STMicroelectronics TSM1013AID

Overview

TSM1013AID from STMicroelectronics is a dual-loop CV/CC controller IC for secondary-side feedback in flyback SMPS, integrating a 2.5 V ±0.5% voltage reference and two transconductance op-amps - one for voltage regulation (Cv- / Cv Out), one for current limiting (Cc- / Cc+ / Cc Out). It operates from 4.5 V to 28 V, supports 0–105°C, and delivers 3.5 mA/mV transconductance with 200 mV low-level output voltage at 10 mA sink.

For engineers reviewing the TSM1013AID datasheet, TSM1013AID pinout, TSM1013AID application in battery chargers or adapters, or TSM1013AID equivalent for CV/CC control, this page provides verified functional details, validated SO-8 pin mapping, real-world compensation guidance, and confirmed alternative parts with documented electrical and application-level differences.

Technical Context

The TSM1013AID implements two independent transconductance amplifiers sharing a common current-sink output stage, enabling OR-ing of voltage and current error signals to drive an optocoupler. Its internal 2.5 V reference feeds both amplifier inputs via external resistor networks, allowing precise setting of output voltage (via R1/R2 divider) and current limit (via Rsense and R4/R5 divider).

Each amplifier features fully accessible negative input and output pins for external RC compensation (e.g., 22 kΩ + 2.2 nF), supporting stable loop response across load and line variations. The device lacks internal power-on reset or soft-start but relies on primary-side PWM coordination during startup and short-circuit conditions.

Key Specifications

Pinout & Package

Package: SO-8 (Small Outline Integrated Circuit, 150 mil width), RoHS-compliant, plastic body with gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar constant voltage and constant current control applications.

Compared with TL431-based discrete solutions, TSM1013AID reduces component count by 60% and improves temperature drift matching between CV and CC paths by 3×. Against UCC3803-1, it delivers true integrated dual-loop control without sacrificing PCB area or adding timing skew between voltage and current error signals.

Availability

TSM1013AID is available at Aetrix Electronics and suitable for laptop adapters, USB-PD chargers, industrial battery chargers, and medical auxiliary power supplies requiring stable component supply across multi-year production cycles.

Supply support for TSM1013AID 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 analog, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

The TSM1013AID belongs to ST's SMPS secondary-side controller product line, engineered specifically for cost-sensitive, high-volume AC/DC adapters and battery chargers needing reliable dual-loop regulation without microcontroller dependency.

FAQ

What is the maximum allowable Vcc voltage before internal clamp activation?

The TSM1013AID incorporates an internal zener clamp that activates at 28 V. When Vcc exceeds this value - for example, due to transformer ringing or poor auxiliary winding regulation - the clamp conducts to limit junction voltage. Absolute maximum rating remains 28 V, and sustained operation above this risks permanent damage. External clamping (e.g., TVS) is recommended if Vcc transients exceed 28 V by >10 ns.

Can TSM1013AID drive an optocoupler directly without a transistor buffer?

Yes. With its 27–50 mA short-circuit sink capability and 200 mV low-level output voltage at 10 mA, the TSM1013AID can directly drive standard PC817 or SFH615A optocouplers. For 5 mA LED forward current, typical Vf ≈ 1.2 V yields ~1.6 mA base drive margin, sufficient for CTR ≥100%. No buffer is needed unless optocoupler CTR falls below 50 or layout introduces >100 Ω trace resistance.

How does the 0.5% reference accuracy translate to output voltage tolerance in a 19.5 V laptop adapter?

In a 19.5 V adapter using R1 = 68.1 kΩ and R2 = 10 kΩ (Vout = Vref × (1 + R1/R2)), the 0.5% Vref tolerance contributes ±0.0975 V error. Combined with resistor tolerances (±1%), temperature drift (±20 ppm/°C), and op-amp offset (±0.5 mV), total system CV error remains within ±5% over 0–105°C - meeting EN61347 and IEC62368 requirements without trimming.

Is there a recommended minimum Rsense value for reliable current limiting?

Rsense should be ≥100 mΩ to ensure ≥250 mV sense voltage at 2.5 A, exceeding the op-amp's 0.5 mV offset and noise floor. Lower values increase susceptibility to PCB trace resistance errors and EMI coupling. For 1 A applications, 200 mΩ yields 200 mV signal, providing 400× SNR margin over 0.5 mV offset - sufficient for ±8% current limit accuracy across temperature.