iW1760B
Off-Line Digital Green-Mode
Quasi-Resonant PWM Controller
1 Description
The iW1760B is a high performance AC/DC power supply controller which uses digital control
technology to build peak current mode PWM flyback power supplies. The device operates in quasi-
resonant mode to provide high efficiency along with a number of key built-in protection features while
minimizing the external component count, simplifying EMI design and lowering the total bill of material
cost. The iW1760B removes the need for 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. Pulse-by-pulse waveform analysis allows for a loop response that is much
faster than traditional solutions, resulting in improved dynamic load response. The built-in power limit function enables
optimized transformer design in universal off-line applications and allows for a wide input voltage range.
Dialogs innovative proprietary technology ensures that power supplies built with the iW1760B can achieve both the
highest average active efficiency and less than 50mW no-load power consumption in 20W output power range, and
have fast yet smooth start-up with a wide range of capacitive loads with output voltage up to 12V and above, and are
ideal for network and monitor adapter applications.
2 Features
No-load power consumption < 50mW at 230V along Adaptive multi-mode PWM/PFM control improves
AC
with fast dynamic load response and short turn-on efficiency
delay in typical 20W and above adapter applications
Built-in single-point fault protections against output
Primary-side feedback eliminates opto-isolators and short-circuit, output over-voltage and output over-
simplifies design current
Adaptively controlled soft-start enables fast and Dedicated pins for external over-temperature
smooth start-up for a wide range of capacitive loads protection and over-voltage protection, with latch
(from 330F to 6,000F) with output voltage of 12V function available
and above
Tight constant current control enables output current
Tight constant-voltage regulation across line and load limit and over-load protection
range
SmartDefender smart hiccup technology
Intelligent low power management achieves ultra-low helps address issues of soft shorts in cables and
operating current (~250A) at no-load connectors by effectively reducing the average output
power at fault conditions without latch
Proprietary optimized 79kHz maximum PWM switching
frequency with quasi-resonant operation achieves best On-chip internal over-temperature protection
size, efficiency and common mode noise
No audible noise over entire operating range
User-configurable 5-level cable drop compensation
EZ-EMI design enhances manufacturability
3 Applications
Power adapters for network devices and monitors
Universal input AC/DC adapters (15W - 45W)
10-January-2017
Product Summary Rev. 1.2
www.dialog-semiconductor.com 1 of 5 2017 Dialog SemiconductoriW1760B
Off-Line Digital Green-Mode
Quasi-Resonant PWM Controller
L
N
V
OUT
+
+
RTN
U1
iW1760B
1 8
V V
SENSE CC
+
2 7
SD GND
CFG OUTPUT
3 6
4 ASU I 5
SENSE
R
NTC
CDC
Figure 3.1 : iW1760B Typical Application Circuit
(Using Depletion Mode N-FET as Active Start-up Device)
(Achieving < 50mW No-load Power Consumption in 20W Adapter Designs)
L
N
V
OUT
+
+
RTN
U1
iW1760B
1 V V 8
SENSE CC
+
2 SD GND 7
3 CFG OUTPUT 6
4 5
ASU I
SENSE
R
NTC
CDC
Figure 3.2 : iW1760B Typical Application Circuit
(Alternative Circuit without Using Active Start-up Device)
Note: Pin 4 (ASU) can be left unconnected if an active start-up device is not needed in the application circuit.
10-January-2017
Product Summary Rev. 1.2
www.dialog-semiconductor.com 2 of 5 2017 Dialog Semiconductor