• The ADP2165 supports a continuous output current of 5 A, while the ADP2166 supports 6 A.
• Integrated MOSFETs with high-side on resistance of 19 mΩ and low-side on resistance of 15 mΩ.
• Reference voltage is 0.6 V ± 1% over the temperature range.
• Input voltage range is from 2.7 V to 5.5 V.
• Current mode architecture with both fixed and adjustable switching frequencies.
• Synchronization to an external clock with selectable phase shift.
• Features external compensation and programmable soft start.
• Protection features include undervoltage lockout, overvoltage protection, overcurrent protection, and thermal shutdown.

• Point of load regulation.
• Communications and networking.
• High-end consumer electronics.
• Industrial, instrumentation, and healthcare sectors.

The ADP2165/ADP2166 are high-efficiency, current mode control, step-down DC-to-DC regulators. They feature an integrated high-side FET and a synchronous rectified FET, offering a compact solution with high power density. The devices support robust sequencing with precision enable, power-good monitor, and output voltage tracking. The switching frequency is programmable or can be synchronized to an external clock to minimize EMI.

• Input voltage range: 2.7 V to 5.5 V.
• Output voltage options: Fixed outputs (3.3 V, 2.5 V, 1.8 V, 1.5 V, 1.2 V, 1.0 V) and adjustable options.
• Operating temperature range: -40°C to +125°C.
• Available in a 24-lead, 4 mm × 4 mm LFCSP_WQ package.

Efficiency graphs demonstrate performance across different output currents and input voltages, highlighting the device's efficiency under various conditions.

• Selection of input and output capacitors is crucial for optimal performance.
• Inductor selection affects efficiency and transient response.
• Compensation design is necessary for stability and performance tuning.

• Undervoltage lockout (UVLO) ensures safe voltage levels.
• Overvoltage protection (OVP) and overcurrent protection (OCP) safeguard against excessive conditions.
• Thermal shutdown (TSD) prevents overheating.

The ADP2165/ADP2166 are step-down, DC-to-DC regulators designed for high-performance applications requiring high efficiency and design simplicity. They operate with an input voltage range of 2.7 V to 5.5 V and can regulate output voltages down to 0.6 V. Key features include programmable switching frequency, soft start, external compensation, and enable and power-good pins. Preset output voltage options are available for 3.3 V, 2.5 V, 1.8 V, 1.5 V, 1.2 V, and 1.0 V.

The regulators use a fixed frequency, current mode PWM control architecture for optimal line and load transient performance. The PWM mode adjusts the duty cycle of the integrated MOSFET to regulate the output voltage with low ripple.

The EN input pin has a precision analog threshold of 1.2 V with 100 mV hysteresis. The regulator turns on when the enable voltage exceeds 1.2 V and turns off when it falls below 1.1 V. An internal pull-down resistor prevents accidental enable if the EN pin is not externally connected.

The internal regulator provides a stable supply for control circuits and includes a current-limit circuit for protection. A 1 µF ceramic capacitor is recommended between the VREG and GND pins.

The integrated boot regulator provides gate drive voltage for the high-side NFET. A 0.1 µF ceramic capacitor between the BST and SW pins is recommended.

The switching frequency is set by a resistor between the RT and GND pins. The frequency can be synchronized with an external clock ranging from 250 kHz to 1.4 MHz.

The soft start time is programmable via a capacitor between the SS and GND pins. The soft start prevents reverse inductor current during startup.

The TRK feature allows the output voltage to track another voltage, useful for core and I/O voltage tracking in FPGAs, DSPs, and ASICs.

The PGOOD pin indicates whether the output voltage is within ±10% of the desired value, with a 16-cycle delay for assertion and deassertion.

The regulators include peak current-limit, short-circuit, overvoltage, undervoltage lockout, and thermal shutdown protections to ensure safe operation under various conditions.

The ADP2165/ADP2166 are supported by the ADIsimPower design tool, which helps generate optimized power designs. Input and output capacitor selection guidelines are provided to minimize voltage ripple and ensure stability.

The inductor value is influenced by operating frequency, input voltage, output voltage, and inductor ripple current. A smaller inductor results in faster transient response but lower efficiency due to higher ripple current, while a larger inductor improves efficiency but slows transient response. The ripple current is typically set to one-third of the maximum load current. The inductor value is calculated using the formula: L = (V_IN - V_OUT) / (f_SW × ΔI_L × D), where D is the duty cycle. For duty cycles over 50%, a minimum inductor value is required to prevent subharmonic oscillations. The peak inductor current should not exceed the inductor's saturation current.

The output capacitor affects ripple voltage, load step transient, and loop stability. It supplies the load during transient events until the control loop adjusts the inductor current. The required capacitance for undershoot and overshoot is calculated using specific formulas. The largest capacitance from these calculations should be selected to meet performance requirements. The capacitor's voltage rating must exceed the output voltage, and its RMS current rating must be sufficient.

Compensation involves selecting components to stabilize the control loop. The power stage is modeled as a voltage-controlled current source. The compensation components (R_C, C_C, and optional C_CP) are selected based on the desired cross frequency and the characteristics of the output capacitor. The design guidelines provide equations for calculating these components.

A design example is provided with specific parameters: input voltage of 5V, output voltage of 1.2V, output current of 6A, and a switching frequency of 1.2 MHz. The example includes calculations for inductor and capacitor selection, compensation components, and soft start time. Recommended components are listed for achieving the desired performance.

Good PCB layout is crucial for optimal performance. Separate analog and power ground planes should be used, with components placed close to the IC and short traces for high current paths. The feedback resistor network should be close to the FB pin to minimize noise pickup. A large copper plane should be used for thermal dissipation.

The document provides detailed reference designs for the ADP2165/ADP2166 step-down regulators. These include configurations for different output voltages and synchronization options, such as 1.2 V, 1.8 V, and 3.3 V outputs with varying synchronization frequencies and tracking modes.

Key components include inductors (L1), input capacitors (CIN), output capacitors (COUT), and various resistors and capacitors for feedback and compensation networks. Specific values are provided for each configuration, such as L1 values ranging from 0.47µH to 0.82µH and COUT values from 100µF to 470µF.

The ADP2165/ADP2166 is housed in a 24-lead Lead Frame Chip Scale Package (LFCSP_WQ) with dimensions of 4 mm x 4 mm. The document includes detailed measurements and compliance with JEDEC standards.

The guide lists various models of the ADP2165 and ADP2166, specifying output currents (5A or 6A), temperature ranges (-40°C to +125°C), and output voltages (ranging from adjustable to fixed values like 1.0V, 1.2V, 1.5V, etc.). Evaluation boards are also available for both models.