TS2940CW33RP - 1A 3.3V Ultra-Low Dropout LDO | Taiwan Semiconductor
MPN: TS2940CW33RP ✓ Hoạt độngTS2940CW33RP Tóm tắt
An LDO (Low-Dropout) linear regulator is a type of voltage regulator that maintains a stable, low-ripple output voltage even when the input-to-output differential is very small - as little as a few hundred millivolts. LDOs sit beneath the broader hierarchy of linear regulators, themselves a subset of voltage regulators in the power-management IC family. Unlike switching converters, LDOs dissipate the excess input-to-output energy as heat, so they trade efficiency for exceptionally low output noise and zero switching ripple, a combination valuable for analog and RF rails.
The TS2940C family features 100 uA typical quiescent current, a PNP pass architecture that allows the regulator to operate from inputs as low as ~3.9 V while still regulating 3.3 V out, and very low ground current that rises only slightly at dropout, extending battery life. The SOT-223 package with an exposed tab keeps the part compact while providing adequate thermal dissipation for continuous 1 A operation in moderate VIN/VOUT differential conditions.
The architecture is a monolithic bipolar design with an internal bandgap reference, error amplifier, and PNP pass transistor. Quiescent current is well-controlled and the device tolerates a wide 0 V to 35 V input range, which simplifies protection design and allows direct connection to higher-voltage rails such as 12 V automotive or industrial buses with appropriate input filtering.
Typical applications include battery-powered equipment, post-regulator noise filters after switching converters, microcontroller and logic-rail supplies, and 3.3 V point-of-load regulation in industrial and consumer systems. The fixed 3.3 V output makes it a near-direct match for 3.3 V MCUs, MCUs, Wi-Fi modules, and 3.3 V-only logic families.
When designing with this part, mind the thermal budget: at 1 A load the dropout region can dissipate several hundred milliwatts or more, so a copper pour on the SOT-223 tab is recommended. Also note that the 0 V minimum input is the absolute rating - in practice a 4 V VIN minimum is needed to maintain 3.3 V regulation across temperature.
This page synthesizes distributor pricing, drop-in alternatives, application notes, and design considerations not found in the manufacturer datasheet alone.
Bộ thay thế dễ dàng lắp đặt cho TS2940CW33RP — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với TS2940CW33RP (cùng hình factor và footprint) — khác nhau ở Input Voltage Range, Output Voltage, Package, RoHS Status.
TS2940CW33
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →TS2940CW50RP
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
TS2940CW25RP
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
LM2940CS-3.3
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MIC2940A-3.3WU
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LT1129CST-3.3
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
TS2940CW33RP Tỷ lệ tối đa & tính chất điện
| Regulator Type | Low Dropout (LDO), Fixed |
| Output Polarity | Positive |
| Điện áp đầu ra | 3.3 V (fixed, 3.2 V to 3.4 V tolerance) |
| Điện áp tối đa đầu ra | 1 A |
| Phạm vi điện áp đầu vào | 0 V to 35 V |
| Dropout Voltage (typ) | 600 mV at 1 A full load |
| Quiescent Current (typ) | 100 uA |
| Ground Current at Dropout | Increases only slightly (extending battery life) |
| Maximum Voltage Tolerance | 3 % |
| Hộp | SOT-223, 3 pins |
| Terminal Form | Gull Wing |
| Kiểu lắp đặt | Surface Mount |
| Trạng thái RoHS | Compliant (per distributor listing) |
Cấu hình chân TS2940CW33RP
| Chân 1 | VIN — Input voltage supply (0 V to 35 V) |
| Chân 2 | GND — Ground reference |
| Chân 3 | VOUT — Regulated output, fixed 3.3 V |
| Chân TAB | TAB — Exposed thermal pad - solder to PCB for thermal dissipation |
Ứng dụng tiêu biểu
TS2940CW33RP phù hợp cho 6 Áp dụngs: Battery-Powered 3.3V Rail, Post-Switching-Converter Noise Filter, Industrial 24V-to-3.3V Point-of-Load, Microcontroller 3.3V Supply, Automotive 12V-to-3.3V Subsystem, Embedded Sensor Module Power.
