AOZ1282CI — 1.2 A Simple Buck Regulator

{
  "schema_version": 1,
  "type": "component",
  "slug": "aoz1282ci",
  "title": "AOZ1282CI — 1.2 A Simple Buck Regulator",
  "brief": "Alpha & Omega Semiconductor AOZ1282CI EZBuck. 4.5–36 V input, 1.2 A output adjustable down to 0.8 V, 450 kHz PWM, internal 420 mΩ NMOS, SOT23-6L.",
  "version": "1.0.0",
  "tags": [],
  "license": "MIT",
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      "prompt": "What's the switching frequency of the AOZ1282CI?",
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    {
      "prompt": "What's the input voltage range of the AOZ1282CI?",
      "label": "Input range"
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    {
      "prompt": "Feedback divider formula for AOZ1282CI output voltage",
      "label": "Feedback"
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      "prompt": "What package does the AOZ1282CI come in?",
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  "component": {
    "mpn": "AOZ1282CI — 1.2 A Simple Buck Regulator",
    "manufacturer": "Alpha & Omega Semiconductor",
    "package": "",
    "pin_count": null,
    "category": "Buck Regulator",
    "subcategory": "",
    "body_size": null,
    "parts": {},
    "distributor_links": {}
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  "readme": "**Source:** [Alpha & Omega AOZ1282CI Datasheet](https://www.aosmd.com/res/data_sheets/AOZ1282CI.pdf)\n**Manufacturer:** Alpha & Omega Semiconductor\n**Part Number:** AOZ1282CI\n**Document:** Rev 1.4 — June 2022 (EZBuck™ 1.2 A Simple Buck Regulator)\n\n## Description\n\nThe AOZ1282CI is a high-efficiency, simple-to-use 1.2 A buck regulator flexible enough to be optimized for a variety of applications. The AOZ1282CI works from a 4.5 V to 36 V input voltage range and provides up to 1.2 A of continuous output current. The output voltage is adjustable down to 0.8 V. The fixed switching frequency of 450 kHz PWM operation reduces inductor size.\n\n## Key Specifications\n\n| Parameter | Value |\n| --- | --- |\n| Input Voltage Range | 4.5 V – 36 V |\n| Output Current | 1.2 A continuous |\n| Output Voltage | Adjustable down to 0.8 V |\n| Switching Frequency | 450 kHz (fixed PWM) |\n| Internal NMOS R<sub>DS(on)</sub> | 420 mΩ |\n| Efficiency | Up to 95 % |\n| Package | SOT23-6L |\n| Operating Temperature | −40 °C to +85 °C (ambient) |\n\n## Features\n\n- 4.5 V to 36 V operating input voltage range\n- 420 mΩ internal NMOS\n- Up to 95 % efficiency\n- Internal compensation\n- 1.2 A continuous output current\n- Fixed 450 kHz PWM operation\n- Internal soft start\n- Output voltage adjustable down to 0.8 V\n- Cycle-by-cycle current limit\n- Short-circuit protection\n- Thermal shutdown\n- Small-size SOT23-6L package\n\n## Applications\n\n- Telecom / Networking / Datacom equipment\n- Point-of-load DC/DC conversion\n- Set-top boxes and cable modems\n- DVD drives and HDDs\n- LCD monitors and TVs\n\n## Pin Configuration\n\nPackage: SOT23-6L (Top View).\n\n| Pin | Name | Function |\n| --- | --- | --- |\n| 1 | BST | Bootstrap Voltage Input. High-side driver supply. Connect a 100 nF capacitor between BST and LX. |\n| 2 | GND | Ground |\n| 3 | FB | Feedback Input. Regulated to 0.8 V. Used to set the PWM output voltage via a resistor divider between the output and GND. |\n| 4 | EN | Enable Pin. Active high. Connect EN pin to VIN through a current-limiting resistor. Do not leave EN floating. |\n| 5 | VIN | Supply Voltage Input. 4.5 V to 36 V. When VIN rises above the UVLO threshold, the device starts up. |\n| 6 | LX | PWM Output. Connect to inductor. |\n\n## Absolute Maximum Ratings\n\nExceeding the Absolute Maximum Ratings may damage the device.