TS2937CP33 - 500mA 3.3V Ultra-LDO Fixed Regulator TO-252 | TSC
MPN： TS2937CP33 ✓ 啟用中TS2937CP33 概覽
A fixed-voltage LDO is a type of linear voltage regulator that holds its output at a precise, factory-trimmed level even when the unregulated input is barely above the output. Within the power management hierarchy, this device sits under the LDO family, which in turn falls under linear regulators, voltage regulators, and finally the broader power management integrated circuit (PMIC) category. The fixed-output topology eliminates the external resistor divider required by adjustable LDOs, simplifying BOM, reducing quiescent leakage paths, and shrinking PCB footprint for cost-sensitive designs.
Key features include a tight output voltage tolerance of ±2%, 500 mA continuous output current, low quiescent current consumption, internal thermal shutdown, and short-circuit current limiting. The TO-252 (DPAK) package provides a low thermal resistance path through the tab to PCB copper, allowing reliable operation at higher VIN-VO deltas than smaller SOT-23 LDOs. The ultra-low dropout performance ensures full regulation even during input transients such as cold-crank events in 12 V automotive systems or USB load steps in 5 V rails.
Architecturally, the TS2937CP33 uses a monolithic bipolar process with an integrated PNP pass transistor, a bandgap reference, and error amplifier on a single die. This PNP-LDO topology delivers lower dropout than classical NPN regulators and avoids the minimum-load-current requirement common to some N-channel MOSFET-output LDOs. The result is a stable, well-behaved 3.3 V rail across the full 0-500 mA load range.
Typical applications include 12 V-to-3.3 V post-regulation in industrial PLCs, USB peripheral power, battery management in 6 V/12 V lead-acid systems, and always-on standby rails for microcontrollers and memory in white goods and metering equipment. The wide input voltage range also supports 24 V industrial bus systems with adequate headroom.
When designing with this device, ensure the input-to-output voltage differential does not cause excessive power dissipation beyond the DPAK's thermal capability. Adding a 10 uF minimum ESR-stable output capacitor close to the regulator improves transient response and ensures regulator stability as recommended in the manufacturer datasheet.
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 TS2937CP33 — 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： TS2937CP33 （相同外形與佔位） — 差異在於 Maximum Output Current, Package, Short-Circuit Protection.
TS2937CP50
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
TS2937CP33 ROG
✅ 直接替換📋 參考替代品（不在目錄中）
TS2937CP12
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LD1117S33CTR
✅ 直接替換📋 參考替代品（不在目錄中）
LM1117MP-3.3
✅ 直接替換📋 參考替代品（不在目錄中）
MIC29150-3.3WT
✅ 直接替換📋 參考替代品（不在目錄中）
TS2937CP33 最大額定值與電氣特性
| Regulator Type | Fixed Positive Linear (LDO) |
| 輸出電壓 | 3.3 V (fixed) |
| Output Voltage Tolerance | ±2% |
| 最大輸出電流 | 500 mA |
| 壓降電壓 | 170 mV typical at 500 mA |
| 工作溫度範圍 | -40 C to +125 C |
| 封裝 | TO-252 (DPAK) |
| 安裝類型 | Surface Mount |
| 輸出數量 | 1 |
| 過熱關機 | Yes (internal) |
| Short-Circuit Protection | Yes (internal current limit) |
| RoHS 狀態 | Compliant |
TS2937CP33 腳位配置
| 腳位 1 | VIN — Unregulated input voltage |
| 腳位 2 | GND — Ground reference |
| 腳位 3 | VOUT — Regulated 3.3 V output |
| 腳位 TAB | TAB — Exposed thermal pad (electrically connected to GND on standard variant) |
典型應用
TS2937CP33 適用於 6 應用s: 12V-to-3.3V Post-Regulation for Industrial PLCs, USB Peripheral 5V-to-3.3V Power Rail, Lead-Acid Battery Powered Metering, White Goods and Appliance Control Boards, Always-On Standby Rail for IoT Gateways, Automotive Aftermarket 12V Accessory Power.
12V-to-3.3V Post-Regulation for Industrial PLCs
The TS2937CP33's 500 mA continuous output and 170 mV typical dropout at full load make it a strong post-regulator after a 5 V switching converter in 24 V industrial PLC systems. With input up to 26 V tolerated and ±2% output accuracy, it delivers clean 3.3 V to logic ICs, opto-isolators, and sensor front-ends without the noise of a second switching stage. Unlike switching regulators it adds no EMI, but it dissipates more heat at high VIN-VO deltas, so thermal design matters. Pair it with a 10 uF ESR-stable output capacitor close to the VOUT pin for stable regulation.
推薦
USB Peripheral 5V-to-3.3V Power Rail
USB hosts supply 5 V with significant droop during heavy load steps. The TS2937CP33's 170 mV dropout and 500 mA output provide regulation down to 3.47 V on the input, well within USB tolerance. It powers USB-to-UART bridges, USB hubs, and embedded device MCUs that need a clean 3.3 V rail. The TO-252 (DPAK) tab provides sufficient heat-sinking for sustained 500 mA at 5 V input (about 850 mW dissipation). Place a 10 uF ceramic output capacitor adjacent to the device for optimal transient response.