Battery-Powered 3.3V Rail
The TS2940CW33RP's 600 mV typical dropout and 100 uA quiescent current extend battery life in 3.3 V portable systems supplied by 3.6 V Li-ion or 3.0 V Li-primary cells. At VIN = 3.6 V and 1 A load the part dissipates only 300 mW (versus several watts for a 12 V-to-3.3 V buck), enabling compact SOT-223 placement near the battery with minimal thermal rise. Compared to higher-Iq LDOs, the slightly-increased current at dropout preserves runtime rather than collapsing it - directly addressing the 'low-battery squeeze' that ends portable sessions early.
Được đề xuất
Post-Switching-Converter Noise Filter
Place the TS2940CW33RP downstream of a switching converter (e.g., 5 V or 12 V buck) to strip switching ripple from a 3.3 V digital rail. Unlike the buck's switching noise in the 50 to 500 kHz range, the TS2940 contributes zero switching ripple and only ~thermal noise, suitable for noise-sensitive 3.3 V digital loads (Wi-Fi, BLE, MCU). Power dissipation is dominated by the buck's residual ripple times load, not the LDO's VIN-VOUT drop, so thermal design is straightforward. This two-stage topology is standard in IoT and embedded designs where one regulator cannot meet all efficiency AND noise requirements.
Được đề xuất
Industrial 24V-to-3.3V Point-of-Load
The TS2940CW33RP's 0 V to 35 V absolute input range allows direct connection to 24 V industrial bus rails with adequate input filtering (TVS + capacitor). At 24 V to 3.3 V and 1 A, dissipation is ~20.7 W - exceeding the SOT-223 envelope - so this path is best at light loads (up to ~200 mA for 1 W dissipation and ~25 C rise above ambient). For higher current at 24 V input, choose a switching pre-regulator. At 12 V VIN and 3.3 V at 500 mA (typical industrial sensor load), the part dissipates 4.35 W - use a substantial copper pour on the SOT-223 tab.
Được đề xuất
Microcontroller 3.3V Supply
The TS2940CW33RP delivers a clean 1 A 3.3 V rail sized for typical 32-bit MCU + Wi-Fi/BLE module loads (peak ~600 mA, average ~150 mA). With 4 V minimum input (3.3 V plus dropout), the part can be fed from a USB 5 V rail or 3.6 V Li-ion with margin. The 100 uA quiescent is negligible compared to the MCU's active draw, but matters in standby/deep-sleep where the MCU drops to microamps and the LDO Iq becomes a non-negligible share of total battery drain.
Được đề xuất
Automotive 12V-to-3.3V Subsystem
While the TS2940CW33RP itself is not AEC-Q100 qualified, it can be used in non-safety automotive subsystems (infotainment peripherals, body controllers) fed from a 12 V bus with TVS protection at VIN. At 12 V to 3.3 V at 250 mA typical load, dissipation is 2.18 W - manageable with a 1 square inch copper pour yielding about 25 C rise. For safety-critical (ADAS, ECU) rails, choose an AEC-Q100 alternative such as TPS7A2450DBVR (5 V) or similar automotive-grade LDO.
