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STMicroelectronics STCS1PUR
- Part No.:
- STCS1PUR
- Manufacturer:
- STMicroelectronics
- Category:
- LED Drivers
- Package:
- 8-VFDFN Exposed Pad
- Datasheet:
-
STCS1PUR.pdf
- Description:
- IC LED DRVR LINEAR PWM 1.5A 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,884
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Product details
Overview
STCS1PUR from STMicroelectronics is a BiCMOS constant current LED driver IC designed for low-voltage lighting systems operating from 4.5 V to 40 V input. It delivers up to 1.5 A output current with ±10% regulation accuracy, <0.5 V dropout voltage at 100 mA, and integrated PWM dimming and LED disconnection diagnostics. It replaces discrete current-source solutions in 5 V/12 V/24 V appliance and indicator lighting.
For engineers reviewing the STCS1PUR datasheet, STCS1PUR pinout, STCS1PUR application, or STCS1PUR equivalent, this page provides verified technical context, validated pin functions, real-world thermal and dimming performance data, and confirmed alternative drivers for LED current control in constrained-space, thermally sensitive designs.
Technical Context
The STCS1PUR implements a high-side N-MOSFET current regulator with internal 100 mV feedback reference and precision current-sense loop. Its architecture integrates a 45 V-rated preregulator stage, thermal shutdown (155 °C), and open-drain DISC flag triggered by VDRAIN < 75 mV - enabling real-time LED string integrity monitoring without external comparators.
It supports fast PWM dimming (up to 50 kHz) with ≤4 µs current rise/fall times and fixed 3 µs delay on PWM rising edge. Shutdown mode draws <1 µA, and EN/PWM logic thresholds are specified at VIL = 0.4 V and VIH = 1.2 V - ensuring compatibility with 3.3 V and 5 V microcontrollers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5 V to 40 V DC - supports wide-input industrial and automotive auxiliary rails without external LDO pre-regulation. |
| Max Output Current | 1.5 A - set via external FB resistor; enables driving high-brightness LED strings with single-device simplicity. |
| Feedback Reference | 100 mV ±10 mV - allows use of low-value, low-power sense resistors (e.g., 0.2 Ω for 500 mA) minimizing I²R loss. |
| Dropout Voltage | 0.16 V @ 100 mA / 0.9 V @ 1.5 A - ensures stable regulation even under high-current, low-VIN conditions (e.g., 5 V input with 3× white LEDs). |
| PWM Dimming Frequency | DC to 50 kHz - supports flicker-free dimming and synchronized multi-channel LED control with sub-µs timing alignment. |
| Diagnostic Flag | Open-drain DISC pin asserts low when VDRAIN < 75 mV - directly signals LED open-circuit fault to host MCU without polling or ADC. |
| Thermal Protection | 155 °C shutdown with 25 °C hysteresis - prevents latch-up during transient overloads and enables safe thermal recovery in enclosed fixtures. |
Pinout & Package
STCS1PUR is housed in a thermally enhanced DFN8 (3 × 3 mm) package with exposed die-pad for PCB heat sinking. The 8-pin layout supports compact 2-layer board placement and meets ECOPACK® environmental compliance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 VCC | Positive supply input | Accepts 4.5–40 V; powers internal bias and gate driver; requires 0.1 µF bypass capacitor to GND. |
| 2 PWM | Digital dimming control input | Active-high TTL/CMOS-compatible signal; controls main switch on/off; rise/fall delay ≤3 µs. |
| 3 EN | Enable/shutdown control | Logic-low disables all circuitry, reducing quiescent current to <1 µA; no external pull-up required. |
| 4 DRAIN | N-MOSFET drain terminal | High-side current path output; connects to LED anode; rated for 45 V max and 1.5 A continuous. |
| 5 FB | Current-sense feedback input | Regulates current so average voltage = 100 mV; connects to cathode side of external sense resistor. |
| 6 GND | Power and signal reference ground | Must be low-impedance connection; shares return path with sense resistor and bypass capacitors. |
| 7 N.C. | No connect | Mandatory floating pin; must not be tied to any net or plane to ensure proper operation. |
| 8 DISC | Open-drain fault flag output | Pulls low when LED string disconnects (VDRAIN < 75 mV); requires external pull-up for MCU interrupt detection. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 45 V N-MOSFET | Eliminates need for external high-voltage switch and gate driver, reducing BOM count and layout area. |
| 100 mV Precision Feedback | Enables accurate current setting with standard 1% metal-film resistors; reduces thermal drift vs. higher-reference alternatives. |
| LED Disconnection Detection | Hardware-level fault reporting via DISC pin avoids software polling delays and enables fail-safe system response. |
| Ultra-Low Shutdown Current | <1 µA shutdown draw extends battery life in portable LED applications and simplifies power sequencing. |
| Thermally Optimized DFN8 | 37.6 °C/W junction-to-ambient (4-layer PCB) enables 556 mW dissipation at 50 °C ambient - sufficient for 500 mA @ 12 V. |
Applications
| Smart Appliance Indicator Lighting | Industrial Panel Status LEDs |
|---|---|
|
Use Scenario: Constant-current drive for front-panel status LEDs in washing machines, ovens, and HVAC controllers powered from 12 V or 24 V internal rails. IC Role / Device Role / Timing Role: High-side LED current regulator with EN-controlled on/off sequencing and DISC-based open-wire fault detection. Use Value: Replaces 3–4 discrete components (MOSFET, op-amp, comparator, resistor network) while improving current accuracy to ±10% and enabling automated field failure logging. |
Use Scenario: Driving multi-color status indicators on PLC I/O modules and HMI panels where input voltage varies between 5 V and 24 V due to shared power distribution. IC Role / Device Role / Timing Role: Input-voltage-agnostic current source with PWM dimming for brightness control and DISC flag for predictive maintenance alerts. Use Value: Maintains consistent LED brightness across rail variations and reports LED failures before complete system downtime occurs. |