推薦
Lead-Acid Battery Powered Metering
In 6 V or 12 V lead-acid battery metering equipment, the TS2937CP33 supplies 3.3 V to MCUs, RTCs, and LCD drivers. Its wide operating range down to a few hundred mV dropout extends usable battery life as cells discharge - a 6 V lead-acid battery can still deliver clean 3.3 V when its terminal voltage sags to 3.5 V under load. The -40 C to +125 C operating range supports outdoor and unheated enclosure deployments. Add reverse-battery and input-transient protection on the input pin for harsh battery environments.
推薦
White Goods and Appliance Control Boards
White-goods control boards (washing machines, dishwashers, refrigerators) typically run from a 12 V or 15 V rectified rail and need a quiet 3.3 V supply for the main MCU, user-interface logic, and sensor inputs. The TS2937CP33's fixed 3.3 V output eliminates the cost of a feedback resistor network and provides ±2% accuracy that supports touch-key and LED-display subsystems. The internal thermal shutdown and short-circuit protection are valuable in environments where motor and relay switching transients can stress the supply.
推薦
Always-On Standby Rail for IoT Gateways
IoT gateways and smart-home hubs need a low-power always-on 3.3 V rail to keep MCUs, Wi-Fi modules, and RTCs alive in standby. The TS2937CP33 fits well when the upstream rail is 5 V or higher. While its quiescent current is not as low as a nanopower LDO, its 500 mA capability handles short bursts when the Wi-Fi or sub-GHz radio wakes up. Pair it with a nanopower LDO (e.g., TPS7A2450DBVR) for the always-on domain if total quiescent must stay below 10 uA.
推薦
Automotive Aftermarket 12V Accessory Power
The TS2937CP33's -40 C to +125 C operating range and 500 mA output suit automotive aftermarket accessories such as dash cams, GPS trackers, and telematics dongles. It post-regulates a 12 V automotive battery rail (with cranking transients down to ~6 V) to a stable 3.3 V for the main MCU and modem. For OEM automotive designs requiring AEC-Q100 qualification, consider pin-compatible AEC-Q100 alternatives like the TL720M05-Q1 (5 V) or TPS7B6950-Q1 - the TS2937CP33 itself is not AEC-Q100 qualified.
推薦
推薦產品摘要
工程參考資料，適用於 TS2937CP33 — 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 | TS2937CP50 | TS2937CP33 ROG | TS2937CP12 | LD1117S33CTR | LM1117MP-3.3 | MIC29150-3.3WT |
|---|---|---|---|---|---|---|---|
| Brand | Taiwan Semiconductor | Taiwan Semiconductor | Taiwan Semiconductor | Taiwan Semiconductor | STMicroelectronics | Texas Instruments | Microchip Technology |
| Package | TO-252 (DPAK) | TO-252 (DPAK) - same | TO-252 (DPAK) - same | TO-252 (DPAK) - same | TO-252 (DPAK) - same | TO-252 (DPAK) - same | TO-252 (DPAK) - same |
| Output Voltage | 3.3 V fixed | 5.0 V fixed | 3.3 V fixed | 1.2 V fixed | 3.3 V fixed | 3.3 V fixed | 3.3 V fixed |
| Maximum Output Current | 500 mA | 500 mA | 500 mA | 500 mA | 800 mA | 800 mA | 1.5 A |
| Dropout Voltage (typical) | 170 mV at 500 mA | 170 mV at 500 mA | 170 mV at 500 mA | 170 mV at 500 mA | ~1.1 V at 800 mA | ~1.2 V at 800 mA | ~350 mV at 1.5 A |
| Output Voltage Tolerance | ±2% | ±2% | ±2% | ±2% | ±1% | ±1% | ±1% |
| Operating Temperature Range | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +85 C |
主要差異化特點
- Ultra-low dropout for a TO-252 fixed LDO (對比LD1117S33CTR)
- Same-brand family variant at 3.3 V with tape-and-reel (對比TS2937CP33 ROG)
- Higher current capability in same footprint (對比MIC29150-3.3WT)
設計說明
At VIN=5 V, VOUT=3.3 V, and 500 mA load, power dissipation is (5-3.3) × 0.5 = 0.85 W. Estimated: using the TO-252 (DPAK) typical theta_JA of ~50 C/W on a 1 sq-in copper pour, junction temperature rises about 42 C above ambient - within the 125 C limit. At VIN=12 V, dissipation becomes (12-3.3) × 0.5 = 4.35 W, requiring a much larger copper pour or external heatsink to keep Tj below 125 C.
Place the input and output capacitors as close as possible to the device pins. Use a 10 uF minimum ESR-stable output capacitor to ensure regulator stability. The exposed thermal tab should be soldered to a copper pad connected to a ground plane for proper heat dissipation. Keep high-current traces wide (at least 0.5 mm/20 mil per 100 mA) to minimize voltage drops and EMI.
Do not assume the TS2937CP33 output is 3.3 V without checking the variant suffix - the family includes fixed versions at 1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.3 V, 5.0 V, and 12 V. Reverse-battery and input-transient protection is recommended for automotive and battery applications, since the device has no internal reverse-blocking diode. Do not operate above the absolute maximum input rating (verify in the datasheet) or the internal pass transistor will be damaged.
合規資訊
RoHS and REACH compliant per Taiwan Semiconductor product page. NOT AEC-Q100 qualified - for automotive designs requiring AEC-Q100, choose a qualified alternative. Halogen-free status not specified in the provided data.
