|
|
PDF IW1710 Data sheet ( Hoja de datos )
| Número de pieza | IW1710 | |
| Descripción | Digital PWM Current-Mode Controller | |
| Fabricantes | iWatt | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de IW1710 (archivo pdf) en la parte inferior de esta página. Total 20 Páginas | ||
|
No Preview Available !
iW1710
Digital PWM Current-Mode Controller for Quasi-Resonant Operation
1.0 Features
●● Primary-side feedback eliminates opto-isolators and
simplifies design
●● Quasi-resonant operation for highest overall efficiency
●● EZ-EMI ® design to easily meet global EMI standards
●● Up to 130 kHz switching frequency enables small
adapter size
●● Very tight output voltage regulation
●● No external compensation components required
●● Complies with CEC/EPA no-load power consumption
and average efficiency regulations
●● Built-in output constant-current control with primary-side
feedback
●● Low start-up current (10 µA typical)
●● Built-in soft start
●● Built-in short circuit protection and output overvoltage
protection
●● Optional AC line under/overvoltage protection
●● PFM operation at light load
●● Current sense resistor short protection
●● Overtemperature Protection
2.0 Description
The iW1710 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 at heavy load 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 iW1710 removes the need for secondary
feedback circuitry 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
current limit function enables optimized transformer design
in universal off-line applications over a wide input voltage
range.
The ultra-low operating current at light load ensures that
the iW1710 is ideal for applications targeting the newest
regulatory standards for average efficiency and standby
power.
3.0 Applications
●● Cable/DSL modems, WLAN access points and VOIP
gateways.
L
N
+
+ VOUT
RTN
Rev. 2.5
+
Optional
NTC
Thermistor
1 NC
VCC 8
2 VSENSE OUTPUT 7
3 VIN
ISENSE 6
4 SD
GND 5
U1
iW1710
Figure 3.1 : Typical Application Circuit
iW1710
November 27, 2012
Page 1
1 page  
iW1710
Digital PWM Current-Mode Controller for Quasi-Resonant Operation
7.0 Typical Performance Characteristics
9.0
6.0
3.0
0.00.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0
VCC (V)
Figure 7.1 : VCC vs. VCC Supply Start-up Current
0.3 %
-0.3 %
-0.9 %
-1.5 %
-50
-25 0 25 50 75 100
Ambient Temperature (°C)
125
Figure 7.3 : % Deviation of Switching Frequency to
Ideal Switching Frequency vs. Temperature
12.2
12.0
11.8
11.6-50
-25 0
25 50 75 100 125
Ambient Temperature (°C)
Figure 7.2 : Start-Up Threshold vs. Temperature
1.548
1.538
1.528
1.518-50
-25 0 25 50 75 100
Ambient Temperature (°C)
125
Figure 7.4 : Internal Reference vs. Temperature
Rev. 2.5
iW1710
November 27, 2012
Page 5
5 Page 
iW1710
Digital PWM Current-Mode Controller for Quasi-Resonant Operation
10.0 Design Example
10.1 Design Procedure
This design example gives the procedure for a flyback
converter using iW1710. Refer to Figure 12.1 for the
application circuit. The design objectives for this adapter are
given in table 10.1. It meets UL, IEC, and CEC requirements.
Determine the Design Specifications
(Vout, Iout_max, Vin_max, Vin_min, ƒline, Ripple specification)
Determine Part Number
Determine Rvin Resistors
Determine Turns Ratio
Determine Operating VinTon Limit
Determine Magnetizing Inductance
Determine Primary Turns
Determine Secondary Turns
Determine Bias Turns and Vcc Capacitance
Determine Vsense Resistors
Parameter
Input Voltage
Frequency
No Load Input
Output Voltage
Output Current
Output Ripple
Power Out
EPA 2.0
Efficiency
Symbol
VIN
fIN
PIN
VOUT(Cable)
IOUT
VRIPPLE
POUT
h
Range
85 - 264 VRMS
47 - 64 Hz
100 mW
12.0 V
1.2 A
< 100 mV
15 W
80%
Table 10.1 : iW1710 Design Specification Table
10.2 Determine Part Number
Based on design specifications, choose the most suitable
part for the design. For more information on the options see
section 14.0.
Use equation 10.1 for VOUT in the following calculations,
where VFD is the forward voltage of the output diode.
VOUT = VOUT (Cable) + VCableDrop + VFD
(10.1)
For this example there is no cable so VCableDrop is 0 V ,
assuming VFD is 0.5, VOUT is:
VOUT= 12.0V + 0V + 0.5V= 12.5V
No Can you wind this transformer ?
Yes
Determine Current Sensing Resistor
Determine Input Bulk Capacitance
Determine Output Capacitance
Determine Snubber Network
Determine Current Sensing Filter
Finish
Figure 10.1 : iW1710 Design Flow Chart
10.3 Input Selection
VIN resistors are chosen primarily to scale down the input
voltage for the IC. The default scale factor for the input
voltage in the IC is 0.0043 and the internal impedance of
this pin is ZIN (25 kW). Therefore, the VIN resistors should
equate to:
=RVin
Z IN
0.0043
−
Z IN
(10.2)
From equation 10.2, ideally RVin should be 5.79 MW. A lower
value of RVin can decrease the startup time of the power
supply. The value of RVin affects the (VINTON) limits of the IC.
(VIN
⋅ TON
)limit
=0.0043×
720V
(Z IN
RVin
⋅ ms
+ ZIN
)
(10.3)
( )VIN ⋅TON PFM
=0.0043×
135V
(Z IN
RVin
⋅ ms
+ ZIN
)
(10.4)
Rev. 2.5
iW1710
November 27, 2012
Page 11
11 Page | ||
| Páginas | Total 20 Páginas | |
| PDF Descargar | [ Datasheet IW1710.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| IW1710 | Digital PWM Current-Mode Controller | iWatt |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |