MC33063AD - 1.5A Buck/Boost/Inverting DC-DC Converter | Texas Instruments
MPN： MC33063AD ✓ 啟用中MC33063AD 概覽
A switching regulator is a power management IC that converts one DC voltage to another by repeatedly switching energy through an inductor, then filtering with capacitors. The MC33063AD belongs to the SMPS controller family (switched-mode power supply) -> DC-DC converter -> voltage regulator -> power management IC -> semiconductor. Compared to linear regulators, switching converters like the MC33063AD achieve 70-95% efficiency even at large input-to-output voltage deltas, making them ideal when thermal dissipation must be minimized or when the input voltage is much higher than the output.
Key features include a 1.5A peak switch current rating, an adjustable output voltage down to 1.25V, internal current limiting via a single external resistor, and an external resistor-programmable oscillator frequency from approximately 100 Hz to 100 kHz. The 8-SOIC package provides standard surface-mount manufacturability and is footprint-compatible with the MC34063A (commercial 0-70C) and MC33063ADG (onsemi second source).
Architecturally, the device uses a bipolar Darlington output switch, a transconductance error amplifier referenced to the internal 1.25V bandgap, and a flip-flop synchronized to the on-chip oscillator. This classic 1970s architecture remains popular because the design requires only a handful of external parts (inductor, capacitor, diode, sense resistor, feedback divider) and provides predictable behavior across a wide input range.
Typical applications include cost-sensitive step-down converters for 12V/24V industrial buses, boost converters for battery-powered systems needing 5V or higher rails, and negative-voltage inverters for op-amp and analog signal-chain supplies. The internal switch and current limit also make it suitable for LED drivers and simple motor speed controllers operating from single-cell Li-ion or multi-cell lead-acid sources.
When designing with the MC33063AD, ensure the inductor saturation current exceeds the internal current-limit threshold, and verify that the catch diode reverse voltage rating exceeds the maximum input supply. PCB layout should keep the switch-current loop (pin 1, inductor, catch diode) compact to minimize switching noise.
This page synthesizes distributor pricing, drop-in alternatives from TI and onsemi, and practical design notes not consolidated in the manufacturer datasheet.
直接替換替代品，適用於 MC33063AD — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： MC33063AD （相同外形與佔位） — 差異在於 MSL Level, Operating Temperature, Package, Topology.
MC33063ADR
✅ 直接替換聯絡詢價
查看資料表 →MC34063AD
✅ 直接替換📋 參考替代品（不在目錄中）
MC34063ADR
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
MC33063ADG
✅ 直接替換📋 參考替代品（不在目錄中）
MC33063ADG
✅ 直接替換📋 參考替代品（不在目錄中）
MC34063ADG
✅ 直接替換📋 參考替代品（不在目錄中）
MC33063AD 最大額定值與電氣特性
| 拓撲 | Buck, Boost, Inverting (Step-Down/Up/Reverse) |
| 輸入電壓範圍 | 3 V to 40 V |
| 輸出電壓範圍 | 1.25 V to 40 V (adjustable) |
| Output Current (Switch) | 1.5 A peak |
| Switch Type | Internal Darlington NPN |
| 參考電壓 | 1.25 V (internal bandgap) |
| Oscillator Frequency | Up to 100 kHz (externally programmable) |
| Duty Cycle (max) | approx. 80% (buck/boost), 100% (inverting) |
| 工作溫度 | -40 C to +85 C (industrial) |
| 封裝 | 8-pin SOIC (D), 3.90 mm width |
| 安裝類型 | Surface Mount |
| MSL 等級 | 1 (unlimited floor life) |
| RoHS 狀態 | Compliant |
| 電流限制 | Internally programmable via external resistor |
MC33063AD 腳位配置
| 腳位 1 | SCw/SwK — Switch collector (Darlington output switch collector) |
| 腳位 2 | SCe/SwE — Switch emitter (Darlington output switch emitter) |
| 腳位 3 | TC — Timing capacitor (sets oscillator frequency) |
| 腳位 4 | GND — Ground |
| 腳位 5 | CII — Comparator inverting input |
| 腳位 6 | Vfb — Feedback (1.25V internal reference) |
| 腳位 7 | Ipk — Peak current sense (current limit programming) |
| 腳位 8 | VCC — Supply voltage (3V to 40V) |
典型應用
MC33063AD 適用於 6 應用s: 12V/24V Industrial Buck Converter, Boost Converter for 5V to 12V Supply, Negative Voltage Inverter, Battery-Powered LED Driver, Automotive 12V Acessory Power (Non-Safety), Low-Cost DC Motor Speed Controller.
