must be connected to GND for thermal dissipation. | --- ### ### Application Use Cases * **Precision Instrumentation:** Powering high-resolution data converters. * **RF and Microwave:** Low-noise power for VCOs and mixers. * **Medical Imaging:** Used in ultrasound or MRI signal processing where noise floors must be minimal. * **Optical Networking:** Powering laser drivers and sensitive receivers.