STMicroelectronics VIPER17LD

Overview

VIPER17LD from STMicroelectronics is a high-voltage integrated flyback controller and 800 V avalanche-rugged power MOSFET in a single SO16 narrow package, operating at 60 kHz with frequency jittering for EMI reduction, <30 mW standby power at 265 VAC, adjustable current limit via CONT pin, and integrated OVP, brown-out, thermal shutdown, and safe auto-restart-designed for compact AC/DC adapters and auxiliary supplies in consumer electronics.

For engineers reviewing the VIPER17LD datasheet, VIPER17LD pinout, VIPER17LD application, or VIPER17LD equivalent, key selection considerations include its 800 V drain-source breakdown, SO16 narrow thermal performance (R_thJA = 80 °C/W on FR4), burst-mode operation at light load, and dual-level overcurrent protection architecture requiring precise RLIM resistor selection for current limit tuning.

Technical Context

The VIPER17LD integrates a current-mode PWM controller with an internal 800 V N-channel SenseFET, enabling direct primary-side regulation without optocoupler feedback in low-to-mid power flyback topologies. Its oscillator delivers fixed 60 kHz switching with ±4 kHz jitter at 250 Hz to spread spectral energy and reduce EMI filter cost.

Brown-out protection triggers at 0.45 V on BR pin (hysteresis 50 mV), while overvoltage protection monitors output via CONT pin during MOSFET off-time using digitally strobed sampling (2.2 µs delay, 4-consecutive-cycle detection) to reject noise and ensure reliable latch-free shutdown.

Key Specifications

Pinout & Package

Package: SO16 narrow (10.3 × 10.3 mm, 1.75 mm height), thermally enhanced with exposed pad connected to DRAIN pins 13–16 for PCB copper heat sinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICE3B0565J and VIPER22ADIP, VIPER17LD offers superior integration (HV startup, brown-out, digital OVP), tighter thermal management in SO16, and lower no-load consumption-making it optimal for space-constrained, regulatory-compliant AC/DC adapters where BOM count and EMC time-to-market are critical.

Availability

VIPER17LD is available at Aetrix Electronics and suitable for smartphone charging adapters, PDA power supplies, LCD TV auxiliary rails, and no-electrolytic-capacitor LED drivers requiring stable component supply across industrial and consumer production programs.

Supply support for VIPER17LD 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, sensors, and analog devices for automotive, industrial, and consumer markets.

VIPER17LD belongs to the VIPerPlus family of high-voltage offline controllers, engineered specifically for cost-sensitive, low-to-mid power AC/DC conversion where integration, safety compliance, and energy efficiency are paramount.

FAQ

What is the purpose of the CONT pin on VIPER17LD?

The CONT pin serves two distinct functions: (1) adjusting the cycle-by-cycle current limit threshold via an external resistor (RLIM) to tailor peak primary current for specific transformer designs, and (2) monitoring the auxiliary winding voltage during MOSFET off-time to enable accurate, noise-immune overvoltage protection. It is not a general-purpose analog input and must be configured per Figure 27 in the datasheet.

How does VIPER17LD achieve <30 mW standby power?

VIPER17LD achieves ultra-low standby power through burst-mode operation-where the controller stops switching entirely when feedback voltage falls below 0.45 V, reducing quiescent current to 400 µA during fault or no-load conditions-and by integrating a high-voltage startup generator that draws current only during initial charge of the VDD capacitor, eliminating continuous resistive losses.

Can VIPER17LD replace VIPER22A in an existing design?

VIPER17LD can replace VIPER22A only with board-level modifications: the SO16 narrow footprint differs from VIPER22A's DIP-7, and CONT pin functionality differs (VIPER22A uses CONT solely for current limit). Additionally, VIPER17LD's 800 V BVDSS allows higher input surge tolerance, but its 20 Ω RDS(on) requires verification of thermal margin in the original layout.

What is the minimum recommended copper area under DRAIN pins for thermal performance?

STMicroelectronics recommends a minimum 100 mm² (0.155 in²) copper pour connected directly to pins 13–16 (DRAIN) on the PCB's top layer, using multiple thermal vias to inner ground planes. This configuration achieves R_thJA = 80 °C/W on standard FR4, enabling 9 W continuous operation at 50 °C ambient without forced airflow.