BCR431UXTSA1 - 36.5mA Linear LED Driver, 42V | Infineon
MPN： BCR431UXTSA1 ✓ 啟用中BCR431UXTSA1 概覽
A linear LED driver (also called an LED current regulator or constant-current sink) is a type of power management IC that delivers a regulated current to a string of one or more LEDs. Linear drivers sit within the broader hierarchy of power management semiconductors: linear LED driver -> constant-current regulator -> LED driver -> power management IC. They are preferred over switching LED drivers in applications requiring low EMI, small PCB area, and minimum BOM cost.
Key features of the BCR431UXTSA1 include its 36.5 mA preset output current with ±10% tolerance across the full operating range, a wide 1.4 V to 42 V supply input range, low headroom voltage of typically 0.6 V, and integrated reverse-polarity protection at the output. The SOT23-6 footprint occupies less than 9 mm² of board space, allowing placement close to the LED load.
Architecturally, the BCR431UXTSA1 uses a high-side current-mirror reference and an integrated bipolar pass transistor to regulate the output current. This topology keeps the LED cathode referenced to ground, simplifying heatsinking and PCB layout. Because the device is a linear controller, thermal dissipation equals (VIN - VLED_STACK) x IOUT, so engineers must budget the SOT23-6 31 C/W θJA accordingly.
Typical applications include small LED signs, channel-letter illumination, architectural cove lighting, and 24 V industrial signaling strips where EMI from switchers must be avoided. The 42 V input ceiling also suits 36 V industrial bus rails. When designing with the BCR431UXTSA1, ensure that the worst-case VIN - VLED total stays below the 42 V absolute maximum and that the SOT23-6 power dissipation does not exceed the thermal envelope. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
直接替換替代品，適用於 BCR431UXTSA1 — 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。
BCR432UXTSA1
✅ 直接替換📋 參考替代品（不在目錄中）
BCR430UXTSA1
✅ 直接替換📋 參考替代品（不在目錄中）
BCR431UE6327XTSA1
✅ 直接替換📋 參考替代品（不在目錄中）
BCR431UXTSA1XTSA1
✅ 直接替換📋 參考替代品（不在目錄中）
BCR431UW3XTSA1
✅ 直接替換📋 參考替代品（不在目錄中）
BCR431UXTSA1 最大額定值與電氣特性
| Product Type | Linear LED Driver / Constant-Current Regulator |
| 輸出數量 | 1 |
| 拓撲 | Linear |
| Dimming | No Dimming |
| Output Current | 36.5 mA (preset) |
| 輸入電壓範圍 | 1.4 V to 42 V |
| Headroom Voltage | 0.6 V (typical) |
| 封裝 | PG-SOT23-6 |
| 安裝類型 | Surface Mount |
| RoHS 狀態 | Compliant |
| Reverse Polarity Protection | Yes (integrated) |
BCR431UXTSA1 腳位配置
| 腳位 1 | VS — Supply voltage input (1.4 V to 42 V) |
| 腳位 2 | GND — Ground reference |
| 腳位 3 | OUT — LED cathode connection (constant-current sink output) |
| 腳位 4 | NC — Not connected (per datasheet) |
| 腳位 5 | NC — Not connected (per datasheet) |
| 腳位 6 | NC — Not connected (per datasheet) |
典型應用
BCR431UXTSA1 適用於 6 應用s: Channel Letter LED Signage, Architectural Cove Lighting, Industrial 24V Signaling Strips, LED Backlight for Small Displays, Automotive Interior LED Lighting, Decorative String Lights.
Channel Letter LED Signage
The BCR431UXTSA1 drives individual LED modules inside illuminated channel letters where 24 V power feeds are common. Its 42 V input ceiling tolerates 24 V industrial rail transients, while the 36.5 mA preset current matches the typical forward current of medium-power white LEDs. Placing one driver per 1 to 3 LEDs keeps brightness uniform across long letter runs.
推薦
Architectural Cove Lighting
Architectural cove lighting requires a slim, low-EMI driver that fits in a narrow aluminum extrusion. The BCR431UXTSA1's PG-SOT23-6 footprint (under 9 mm²) and linear topology (no inductor, no switching noise) make it ideal for placing one driver per LED cluster in continuous cove runs fed by 24 V or 36 V supplies.
