The **ADP7185ACPZN3.3-R7** is a high-performance, low-dropout (LDO) linear regulator manufactured by Analog Devices. It is specifically designed for applications requiring high precision, low noise, and high power supply rejection ratio (PSRR). --- ## 1. Technical Specifications The table below outlines the primary electrical characteristics of the ADP7185ACPZN3.3-R7: | Parameter | Specification | | :--- | :--- | | **Output Voltage** | 3.3 V (Fixed) | | **Input Voltage Range** | -2.0 V to -5.5 V | | **Output Current** | 500 mA (Maximum) | | **Dropout Voltage** | 190 mV (Typical at 500 mA) | | **PSRR** | 80 dB (at 1 kHz); 40 dB (at 1 MHz) | | **Output Noise** | 4 μV rms (10 Hz to 100 kHz) | | **Operating Temperature** | -40°C to +125°C | | **Package** | 8-Lead LFCSP (3mm x 3mm) | --- ## 2. Key Features ### Ultralow Noise and High PSRR This regulator is engineered to filter out noise from switching power supplies, making it ideal for sensitive analog circuits. Its low output noise (4 μV rms) ensures minimal interference with downstream components. ### Negative Input/Output Unlike standard positive regulators, the ADP7185 handles **negative voltages**. This is critical for bipolar signal chains where both positive and negative rails are required. ### Protection Mechanisms * **Thermal Overload Protection:** Shuts down the device if the junction temperature exceeds safety limits. * **Current-Limit Protection:** Protects the device and the load from short-circuit conditions. * **Programmable Soft Start:** Allows the user to control the ramp-up speed of the output voltage to reduce inrush current. --- ## 3. Pin Configuration (8-Lead LFCSP) | Pin No. | Name | Description | | :--- | :--- | :--- | | 1 | VOUT | Regulated negative output voltage. | | 2 | SENSE | Feedback input for voltage regulation. | | 3 | ADJ/SS | Adjust pin for variable versions or Soft Start timing for fixed versions. | | 4 | EN | Enable input. Drive high to turn on the device. | | 5 | GND | Ground reference. | | 6 | VIN | Negative supply input voltage. | | 7 | NC | No internal connection. | | 8 | PG | Power Good output (indicates the output is stable). | | EP | Exposed Pad | Must be connected to GND for thermal dissipation. | --- ## 4. Typical Applications * **RF and Microwave:** Powering low-noise amplifiers (LNAs) and VCOs. * **Data Conversion:** Providing clean power to High-Speed ADCs and DACs. * **Medical Imaging:** Used in precision ultrasound or MRI signal processing. * **Communications:** Powering optical modules and base station equipment. ---