TS2940CW33RP - 1A 3.3V Ultra-Low Dropout LDO | Taiwan Semiconductor
N.º de pieza: TS2940CW33RP ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $0.95 | $0,95 |
| 10 | $0.82 | $8,20 |
| 100 | $0.68 | $68,00 |
| 500 | $0.55 | $275,00 |
| 1.000 | $0.42 | $420,00 |
TS2940CW33RP Descripción general
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.
Alternativas directas para TS2940CW33RP — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con TS2940CW33RP (mismo factor de forma y huella) — difiere en Input Voltage Range, Output Voltage, Package, RoHS Status.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
TS2940CW33
✅ Sustitución directa ⚠️ Especificaciones sin verificar✓ En stock
$0.18 / unidad
Ver hoja de datos →TS2940CW50RP
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
TS2940CW25RP
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
LM2940CS-3.3
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MIC2940A-3.3WU
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
LT1129CST-3.3
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
TS2940CW33RP Valores máximos y características eléctricas
| Regulator Type | Low Dropout (LDO), Fixed |
| Output Polarity | Positive |
| Tensión de salida | 3.3 V (fixed, 3.2 V to 3.4 V tolerance) |
| Corriente de salida máxima | 1 A |
| Rango de tensión de entrada | 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 % |
| Encapsulado | SOT-223, 3 pins |
| Terminal Form | Gull Wing |
| Tipo de montaje | Surface Mount |
| Estado RoHS | Compliant (per distributor listing) |
Configuración de pines de TS2940CW33RP
| Pin 1 | VIN — Input voltage supply (0 V to 35 V) |
| Pin 2 | GND — Ground reference |
| Pin 3 | VOUT — Regulated output, fixed 3.3 V |
| Pin TAB | TAB — Exposed thermal pad - solder to PCB for thermal dissipation |
Aplicaciones típicas
TS2940CW33RP es adecuado para 6 aplicacións: 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.
Recomendado
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.
Recomendado
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.
Recomendado
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.
Recomendado
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.
Recomendado
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.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para TS2940CW33RP — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | 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 |
Diferenciadores clave
- Lowest-cost 1 A LDO in 3.3 V fixed SOT-223 (frente a LM2940CS-3.3)
- Lower quiescent current than legacy LM2940 (frente a LM2940CS-3.3)
- Wider 35 V input range than LT1129 and MIC2940 (frente a LT1129CST-3.3, MIC2940A-3.3WU)
Notas de diseño
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.
Información de cumplimiento
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.