推薦
Industrial 24V Signaling Strips
Factory-floor status strips run on 24 V industrial rails and demand a rugged, EMI-quiet driver. The BCR431UXTSA1's 1.4 V to 42 V input range absorbs 24 V rail transients without external protection, and its linear operation produces no conducted or radiated noise that could couple into nearby sensor cables.
推薦
LED Backlight for Small Displays
Compact LCD and TFT backlights in appliances and instrumentation benefit from the BCR431UXTSA1's tiny footprint and stable 36.5 mA drive. With one driver per LED string, brightness uniformity is preserved across the panel, and the linear topology avoids the EMI that could interfere with the display's column driver signals.
推薦
Automotive Interior LED Lighting
Although the standard BCR431UXTSA1 is industrial-grade, the same die is available in an automotive-qualified variant. The 42 V load-dump-tolerant input and integrated reverse-polarity protection suit door-pocket, footwell, and ambient lighting strips fed from the 12 V automotive bus, with the linear driver ensuring no switcher ripple reaches audio circuits.
推薦
Decorative String Lights
Seasonal and architectural string lights use long LED strings on a single 24 V or 36 V supply. The BCR431UXTSA1's 36.5 mA preset matches common 5 mm through-hole LEDs, and its 42 V ceiling supports up to 12 LEDs in series per driver, simplifying wiring and reducing the number of drivers required per string.
推薦
推薦產品摘要
工程參考資料，適用於 BCR431UXTSA1 — 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 | BCR432UXTSA1 | BCR430UXTSA1 | BCR431UE6327XTSA1 | BCR431UW3XTSA1 |
|---|---|---|---|---|---|
| Brand | Infineon Technologies | Infineon Technologies | Infineon Technologies | Infineon Technologies | Infineon Technologies |
| Package | PG-SOT23-6 | PG-SOT23-6 - same | PG-SOT23-6 - same | PG-SOT23-6 - same | PG-SOT23-6 - same |
| Output Current | 36.5 mA | 50 mA | 15 mA | 36.5 mA | 36.5 mA |
| Input Voltage Range | 1.4 V to 42 V | 1.4 V to 42 V | 1.4 V to 42 V | 1.4 V to 42 V | 1.4 V to 42 V |
| Topology | Linear | Linear | Linear | Linear | Linear |
| Dimming | No | No | No | No | No |
| Automotive Grade | No | No | No | No | Yes (AEC-Q100) |
主要差異化特點
- Mid-current preset in a 6-pin SOT23-6 (對比BCR430UXTSA1)
- Automotive-grade sibling available (對比BCR431UW3XTSA1)
- Linear topology eliminates EMI (對比Switching LED drivers (e.g. AL8860))
設計說明
Estimated: at VIN = 24 V and VLED stack = 18 V (6 white LEDs at 3 V each), power dissipation is (24 - 18) x 0.0365 = 0.219 W. With SOT23-6 θJA of approximately 200 C/W on a 1 oz 1 square-inch copper pour, junction rise is ~44 C, staying within the 150 C absolute maximum. For higher VIN-to-VLED differentials, increase copper area or add thermal vias to keep Tj below 125 C for derated operation.
Place the BCR431UXTSA1 as close as possible to the LED cathode to minimize the parasitic inductance and resistance of the OUT trace. Use a ground plane under the device to provide thermal spreading and a low-impedance return for the OUT current. Keep the input supply trace short and add a 100 nF ceramic decoupling capacitor close to the VS pin if the supply lead is longer than 25 mm.
Do not exceed the 42 V absolute maximum on the VS pin, including transient spikes from inductive loads on the same 24 V rail. Do not connect more LEDs in series than VIN_min minus the 0.6 V headroom allows, or the driver will fall out of regulation at low line. Avoid reversing VS and OUT, although internal reverse-polarity protection on the output limits damage to the device rather than the LEDs.
合規資訊
RoHS and REACH compliant per Infineon product page. Standard BCR431UXTSA1 is not AEC-Q100 qualified - choose BCR431UW3XTSA1 for automotive applications.