\n\n| Parameter | Rating | Units |\n| --- | --- | --- |\n| Supply Voltage (V<sub>IN</sub>) | 40 | V |\n| LX to GND | −0.7 to V<sub>IN</sub>+0.3 | V |\n| LX to GND transient, < 10 ns | −3 | V |\n| EN to GND | −0.3 to 40 | V |\n| FB to GND | −0.3 to 6 | V |\n| BST to GND | V<sub>LX</sub> + 6 | V |\n| Junction Temperature (T<sub>J</sub>) | +150 | °C |\n| Storage Temperature (T<sub>S</sub>) | −65 to +150 | °C |\n| ESD Rating (HBM, 1.5 kΩ + 100 pF) | 2 | kV |\n\n## Recommended Operating Conditions\n\n| Parameter | Rating |\n| --- | --- |\n| Supply Voltage (V<sub>IN</sub>) | 4.5 V to 36 V |\n| Output Voltage (V<sub>OUT</sub>) | 0.8 V to 0.85×V<sub>IN</sub> |\n| Ambient Temperature (T<sub>A</sub>) | −40 °C to +85 °C |\n| Package Thermal Resistance (θ<sub>JA</sub>) | 220 °C/W (SOT23-6L) |\n\n## Electrical Characteristics\n\nT<sub>A</sub> = 25 °C, V<sub>IN</sub> = 12 V, unless otherwise specified. **Bold** indicates temperature range of −40 °C to +85 °C.\n\n| Parameter | Symbol | Conditions | Min | Typ | Max | Units |\n| --- | --- | --- | --- | --- | --- | --- |\n| Supply Voltage | V<sub>IN</sub> | | **4.5** | | **36** | V |\n| Input Under-Voltage Lockout Threshold | V<sub>UVLO</sub> | V<sub>IN</sub> rising / falling | **2.3** | 2.9 | | V |\n| UVLO Hysteresis | V<sub>UVLO_HYS</sub> | | | 260 | | mV |\n| Quiescent Supply Current | I<sub>IN</sub> | I<sub>OUT</sub> = 0, FB = 1 V, EN > 1.2 V | | 1 | **1.5** | mA |\n| Shutdown Supply Current | I<sub>OFF</sub> | EN = 0 V | | | **8** | µA |\n| Feedback Voltage | V<sub>FB</sub> | | 784 | 800 | 816 | mV |\n| Load Regulation | V<sub>FB_LOAD</sub> | 0.12 A < Load < 1.08 A | | 0.5 | | % |\n| Line Regulation | V<sub>FB_LINE</sub> | Load = 600 mA | | 0.03 | | %/V |\n| FB Input Current | I<sub>FB</sub> | FB = Regulation | | | 500 | nA |\n| EN Input Threshold (Off) | V<sub>EN_OFF</sub> | Off threshold | | | **0.4** | V |\n| EN Input Threshold (On)  | V<sub>EN_ON</sub>  | On threshold  | **1.2** | | | V |\n| EN Input Hysteresis | V<sub>EN_HYS</sub> | | | 200 | | mV |\n| EN Input Current | I<sub>EN</sub> | | | | **3** | µA |\n| Switching Frequency | f<sub>O</sub> | | 360 | 450 | 540 | kHz |\n| Maximum Duty Cycle | D<sub>MAX</sub> | | | 87 | | % |\n| Minimum On Time | t<sub>ON_MIN</sub> | | | 150 | | ns |\n| Current Limit | I<sub>LIM</sub> | | 1.5 | 1.9 | | A |\n| Thermal Shutdown Limit (T<sub>J</sub> rising) | T<sub>SD</sub> | | | 150 | | °C |\n| Thermal Shutdown Limit (T<sub>J</sub> falling) | | | | 110 | | °C |\n| Soft-Start Interval | t<sub>SS</sub> | | | 1.5 | | ms |\n| NMOS Leakage | I<sub>LEAKAGE</sub> | EN = 0, LX = 0 | | | 10 | µA |\n| NMOS On-Resistance | R<sub>DS(on)</sub> | | | 420 | | mΩ |\n\n## Key Formulas\n\nFeedback divider sets output voltage:\n\n$$V_{OUT} = 0.8\\text{ V} \\times \\left(1 + \\frac{R_1}{R_2}\\right)$$\n\nOutput capacitor ripple (low-ESR ceramic):\n\n$$\\Delta V_{OUT} \\approx \\frac{\\Delta I_L}{8 \\times f \\times C_O}$$\n\nTotal power dissipation (conduction-loss dominated):\n\n$$P_{total\\_loss} = (V_{IN} \\times I_{IN}) - (V_{OUT} \\times V_{IN})$$\n\n## Applications\n\n- Typical application: the Figure 1 reference circuit uses an external inductor L, output capacitor C<sub>2</sub>, bootstrap capacitor C<sub>3</sub>, and feedback resistors R<sub>1</sub>/R<sub>2</sub>. Enable pin should be driven by VIN through a current-limiting resistor.\n- Output-capacitor selection: use ceramic (X5R/X7R) capacitors for low ESR and tight ripple; low-ESR tantalum or aluminum electrolytic also work.\n- Layout: the two high-current loops — input path VIN→C₁→switch and output path LX→L→C<sub>OUT</sub>→Schottky — should both be kept tight to minimize noise and improve efficiency.\n",
  "author": {
    "id": "695820315b5f1e4db2fcf602",
    "name": "Kyle Bergstedt",
    "email": "[email protected]"
  },
  "visibility": {
    "public": true
  },
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  "metadata": {},
  "created_at": "2026-05-28T05:36:51.958Z",
  "updated_at": "2026-05-28T05:36:51.958Z"
}