STMicroelectronics STCS05ADR

Overview

STCS05ADR from STMicroelectronics is a BiCMOS constant current LED driver IC designed for low-voltage LED lighting systems operating from 4.5 V to 40 V input. It delivers up to 0.5 A output current with ±10% regulation accuracy, <0.5 V dropout voltage at 0.5 A, and integrates PWM dimming control, shutdown enable, and open-drain LED disconnection diagnostic. It replaces discrete current-source solutions in 5 V/12 V/24 V appliance and indicator lighting.

For engineers reviewing the STCS05ADR datasheet, STCS05ADR pinout, STCS05ADR application, or STCS05ADR equivalent, key selection criteria include its 100 mV FB reference for precision current setting via external resistor, slope-controlled current rise/fall (via SLOPE pin capacitor), sub-1 µA shutdown current, and integrated thermal protection with 155 °C shutdown threshold.

Technical Context

The STCS05ADR implements a high-side N-MOSFET constant current source controlled by an internal error amplifier comparing FB voltage to a 100 mV reference. Its architecture includes a dedicated slope-control loop using an external capacitor on the SLOPE pin to linearly adjust current rise/fall time from ~800 µs to milliseconds-enabling EMI reduction and inrush mitigation.

Diagnostic functionality monitors DRAIN-to-GND voltage: when below 75 mV (indicating LED string open), the DISC pin pulls low (open-drain). The EN pin enables full shutdown (<1 µA ICC), while PWM directly gates the internal MOSFET with <3 µs delay and supports dimming up to 50 kHz.

Key Specifications

Pinout & Package

STCS05ADR is housed in an SO-8 package (ECOPACK® compliant, 1.27 mm pitch), with exposed pad for thermal enhancement. Pin 4 (DRAIN) connects to the LED anode side; Pin 5 (FB) senses current through external resistor to GND; Pin 8 (DISC) provides open-drain fault flag.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AL8862SP-13 and NSI50010YT1G, STCS05ADR uniquely balances linear simplicity with digital control (PWM/EN/DISC), making it optimal for mid-power (≤500 mA), low-EMI, diagnostic-aware LED systems on 5–24 V rails.

Availability

STCS05ADR is available at Aetrix Electronics and suitable for architectural lighting controls, appliance status indicators, and industrial panel meters requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for STCS05ADR 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, designing and manufacturing microcontrollers, power management ICs, analog chips, and MEMS sensors for industrial, automotive, and consumer markets.

The STCS05A product line targets replacement of discrete LED current sources in low-voltage, space-constrained applications - emphasizing integration, precision, and built-in diagnostics for reliable lighting subsystems.

FAQ

What is the minimum input voltage required for STCS05ADR to regulate 500 mA?

The STCS05ADR requires a minimum input voltage equal to the sum of LED forward voltage plus dropout voltage. At 500 mA, typical dropout is 0.58 V; thus, for a 3.2 V white LED, minimum V_IN = 3.78 V. The absolute minimum specified is 4.5 V to ensure guaranteed operation across process and temperature.

Can STCS05ADR drive multiple parallel LED strings?

No - STCS05ADR is a single-channel high-side current source intended for one LED string. Driving parallel strings would cause current imbalance due to V_F mismatch, risking thermal runaway. For multi-string applications, one STCS05ADR per string is required, with independent R_FB and DISC monitoring.

How does the SLOPE capacitor affect PWM dimming performance?

The SLOPE capacitor sets the current slew rate, directly impacting PWM edge fidelity. With 10 nF, rise/fall time is ~800 µs - acceptable for ≤1 kHz dimming. At 50 kHz, the current waveform becomes triangular due to limited slew rate, reducing effective dimming resolution. For high-frequency dimming, minimize or omit the capacitor.

What happens to the DISC pin during shutdown (EN = low)?

When EN = low, the entire internal circuitry is disabled, including the DISC comparator. The DISC pin enters high-impedance (floating) state and does not assert a fault signal. DISC only functions when EN = high and the device is actively regulating current.