STEVAL-ISA176V1 Datasheet, PDF (1/5 Pages) STMicroelectronics – ALTAIR05T-800 5 W wide range CV-CC optoless adapter evaluation board

STEVAL-ISA176V1
ALTAIR05T-800 5 W wide range CV-CC optoless adapter
evaluation board
Data brief
Features
 Universal input mains range: 90 - 264 V AC,
frequency 45-65 Hz
 Output voltage: 5 V @ 1 A continuous
operation
 Optoless constant voltage - constant current
output regulation
 Standby mains consumption: < 100 mW @
230 V AC
 Average efficiency: >70%
 EMI: in accordance with EN55022-Class-B
 RoHS compliant
Description
The STEVAL-ISA176V1 evaluation board
implements a 5 W (5 V / 1 A) wide-range mains
battery charger with constant voltage/constant
current, tailored for AC-DC chargers for mobile
phones and adapters or other hand-held
equipment.
The core of the application is the ALTAIR05T-
800, the first “all-primary sensing switching
regulator” of the ALTAIR family.
The IC combines a high-performance, low-
voltage PWM controller chip and an 800 V,
avalanche-rugged power MOSFET in the same
package.
The PWM chip is a quasi-resonant (QR) current
mode controller IC specifically designed for QR
ZVS (zero voltage switching at switch turn-on)
flyback converters.
The device is capable of providing constant
output voltage (CV) and constant output current
(CC) regulation using primary-sensing feedback.
This eliminates the need for the optocoupler, the
secondary voltage reference and the current
sensor, while still maintaining quite accurate
regulation.
In addition, it is possible to compensate the
voltage drop on the output cable to improve CV
regulation on the externally accessible terminals.
Extremely low consumption under no load
conditions is ensured thanks to controlled burst
mode operation that, along with the built-in high
voltage startup circuit and the low operating
current of the device, helps minimize the residual
input consumption. Although an auxiliary winding
is required in the transformer to correctly perform
CV/CC regulation, the chip can be powered
directly from the rectified mains. This is useful
particularly during CC regulation, where the
flyback voltage is generated by the winding
drops.
October 2015
DocID028457 Rev 1
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