12V/24V Industrial Buck Converter
The MC33063AD fits 24V industrial bus step-down designs where 5V or 3.3V rails are needed for microcontroller and sensor power. Its 3V-40V input range directly accepts 24V industrial supply rails, and the 1.5A peak switch current delivers up to 750mA continuous at 12V-to-5V conversion. According to the TI datasheet, a typical 12V-to-5V buck implementation requires only an inductor (100uH), catch diode (Schottky 20V/2A), 470pF timing capacitor, and a feedback divider of 3.9k/1.2k. The 100 kHz oscillator allows modest inductor size. Place the switch-current loop (pin 1, inductor, diode) compactly to minimize EMI on noisy industrial PCBs.
推薦
Boost Converter for 5V to 12V Supply
The MC33063AD is well-suited as a step-up converter to generate 12V rails from 5V USB or battery sources for op-amp analog supplies or RS-232 drivers. With its adjustable output up to 40V and 1.5A switch, the device delivers approximately 200-400mA continuous at 5V-to-12V conversion depending on inductor selection. The TI datasheet typical boost application uses a 120uH inductor with saturation current above 1.5A, a Schottky catch diode rated for at least 20V reverse, and a feedback divider of 22k/2.4k for 12V output. The industrial -40C to +85C rating enables outdoor and automotive-cabin environments.
推薦
Negative Voltage Inverter
The MC33063AD produces negative output voltages by reconfiguring the inductor and capacitor connections - a key topology advantage over single-function regulators. A -12V output from +5V input uses a 100uH inductor, a Schottky catch diode, and a feedback divider referenced to the negative rail. The internal oscillator and current limit apply identically to the inverting configuration. This makes the MC33063AD ideal for op-amp dual supplies, RS-232 charge-pump backup rails, and instrumentation bias generators. Efficiency typically reaches 75-85% at moderate loads, superior to linear-based inverting designs.
推薦
Battery-Powered LED Driver
The MC33063AD drives strings of LEDs from a single-cell Li-ion or multi-cell lead-acid battery through its boost configuration. With up to 40V output and 1.5A peak switch current, the part can drive 6-10 white LEDs in series from a 3.7V Li-ion source. The internal 1.25V reference sets LED current via a sense resistor in series with the LED load. Pulse-width modulation by the internal PWM controller maintains regulation as battery voltage sags. The 100 kHz oscillator allows compact inductors while keeping switching losses manageable.
推薦
Automotive 12V Acessory Power (Non-Safety)
The MC33063AD handles 12V automotive accessories such as interior lighting, dashboard fan injectors, and aftermarket infotainment supplies where AEC-Q100 is not mandated. Its 40V input withstands load-dump transients up to 36V typical, and the -40C to +85C industrial range covers cabin temperatures. For safety-critical or under-hood applications above 85C, the AEC-Q100-qualified TPS5430 or TPS54360 should be substituted. The MC33063AD remains a cost-effective solution for non-safety in-cabin electronics where reliability and BOM count matter.
推薦
Low-Cost DC Motor Speed Controller
The MC33063AD drives small DC brushed motors as a variable duty-cycle buck, with feedback taken from the motor back-EMF or a current-sense resistor. With 1.5A peak switch and 40V rating, the part handles motors up to 30V at 1A continuous, useful for toys, small pumps, and ventilation fans. PWM control of the inductor current gives smooth speed adjustment at the oscillator's 25-100 kHz range, well above audible noise. Forward/reverse operation requires an H-bridge external to the regulator.
