STMicroelectronics TSM007IDT

Overview

TSM007IDT from STMicroelectronics is a fixed-frequency current-mode PWM controller IC designed for offline and DC-DC SMPS applications. It integrates internal UVLO (7.9 V turn-on / 7.3 V turn-off), programmable soft start (10 µA source current), 2 kV ESD protection, and high-current totem-pole output (1 A peak) capable of directly driving power MOSFETs. Used in PC switch-mode power supplies.

For engineers reviewing the TSM007IDT datasheet, TSM007IDT pinout, TSM007IDT application, or TSM007IDT equivalent, key selection criteria include oscillator frequency stability (±0.5% over supply range), brown-out threshold accuracy (2.50 V ±0.08 V), current sense gain (3.00 V/V), UVLO hysteresis (1.6 V), and soft-start current temperature coefficient (7–13 µA over 0–70°C).

Technical Context

The TSM007IDT implements current-mode control via COMP input (voltage reference for CS comparator) and CS pin (0–1.0 V sensing range with 3.00 V/V gain). Its oscillator uses CT pin with external capacitor to set frequency (84–116 kHz typical at 1.5 nF), featuring dual charge/discharge currents (400 µA/600 µA) and 1.6 V amplitude swing.

Brown-out protection monitors BRNOUT pin with 2.50 V threshold and 50 µA source current; UVLO disables operation below 7.9 V with 1.6 V hysteresis. Soft start is implemented via SS pin (10 µA source, 4.2 V clamp) and synchronized to CT voltage minus diode drop, enabling controlled duty-cycle ramp-up.

Key Specifications

Pinout & Package

Package: SO-8 (Small Outline, 150 mil width), RoHS-compliant plastic package per mechanical drawing 0016023/C.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar primary-side PWM controller applications.

Compared with UC3844BD1R2G and TL494CN, the TSM007IDT delivers higher integration (on-chip UVLO, brown-out, soft start, and 1 A gate drive), reducing BOM count and layout complexity for single-MOSFET flyback designs - especially where fast, repeatable startup and line-fault resilience are critical.

Availability

TSM007IDT is available at Aetrix Electronics and suitable for desktop PC SMPS, LCD monitor power supplies, and industrial AC-DC adapters requiring stable component supply and long-term design continuity.

Supply support for TSM007IDT 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, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

The TSM007 belongs to ST's legacy primary-side PWM controller product line, engineered specifically for cost-sensitive, high-volume offline SMPS applications where integration, reliability, and ease of implementation are prioritized over programmability.

FAQ

What is the recommended CT capacitor value for 100 kHz operation?

The datasheet specifies 1.5 nF for 100 kHz operation, calculated using Ici = 400 µA, Icd = 600 µA, and ∆Vct = 1.6 V. Using this value ensures nominal frequency accuracy within ±2% over temperature and supply variations. Deviations beyond ±10% may shift frequency outside the 84–116 kHz guaranteed range.

Can the TSM007IDT be used without an external soft-start capacitor?

No - the SS pin must be connected to a capacitor to ground for proper startup. Without it, the soft-start comparator cannot ramp the duty cycle, causing uncontrolled full-duty initial pulse that may overstress the MOSFET or transformer. Minimum recommended Css is 100 nF for basic stabilization; 210 nF achieves ~50 ms ramp per design example.

How does the BRNOUT pin interface with the bulk capacitor voltage?

BRNOUT connects to a resistor divider (e.g., R1 = 1.185 MΩ, R2 = 15 kΩ) across the bulk capacitor. At 200 V input, the divider scales voltage to 2.50 V at BRNOUT. When bulk voltage drops below this, the IC enters standby: Vref disables, OUT goes low, and SS/CT discharge - ensuring graceful shutdown before under-voltage stress occurs.

Is the TSM007IDT still in active production?

No - STMicroelectronics has marked the TSM007 series as Obsolete Product(s). Aetrix Electronics maintains legacy inventory and offers lifecycle support including last-time-buy planning, cross-reference guidance, and obsolescence mitigation for existing designs still in production.