## ADM7170ACPZ-R7: Ultra-Low Noise, High PSRR LDO Regulator The **ADM7170ACPZ-R7** is a high-performance CMOS Low Dropout (LDO) linear regulator manufactured by Analog Devices. It is designed specifically for high-performance analog and mixed-signal circuits that require extremely clean power. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Input Voltage Range** | 2.3 V to 6.5 V | | **Maximum Output Current** | 500 mA | | **Output Type** | Adjustable (available in fixed options) | | **Dropout Voltage** | 42 mV (typical at 500 mA) | | **Noise** | 5 μV rms (independent of output voltage) | | **PSRR** | 60 dB at 100 kHz; 40 dB at 1 MHz | | **Operating Temperature** | -40°C to +125°C | | **Package** | 8-lead LFCSP (3 mm × 3 mm) | --- ### 2. Significant Electronic Features * **Ultra-Low Noise:** At 5 μV rms, it is ideal for powering sensitive components like ADCs, DACs, and precision amplifiers without introducing switching noise. * **High Power Supply Rejection Ratio (PSRR):** It effectively filters out ripples from upstream switching power supplies, ensuring a stable DC output even in noisy environments. * **Fast Transient Response:** The device recovers quickly from sudden changes in load current or input voltage, maintaining regulation integrity. * **Precision Enable (EN) Pin:** Includes a precision enable input that allows the device to be turned on or off via external logic, facilitating power sequencing. * **Adjustable Soft Start:** Allows the user to control the ramp-up time of the output voltage to limit inrush current. --- ### 3. Pin Configuration & Application The ADM7170ACPZ-R7 typically utilizes the following pinout in its 8-lead LFCSP package: 1. **VOUT:** Regulated output voltage. 2. **SENSE / ADJ:** Connects to the output or a resistor divider to set the voltage. 3. **GND:** Ground reference. 4. **EN:** Enable input (High = On, Low = Off). 5. **SS:** Soft-start capacitor connection. 6. **VIN:** Input supply voltage. 7. **NC:** No internal connection. 8. **EP:** Exposed Pad (must be soldered to GND for thermal dissipation). --- ### 4. Common Applications * Regulation for high-speed ADCs and DACs. * RF and PLL power supplies. * Medical imaging and precision instrumentation. * Post-regulation for switching power supplies to remove high-frequency ripple. --- ### 5. Order Code Breakdown * **ADM7170:** Base model number. * **ACPZ:** Indicates the package (LFCSP) and RoHS compliance (Lead-free). * **R7:** Indicates the tape and reel packaging size (7-inch reel).