STMicroelectronics TSM1013AIDT

Overview

TSM1013AIDT from STMicroelectronics is a dual-op-amp-based constant voltage (CV) and constant current (CC) controller IC for secondary-side feedback in flyback SMPS, featuring 2.5 V ±0.5% internal reference, 4.5–28 V supply range, and two transconductance amplifier outputs with 3.5 mA/mV gain. It enables precise regulation in AC/DC adapters and battery chargers.

For engineers reviewing the TSM1013AIDT datasheet, TSM1013AIDT pinout, TSM1013AIDT application, or TSM1013AIDT equivalent, key selection criteria include reference precision (0.5%), dual op-amp input offset (≤2 mV), sink-output capability (50 mA short-circuit current), thermal resistance (175 °C/W), and SO-8 package compatibility with optocoupler-based isolated feedback loops.

Technical Context

The TSM1013AIDT integrates two independent transconductance operational amplifiers sharing a common 2.5 V reference: one configured as a CV controller (via Cv−/Cv Out) and the other as a CC limiter (via Cc−/Cc+/Cc Out). Both amplifiers support full external compensation via accessible inputs and outputs.

Its architecture enables ORing of CV and CC control paths through shared sinking outputs, ensuring immediate optocoupler activation when either loop exceeds threshold - critical for safe foldback behavior during overvoltage or overcurrent events in isolated power supplies.

Key Specifications

Pinout & Package

Package: SO-8 (Small Outline, 150 mil width), surface-mount, RoHS-compliant, with 1.27 mm pitch and 175 °C/W junction-to-ambient thermal resistance.

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, TSM1013AIDT reduces board area by >40% and improves CV/CC cross-regulation; versus UCC3803-1, it delivers true integrated dual-loop control without external comparators or logic gates - essential for compact, certified adapter designs.

Availability

TSM1013AIDT is available at Aetrix Electronics and suitable for USB-C PD adapters, lithium-ion battery chargers, and industrial AC/DC power supplies requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TSM1013AIDT 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 ICs, analog chips, and MEMS sensors for automotive, industrial, and consumer markets.

The TSM1013AIDT belongs to ST's dedicated power management analog controller family, engineered specifically for cost-sensitive, isolated flyback converters needing accurate secondary-side CV/CC regulation without digital complexity.

FAQ

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

The TSM1013AIDT features an internal zener clamp rated at 28 V. When Vcc exceeds this value - for example, due to transformer leakage spikes or unregulated auxiliary winding voltages - the clamp activates to protect internal circuitry. Absolute maximum rating is 28 V; sustained operation above this risks permanent damage. External limiting resistors must be sized using Rlimit = (Vcc − 28 V)/Ivz per datasheet Figure 4.

Can TSM1013AIDT drive optocouplers directly without external transistors?

Yes. Each output (Cv Out and Cc Out) can sink up to 50 mA continuously, sufficient to drive standard linear optocouplers like PC817 (IF = 5–20 mA) or SFH615A (IF = 10 mA) directly. No external transistor buffer is needed, reducing component count and improving loop response time in adapter applications.

How does the 0.5% reference accuracy translate to overall output voltage tolerance?

With 0.5% Vref accuracy and typical resistor divider tolerances (1% R1/R2), the TSM1013AIDT achieves ≤1.2% total output voltage error at room temperature. Over 0–105°C, ∆Vref adds ≤30 mV drift, resulting in <1.5% worst-case tolerance for a 5 V output - meeting Class II adapter specifications per IEC 61347.

Is external compensation mandatory for stable loop operation?

Yes. Both op-amps require external RC compensation networks connected between their outputs and inverting inputs. The datasheet recommends 22 kΩ + 2.2 nF for each loop (Figure 2). Omitting compensation causes instability, oscillation, or poor transient response - especially under load step changes or wide temperature swings.