| Low-Voltage Architectural Accent Lighting | USB-Powered Portable LED Lamps |
|
Use Scenario: Powering 3–5 white LEDs (VF ≈ 3.6 V each) from 12 V or 24 V DC supplies in retail display and museum lighting fixtures. IC Role / Device Role / Timing Role: Constant-current source with <0.5 V overhead enabling full LED string utilization even at minimum input voltage. Use Value: Maximizes usable input range and eliminates need for boost converters or inefficient linear regulators in space-constrained luminaires. |
Use Scenario: Compact LED lamp powered from USB 5 V (±5%) with adjustable brightness and thermal-safe operation in plastic enclosures. IC Role / Device Role / Timing Role: Low-dropout current regulator with thermal shutdown and 3.3 V–compatible PWM/EN inputs for direct MCU interfacing. Use Value: Enables reliable 500 mA LED drive from marginal 5 V sources while preventing overheating in sealed housing via 155 °C protection. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar constant-current LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AL8862Q-7 | Switching buck LED driver; requires external inductor; 30 V max input; 1.2 A max output; no integrated DISC diagnostic. | Better efficiency (>90%) in high-VIN/high-IO cases but larger solution size and no open-load detection. | Select when >85% efficiency is mandatory and PCB area permits inductor placement; avoid when fault reporting is required. |
| LM3407MMX/NOPB | Analog linear LED driver; 2.7–24 V input; 1.5 A max; 200 mV reference; no PWM input - uses analog dimming only. | Simpler layout and lower EMI, but lacks digital dimming control and failsafe diagnostics. | Select for cost-sensitive, low-frequency dimming applications where DISC flag and precise PWM timing are unnecessary. |
Compared with AL8862Q-7 and LM3407MMX/NOPB, STCS1PUR uniquely combines linear simplicity, integrated diagnostics, and 40 V input tolerance in a 3×3 mm DFN - making it optimal for space-constrained, safety-aware 5–24 V LED systems requiring deterministic fault response.
Availability
STCS1PUR is available at Aetrix Electronics and suitable for smart appliance indicator lighting, industrial panel status LEDs, and low-voltage architectural accent lighting requiring stable component supply and long-term production continuity.
Supply support for STCS1PUR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in power management, analog, MEMS, and microcontroller technologies for industrial, automotive, and consumer markets.
The STCS1 series belongs to ST's LED driver product line, engineered specifically to replace discrete current-source circuits in low-voltage, high-reliability lighting applications - prioritizing integration, thermal robustness, and built-in diagnostics.
FAQ
What is the minimum input voltage required for STCS1PUR to regulate 1.5 A LED current?
The STCS1PUR requires sufficient headroom between input voltage and LED forward voltage plus dropout. At 1.5 A, typical dropout is 0.58 V (max 0.9 V). For a 3× white LED string (VF ≈ 3.6 V each), minimum VIN = 3×3.6 V + 0.9 V = 11.7 V. Below this, regulation fails and current drops nonlinearly.
Can STCS1PUR drive multiple parallel LED strings reliably?
No - STCS1PUR is a single-string, high-side constant-current source. Driving parallel strings causes current imbalance due to VF mismatches, risking thermal runaway. It is designed exclusively for one LED string per device; multi-string systems require one STCS1PUR per string or a matrix-switched architecture.
How does the DISC pin behave during PWM dimming?
The DISC pin remains functional during PWM operation: if VDRAIN falls below 75 mV at any point (e.g., due to LED disconnection), DISC pulls low immediately - independent of PWM state. This allows fault detection even while dimming, enabling real-time system diagnostics without interrupting light control.
Is an external reverse-polarity protection diode required for STCS1PUR?
Yes - the datasheet explicitly states STCS1PUR must be protected from reverse supply connection. A BAT46 or similar Schottky diode in series with VCC is recommended. Without it, reverse voltage applied to VCC can damage the internal 45 V preregulator and bandgap circuitry, as the device lacks built-in reverse-voltage blocking.
STCS1PUR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-VFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Linear
- Topology:
- -
- Internal Switch(s):
- Yes
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 4.5V
- Voltage - Supply (Max):
- 40V
- Voltage - Output:
- -
- Current - Output / Channel:
- 1.5A
- Frequency:
- -
- Dimming:
- PWM
- Applications:
- -
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-DFN (3x3)
STCS1PUR FAQ
1.How can I place an order for STCS1PUR through Aetrix?
Please submit a Request for Quotation (RFQ) for STCS1PUR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for STCS1PUR reliable?
The price and inventory of STCS1PUR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STCS1PUR is usually 5 days.
3.What payment methods are accepted for STCS1PUR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STCS1PUR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STCS1PUR?
STCS1PUR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STCS1PUR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for STCS1PUR?
For technical support, including STCS1PUR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STCS1PUR requirements.
6.How does Aetrix verify that STCS1PUR is sourced from the original manufacturer or authorized distributors?
All STCS1PUR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that STCS1PUR meets industry standards.
7.What is the process for return or replacement of STCS1PUR?
All STCS1PUR units undergo pre-shipment inspection (PSI). If there is an issue with STCS1PUR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The STCS1PUR part is unused and in its original packaging.
Return procedure for STCS1PUR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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