iW1818
Off-Line Digital Green-Mode Quasi-Resonant
PWM Controller Integrated with Power BJT
Rev. 1.0Product Summary
© 2016 Dialog Semiconductorwww.dialog-semiconductor.com 1 of 6
15-April-2016
1 Description
The iW1818 is a high performance AC/DC power supply control device that uses digital control
technology to build peak current mode PWM yback power supplies. The device includes an internal
power BJT, operates in quasi-resonant mode, and includes key built-in protection features. This
combination of features and integration simplies design, improves efciency, reduces EMI and lowers
the bill of material cost.
The iW1818 features a distinctive soft-start scheme, which allows for fast and yet smooth start-up with
both small and large capacitive loads. It removes the need for a secondary feedback circuit while achieving excellent
line and load regulation. It also eliminates the need for loop compensation components while maintaining stability over
all operating conditions. The pulse-by-pulse waveform analysis allows for fast dynamic load response. The built-in
power limit function enables optimized transformer design for a wide input voltage range.
Dialog’s innovative proprietary technology ensures that power supplies built with the iW1818 can achieve both the
highest average efciency and less than 50mW no-load power consumption; they also have fast yet smooth start-up
2 Features
● Targeted at 10W to 12W AC/DC applications with
<50mW no-load power consumption at 230V
AC
and
fast dynamic response
● AccuSwitch
TM
technology with integrated 800V
bipolar junction transistor (BJT)
● Adaptively controlled soft-start enables fast and
smooth start-up for a wide range of capacitive loads
(from 330μF to 6,000μF) with output voltage of 5V to
12V and above
● Very tight constant voltage and constant current
regulation over entire operating range
● PrimAccurate
TM
primary-side feedback eliminates
opto-isolator and simplies design
● EZ-EMI
®
design enhances manufacturability
3 Applications
● Network power adapters for ADSL, wireless access
points and routers
● AC/DC adaptor for set top box
● AC/DC power supplies for home appliances
● Intrinsically low common mode noise
● Optimized 72kHz maximum PWM switching
frequency achieves best size and efciency
● Adaptive multi-mode PWM/PFM control improves
efciency
● Quasi-resonant operation for highest overall
efciency
● Dynamic base current control
● No external loop compensation components required
● Built-in single-point protections against output short-
circuit, output low impedance, and output overvoltage
● Built-in over-temperature protection (OTP)
● No audible noise over entire operating range