推薦
推薦產品摘要
工程參考資料，適用於 MC33063AD — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | MC33063ADR | MC34063AD | MC34063ADR | MC33063ADG | MC34063ADG |
|---|---|---|---|---|---|---|
| Package | 8-SOIC (D) | 8-SOIC (D) - same | 8-SOIC (D) - same | 8-SOIC (D) - same | 8-SOIC (D) - same | 8-SOIC (D) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | onsemi | onsemi |
| Input Voltage Range | 3 V to 40 V | 3 V to 40 V | 3 V to 40 V | 3 V to 40 V | 3 V to 40 V | 3 V to 40 V |
| Peak Switch Current | 1.5 A | 1.5 A | 1.5 A | 1.5 A | 1.5 A | 1.5 A |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | 0 C to +70 C | 0 C to +70 C | -40 C to +85 C | 0 C to +70 C |
| Topology Support | Buck/Boost/Inverting | Buck/Boost/Inverting | Buck/Boost/Inverting | Buck/Boost/Inverting | Buck/Boost/Inverting | Buck/Boost/Inverting |
| Oscillator Frequency (max) | 100 kHz | 100 kHz | 100 kHz | 100 kHz | 100 kHz | 100 kHz |
| AEC-Q100 Qualified | No | No | No | No | No | No |
| Approx. Unit Price (qty 1) | USD 0.78 | USD 0.78 (reel) | USD 0.65 | USD 0.65 (reel) | USD 0.55 | USD 0.50 |
主要差異化特點
- Wide 3V-40V input accepts 24V industrial buses directly (對比LM2574/LM2594 buck regulators (40V max on LM2594HV only, vs the MC33063AD's standard 40V rating))
- Single-IC solution for buck, boost, and inverting topologies (對比TPS5430 (buck only) or TPS61040 (boost only) - separate part required for each topology)
- Industrial -40C to +85C temperature range vs commercial 0-70C (對比MC34063AD (commercial 0-70C))
- Onsemi second source for supply-chain redundancy (對比Single-source TI MC33063AD)
設計說明
Keep the high-current loop (pin 1 switch collector, inductor, catch diode, ground return) physically small - ideally within 1 square centimeter - to minimize parasitic inductance and radiated EMI. The MC33063AD's 100 kHz edge rate can inject substantial noise into analog circuits if the switch loop is not compact. A ground pour under the IC connected to pin 4 helps dissipate switching heat and provides a low-impedance return.
Estimated: At VIN=24V, VOUT=5V, IOUT=500mA, the MC33063AD's internal Darlington switch dissipates roughly (24V-5V)*0.5A = 9.5W of switching and dropout losses combined (with efficiency ~80%). The 8-SOIC package's thermal resistance (theta-JA ~150 C/W on a standard JEDEC 4-layer board) gives a junction temperature rise of ~190C above ambient. A minimum 1 square inch copper pour on the GND pin and adequate airflow are required for sustained 5W+ dissipation. Drop to VIN=12V for the same load and dissipation drops to ~4.5W.
Common pitfalls: (1) Inductor saturation current must exceed the programmed current-limit threshold by at least 20%, or efficiency plummets; (2) the catch diode must be Schottky with reverse voltage rating above maximum input supply (MUST be >40V for 24V bus designs); (3) the feedback divider MUST use 1% or better resistors for output voltage accuracy; (4) the timing capacitor Ct MUST be placed close to pin 3 with short traces to avoid oscillator jitter; (5) do NOT exceed the maximum oscillator frequency of 100 kHz or the Darlington switch transition losses dominate efficiency.
合規資訊
RoHS compliant per TI product page. Lead-free / halogen-free per TI packaging material declarations. NOT AEC-Q100 qualified - this is industrial grade only. onsemi MC33063ADG is also RoHS compliant and offers an authorized second-source.
