STMicroelectronics L6933H1.2TR

Overview

L6933H1.2TR from STMicroelectronics is a high-performance 2 A ultra-low dropout (ULDO) linear regulator in HSOP8 package, featuring adjustable output (1.2 V to 5 V), ±1 % regulation accuracy, 200 mΩ max r_DS(on), 200 µA quiescent current, and integrated Power Good output. It delivers stable local power for processor I/O and chipset supplies in mobile PC motherboards and handheld instruments.

For engineers reviewing the L6933H1.2TR datasheet, L6933H1.2TR pinout, L6933H1.2TR application, or L6933H1.2TR equivalent, key selection criteria include soft-start programmability via external capacitor, INH/SS dual-function pin behavior, thermal shutdown with 20 °C hysteresis, and MLCC-compatible stability without external compensation.

Technical Context

The L6933H1.2TR integrates an internal 50 mΩ N-channel MOSFET pass element and uses a precision bandgap reference with error amplifier to achieve 1 % output voltage accuracy across load, line, and temperature. Its soft-start function sources a fixed 5 µA current into an external capacitor at SS/INH pin, enabling controlled V_OUT ramp-up and eliminating overshoot during startup.

Protection architecture includes cycle-by-cycle current limiting (2.5 A typical), short-circuit foldback, and thermal shutdown triggered at 150 °C with 20 °C hysteresis. The open-drain PGOOD pin asserts low when V_OUT drops below 90 % of programmed value, with 10 % hysteresis and 0.4 V saturation voltage at 1 mA sink.

Key Specifications

Pinout & Package

HSOP8 package: 8-pin exposed-pad surface-mount package with GND-connected thermal pad, optimized for thermal dissipation in space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low dropout linear regulator applications.

Compared with TPS7A4700RGWR and ADM7172ACPZ-R7, the L6933H1.2TR uniquely combines 2 A current capability, adjustable output, dual-function SS/INH pin, and PGOOD in HSOP8 - making it optimal for space-constrained, multi-rail mobile systems requiring flexible sequencing and protection.

Availability

L6933H1.2TR is available at Aetrix Electronics and suitable for mobile PC motherboards, handheld instrumentation, PCMCIA card power management, and chipset voltage scaling requiring stable component supply and long-term lifecycle support.

Supply support for L6933H1.2TR 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 silicon solutions for automotive, industrial, and consumer markets with emphasis on energy efficiency and reliability.

The L6933H1.2TR belongs to ST's high-current ULDO regulator product line, engineered specifically for high-density computing platforms where low dropout, precise voltage control, and robust protection are essential for processor and memory subsystems.

FAQ

What is the minimum input voltage required for 1.2 V output at 2 A?

The L6933H1.2TR achieves ultra-low dropout with 200 mΩ max r_DS(on), so minimum input is V_OUT + I_OUT × r_DS(on) = 1.2 V + 2 A × 0.2 Ω = 1.6 V. However, datasheet specifies absolute minimum VIN as 2 V for guaranteed operation across temperature and process variation - use ≥2.2 V for margin in production designs.

Can the SS/INH pin be left floating?

No. The SS/INH pin must be either connected to an external soft-start capacitor (for startup control) or pulled to GND via a switch (for enable/disable). Floating this pin causes undefined behavior: the internal 5 µA current source may drive unpredictable voltage, risking erratic enable/disable or failed soft-start.

Is an external diode required for reverse-voltage protection?

No. The L6933H1.2TR contains internal reverse-battery protection circuitry that blocks current flow when VIN < VOUT, preventing damage during input reversal or back-driving. This eliminates need for external Schottky diodes in battery-powered applications.

How does the PGOOD output behave during thermal shutdown?

During thermal shutdown, the L6933H1.2TR disables the pass transistor and forces VOUT to drop. Once VOUT falls below 90 % of its regulated value, PGOOD transitions low within 10 µs and remains low until VOUT recovers above the threshold plus 10 % hysteresis - providing unambiguous fault signaling to system supervisors.