STMicroelectronics ST1CC40DR

Overview

ST1CC40 from STMicroelectronics is a monolithic 3 A step-down constant-current DC-DC converter with synchronous rectification, designed for high-brightness LED driving. It operates from 3.0 V to 18 V input, delivers ±7% output current accuracy, features 850 kHz fixed switching frequency, and uses a 100 mV typical current-sense voltage drop to set LED current via external resistor. It is deployed in emergency lighting systems requiring stable, thermally robust current regulation.

For engineers reviewing the ST1CC40 datasheet, ST1CC40 pinout, ST1CC40 application, or ST1CC40 equivalent, key selection criteria include its 95 mΩ HS / 69 mΩ LS R_DS(on), embedded compensation network, thermal shutdown at 150 °C, and dual-package availability (VFQFPN8 and SO8) for layout flexibility in space-constrained LED driver designs.

Technical Context

The ST1CC40 implements peak current mode control with a fixed 850 kHz oscillator and integrated transconductance error amplifier (250 µS, 96 dB low-frequency gain). Its feedback loop compares a 100 mV internal reference against voltage across an external sense resistor to regulate LED current precisely.

It integrates synchronous high-side and low-side MOSFETs, supports ceramic output capacitors, and embeds soft-start (1 ms), hiccup-mode overcurrent protection, and inhibit logic that reduces quiescent current to 6 µA. Thermal shutdown activates at 150 °C with 15 °C hysteresis, and UVLO ensures reliable startup above 2.6 V.

Key Specifications

Pinout & Package

The ST1CC40 is available in two thermally optimized packages: VFQFPN8 (4 mm × 4 mm × 1.08 mm) and standard SO8-BW. Both support high-power dissipation with R_thJA of 40 °C/W (VFQFPN8) and 65 °C/W (SO8).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar constant-current LED driver applications.

Compared with LM3409HVMM/NOPB and MPQ4425AGU-AEC1-P, the ST1CC40 offers fully integrated synchronous switching, embedded compensation, and lowest system-level component count - ideal for rapid deployment in non-automotive LED current regulation where thermal robustness and standby efficiency are prioritized.

Availability

ST1CC40 is available at Aetrix Electronics and suitable for battery charger systems, emergency lighting installations, and high-brightness LED driving applications requiring stable component supply, long-term lifecycle assurance, and dual-package flexibility (VFQFPN8 and SO8).

Supply support for ST1CC40 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, delivering intelligent power, analog, MEMS, and microcontroller solutions for industrial, automotive, and consumer markets.

The ST1CC40 belongs to ST's dedicated LED driver product line, engineered specifically for high-efficiency, thermally resilient constant-current regulation in commercial and industrial solid-state lighting applications - not general-purpose DC-DC conversion.

FAQ

What is the minimum input voltage required for ST1CC40 to regulate 3 A LED current?

The ST1CC40 requires a minimum input voltage of 3.0 V to operate, but practical regulation at full 3 A load demands sufficient headroom above the LED string forward voltage plus dropout across the sense resistor and internal switches. For example, driving a 9 V LED string requires ≥10.5 V input to maintain regulation margin across temperature and component tolerances.

Can ST1CC40 drive multiple parallel LED strings reliably?

Yes - ST1CC40 can drive multiple parallel LED strings when each string includes a matched current-sense resistor, ensuring equal current sharing. However, for best accuracy and thermal balance, ST recommends using one ST1CC40 per string or implementing external current-mirror circuitry to avoid forward-voltage mismatch errors.

How does the inhibit (INH) pin affect thermal performance during standby?

When INH is pulled low, the ST1CC40 disables its power stage and most internal circuitry, reducing total supply current to 6 µA typical. This eliminates switching and conduction losses, allowing junction temperature to decay rapidly - critical for maintaining reliability in thermally constrained emergency lighting housings during extended standby periods.

Is external compensation required for stable operation with standard LED loads?

No - the ST1CC40 embeds a pre-optimized compensation network (RC = 70 kΩ, CC = 195 pF) validated for stability with typical LED loads and ceramic output capacitors. External compensation is unnecessary unless using ultra-low-ESR capacitors (<5 mΩ) or highly reactive LED models outside the specified 3–18 V input and 0.5–3 A current range.