Description
The STEVAL-ISA153V1 product evaluation board
implements a 12 V/1.25 A, 15 W (20 W peak)
isolated flyback wide-range mains developed for
general-purpose applications.
The core of the application is the VIPER38LE, the
latest offline converter from the VIPerPlus family.
The device is a high-voltage converter that
smartly integrates an 800 V rugged power
MOSFET with PWM current-mode control. The
device features an adjustable extra power timer
(EPT) that enables the IC to sustain overload
conditions for a few seconds.
The main characteristics of the evaluation board
are its small size and minimal BOM, high
efficiency and low standby consumption.
Extremely low consumption under no-load
conditions is ensured thanks to burst mode
operation which reduces the average switching
frequency and minimizes all frequency-related
losses.
The VIPER38LE operates at a fixed 60 kHz
frequency. Frequency jittering is implemented,
which helps the application meet electromagnetic
disturbance standards.
The IC includes high-level protection features
such as dual-level OCP, output overvoltage,
short-circuit, and thermal shutdown with
hysteresis. After removal of a fault condition, the
IC is automatically restarted.

Features
• Universal input mains range: 90 – 265 VAC
frequency: 50 - 60 Hz
• Output voltage/current: 12 V/1.25 A (1.65 A
peak)
• Very compact size
• Standby mains consumption: lower than 30
mW at 230 VAC
• Minimum active mode efficiency: 81.55%
• Minimum active mode at 10% load efficiency:
71.55%
• EMI: in accordance with EN55022-Class-B
• RoHS compliant