Được đề xuất
Embedded Sensor Module Power
The TS2940CW33RP provides a 3.3 V rail for sensor modules (IMU, temperature, pressure) requiring low-noise supply to preserve measurement accuracy. Its 100 uA quiescent and 600 mV dropout allow 3.6 V Li-ion primary or rechargeable cells to power the sensor continuously for thousands of hours. The fixed 3.3 V output matches the common logic level for modern sensor ICs, eliminating resistor dividers. Place 1 uF ceramic + 10 uF tantalum at VOUT for sensor transient suppression.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho TS2940CW33RP — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | TS2940CW33 | LM2940CS-3.3 | MIC2940A-3.3WU | LT1129CST-3.3 |
|---|---|---|---|---|---|
| Brand | Taiwan Semiconductor | Taiwan Semiconductor | Texas Instruments | Microchip Technology | Analog Devices |
| Package | SOT-223 (CW) | SOT-223 - same | SOT-223 - same | SOT-223 - same | SOT-223 - same |
| Output Voltage | 3.3 V fixed | 3.3 V fixed | 3.3 V fixed | 3.3 V fixed | 3.3 V fixed |
| Maximum Output Current | 1 A | 1 A | 1 A | 1 A | 0.7 A |
| Input Voltage Range | 0 V to 35 V | 0 V to 35 V | -0.3 V to 26 V | 0 V to 26 V | -0.3 V to 30 V |
| Dropout Voltage (typ) | 600 mV at 1 A | 600 mV at 1 A | 500 mV at 1 A | 450 mV at 1 A | 400 mV at 0.7 A |
| RoHS Status | Compliant | Compliant | Compliant | Compliant | Compliant |
| Unit Price (1 pc, USD) | 0.95 | 0.95 | 1.40 | 1.25 | 3.85 |
Bảo phân biệt quan trọng
- Lowest-cost 1 A LDO in 3.3 V fixed SOT-223 (vsLM2940CS-3.3)
- Lower quiescent current than legacy LM2940 (vsLM2940CS-3.3)
- Wider 35 V input range than LT1129 and MIC2940 (vsLT1129CST-3.3, MIC2940A-3.3WU)
Ghi chú thiết kế
Estimated: at VIN=12 V, VOUT=3.3 V, IOUT=1 A the TS2940CW33RP dissipates (12-3.3)*1 = 8.7 W. The SOT-223 package alone cannot safely dissipate this; a previous calculation using 31 C/W theta_JA would yield a junction temperature rise of ~270 C above ambient, exceeding the maximum junction rating. A switching pre-regulator (e.g., 5 V buck) is required for 12 V to 3.3 V 1 A applications. At 5 V VIN and 3.3 V at 1 A, dissipation drops to 1.7 W, manageable with a 1 square inch copper pour on the exposed tab yielding ~30 C rise.
Solder the SOT-223 exposed tab to a copper pour of at least 1 square inch (645 mm^2) on the top or bottom layer for thermal relief. Use thermal vias to channel heat into inner layers. Place input bypass (1 uF to 10 uF ceramic + 10 uF tantalum) within 5 mm of the VIN pin, and output capacitor (10 uF to 22 uF tantalum or low-ESR ceramic) within 5 mm of VOUT. Layout grounds as a star with VIN-ground return and load-ground return joining at the GND pin.
Do not connect VIN to voltages above 35 V - this is the absolute maximum and any transient above this destroys the part. Add a TVS (e.g., SMBJ33A) for 24 V industrial-bus applications. The output capacitor's ESR affects loop stability; avoid ultra-low-ESR ceramics (under 10 mOhm) unless specified in the datasheet. Do not assume 0 V is a normal operating input - in practice, ~4 V is the minimum for full 3.3 V regulation under all load conditions.
Estimated: the TS2940CW33RP's 100 uA quiescent current consumes 0.33 mW at 3.3 V - negligible for most applications, but in a 1 mA deep-sleep IoT node the LDO Iq represents up to 10 percent of total standby drain. For ultra-low-power designs with sub-100 uA standby targets, consider a separate low-Iq LDO (e.g., TPS7A02) for the always-on rail. For typical MCU active loads (10 mA to 100 mA), this LDO's Iq is a tiny fraction of total power and remains the right choice.
Thông tin tuân thủ
RoHS compliance per distributor listing (Vyrian digchip datasheet). REACH, halogen-free, and conflict-mineral declarations are not published on the verified sources and should be confirmed with Taiwan Semiconductor directly for production-grade procurement.
