TS2937CP33 - 500mA 3.3V Ultra-LDO Fixed Regulator TO-252 | TSC
MPN: TS2937CP33 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.78 | $0.78 |
| 10 | $0.66 | $6.60 |
| 100 | $0.52 | $52.00 |
| 500 | $0.43 | $215.00 |
| 1,000 | $0.37 | $370.00 |
| 2,500 | $0.32 | $800.00 |
TS2937CP33 Overview
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.
Drop-in alternatives for TS2937CP33 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with TS2937CP33 (same form factor and footprint) — differing in Maximum Output Current, Package, Short-Circuit Protection.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
TS2937CP50
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
TS2937CP33 ROG
✅ Drop-In📋 Reference alternative (not in catalog)
TS2937CP12
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LD1117S33CTR
✅ Drop-In📋 Reference alternative (not in catalog)
LM1117MP-3.3
✅ Drop-In📋 Reference alternative (not in catalog)
MIC29150-3.3WT
✅ Drop-In📋 Reference alternative (not in catalog)
TS2937CP33 Maximum Ratings & Electrical Characteristics
| Regulator Type | Fixed Positive Linear (LDO) |
| Output Voltage | 3.3 V (fixed) |
| Output Voltage Tolerance | ±2% |
| Maximum Output Current | 500 mA |
| Dropout Voltage | 170 mV typical at 500 mA |
| Operating Temperature Range | -40 C to +125 C |
| Package | TO-252 (DPAK) |
| Mounting Type | Surface Mount |
| Number of Outputs | 1 |
| Thermal Shutdown | Yes (internal) |
| Short-Circuit Protection | Yes (internal current limit) |
| RoHS Status | Compliant |
TS2937CP33 Pin Configuration
| Pin 1 | VIN — Unregulated input voltage |
| Pin 2 | GND — Ground reference |
| Pin 3 | VOUT — Regulated 3.3 V output |
| Pin TAB | TAB — Exposed thermal pad (electrically connected to GND on standard variant) |
Typical Applications
TS2937CP33 is suitable for 6 applications: 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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
Recommended Products Summary
Engineering reference data for TS2937CP33 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | 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 |
Key Differentiators
- Ultra-low dropout for a TO-252 fixed LDO (vs LD1117S33CTR)
- Same-brand family variant at 3.3 V with tape-and-reel (vs TS2937CP33 ROG)
- Higher current capability in same footprint (vs MIC29150-3.3WT)
Design Notes
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.
Compliance Information
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.
