STMicroelectronics E-SG3525AN

Overview

E-SG3525AN from STMicroelectronics is a dual-output PWM controller IC designed for regulating switching power supplies, featuring an internal 5.1 V ±1% reference, oscillator frequency range of 100 Hz to 400 kHz, adjustable deadtime control via external resistor, and pulse-by-pulse shutdown capability. It operates from 8–35 V supply, includes undervoltage lockout with 500 mV hysteresis, and drives external MOSFETs or bipolar transistors in push-pull or single-ended topologies.

For engineers reviewing the E-SG3525AN datasheet, E-SG3525AN pinout, E-SG3525AN application, or E-SG3525AN equivalent, key selection considerations include its NOR-logic output stage (LOW = OFF), soft-start timing capacitor interface, sync input for multi-controller coordination, and latch-based PWM termination preventing multiple pulses per cycle.

Technical Context

The E-SG3525AN integrates a precision error amplifier with rail-to-rail common-mode input range including the 5.1 V reference, eliminating external bias resistors. Its oscillator uses external RT/CT/RD components to set frequency and deadtime, with sync input enabling master-slave configuration across multiple units.

Shutdown is implemented via Pin 10, which both sets the PWM latch for immediate output disable and sinks 150 µA to discharge the external soft-start capacitor-enabling either pulse-by-pulse current limiting (short pulse) or full soft-start recycle (long pulse). Undervoltage lockout holds outputs off and discharges soft-start capacitance below ~6.5 V with ~500 mV hysteresis.

Key Specifications

Pinout & Package

Package: 16-pin narrow-body plastic DIP (DIP16), 7.1 mm body width, 20 mm length, 0.1 inch lead pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with UC3525AN and TL5001CP, E-SG3525AN offers superior reference accuracy, integrated soft-start current source, and dedicated deadtime control-making it optimal for high-reliability industrial and telecom power supplies requiring precise timing coordination and robust fault handling.

Availability

E-SG3525AN is available at Aetrix Electronics and suitable for AC-DC adapters, industrial DC-DC converters, and telecom intermediate bus systems requiring stable component supply, long-lifecycle support, and consistent parametric performance across temperature and voltage ranges.

Supply support for E-SG3525AN 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, analog, microcontrollers, and automotive-grade ICs.

The SG3525A series was developed specifically for high-efficiency, high-reliability switching power supply control-targeting industrial, telecom, and lighting applications demanding precise regulation, thermal resilience, and robust fault protection.

FAQ

What is the maximum recommended oscillator frequency for E-SG3525AN?

The datasheet specifies a maximum oscillator frequency of 400 kHz under recommended operating conditions (RT = 2 kΩ, CT = 470 pF). This limit ensures stable operation of internal timing circuits and reliable PWM latch reset. Exceeding this frequency may cause timing skew, reduced deadtime margin, or inconsistent pulse termination-particularly at temperature extremes or low supply voltages.

How does the E-SG3525AN implement undervoltage lockout?

E-SG3525AN monitors the main supply (Vi) and disables all outputs while discharging the soft-start capacitor when Vi drops below approximately 6.5 V. The lockout includes ~500 mV hysteresis-meaning the device re-enables only when Vi rises above ~7.0 V-preventing oscillatory behavior during brownout conditions and ensuring clean startup after recovery.

Can E-SG3525AN drive MOSFETs directly without gate drivers?

Yes-each output can source or sink >200 mA, sufficient to charge/discharge typical gate capacitances of medium-power MOSFETs (e.g., ≤5 nF) within nanoseconds. However, for high-side N-channel MOSFETs in bridge configurations, external level-shifting or dedicated high-side drivers remain necessary due to the IC's ground-referenced output architecture.

What is the function of the VC pin, and how should it be connected?

The VC pin supplies the collector voltage for the totem-pole output drivers, allowing them to operate at a higher voltage (up to 35 V) than the main logic supply (Vi). It must be connected to a clean, well-decoupled voltage rail-often tied to Vi or a boosted auxiliary supply-to maximize drive strength and switching speed, especially when driving high-threshold MOSFETs or under heavy capacitive loads.