STMicroelectronics VIPER53ESP-E

Overview

VIPER53ESP-E from STMicroelectronics is an integrated offline primary switch combining a current-mode PWM controller and a 620 V MDMesh™ Power MOSFET in a PowerSO-10 package. It delivers up to 65 W in single European AC input (195–265 VAC) and 40 W in universal input (85–265 VAC), features adjustable peak current limiting (2 A typ), 100 kHz oscillator frequency (±5%), and built-in protections including overtemperature (160 °C), overload, short-circuit, overvoltage (18 V on VDD), and undervoltage lockout (11.5 V startup / 8.4 V shutdown).

For engineers reviewing the VIPER53ESP-E datasheet, VIPER53ESP-E pinout, VIPER53ESP-E application, or VIPER53ESP-E equivalent, key selection considerations include its integrated high-voltage start-up current source (−12 mA at VDD = 0–5 V), COMP pin dynamic range (0.5–4.5 V), burst-mode standby compliance (<0.5 W input), and thermal resistance (2 °C/W junction-to-case on FR4 with 50 mm² copper).

Technical Context

The VIPER53ESP-E implements a fixed-frequency current-mode control topology with cycle-by-cycle peak current sensing via internal SenseFET and voltage conversion at the COMP pin (HCOMP = 2 V/A). Its inner loop regulates primary peak current using a blanking time that switches between 150 ns (VCOMP > 1 V) and 400 ns (VCOMP ≤ 1 V), enabling stable operation down to minimum on-times of 350 ns or 600 ns respectively.

Standby operation uses automatic burst mode triggered when COMP falls below 0.5 V, reducing switching frequency while maintaining output regulation; the transition includes hysteresis between normal and burst modes defined by VCOMPbl = 1 V and VCOMPoff = 0.5 V, with no external components required for soft-start or overload delay beyond the TOVL capacitor (100 nF typical).

Key Specifications

Pinout & Package

Package: PowerSO-10 (exposed drain pad, thermally enhanced, RoHS-compliant surface-mount package with 2 °C/W R_thJC on standard FR4 board).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar offline primary switch applications.

Compared with VIPER53EDIP-E, the VIPER53ESP-E offers 30% higher EU power rating and superior thermal management; versus ICE3B0565J, it eliminates start-up resistors, reduces component count, and guarantees sub-0.5 W standby-critical for modern energy regulations.

Availability

VIPER53ESP-E is available at Aetrix Electronics and suitable for industrial control PSUs, smart home AC-DC adapters, LED driver power supplies, and white goods auxiliary supplies requiring stable component supply, long lifecycle support, and RoHS-compliant packaging.

Supply support for VIPER53ESP-E 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, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The VIPer™ family targets highly integrated, low-component-count offline SMPS designs-specifically optimizing for universal-input, low-standby-power, and thermally constrained applications using embedded MOSFET technology.

FAQ

What is the minimum external capacitor required on the VDD pin for reliable start-up?

A minimum VDD capacitor of C_VDD > (I_DD1 × t_ss) / V_DDhyst is required, where I_DD1 = 9 mA, V_DDhyst = 3.1 V, and t_ss depends on transformer design and soft-start configuration. Typical values range from 4.7 µF to 22 µF ceramic or low-ESR electrolytic, sized to sustain VDD above 8.4 V until auxiliary winding takes over.

How does the TOVL pin implement overload delay, and what capacitor value is recommended?

The TOVL pin connects to an external capacitor that sets the time constant for overload detection: a 100 nF capacitor yields an 8 ms delay before shutdown when COMP exceeds 4.35 V. This delay prevents false triggering during transient overloads while ensuring robust protection during sustained faults like output short circuits.

Can VIPER53ESP-E operate without an optocoupler in the feedback path?

Yes-it supports primary-side regulation using auxiliary winding sensing, though ST's reference designs emphasize secondary-side optocoupler+TL431 feedback for tighter regulation. The COMP pin's 0.6 mA constant bias current simplifies optocoupler interfacing but does not preclude alternative feedback topologies with appropriate compensation.

What is the purpose of the dual blanking time (150 ns / 400 ns), and how is it selected?

The blanking time switches automatically: 150 ns when COMP > 1 V (normal operation), 400 ns when COMP ≤ 1 V (burst-mode entry). This prevents false current-sense triggering from transformer leakage spikes during light-load conditions while maintaining fast response under full-load operation-no external configuration is needed.