OB2202.pdf 데이터시트 (총 14 페이지) - 파일 다운로드 OB2202 데이타시트 다운로드

No Preview Available !

OB2202
Quasi-Resonant Flyback PWM Controller
GENERAL DESCRIPTION
OB2202 is a highly integrated Quasi-Resonant (QR)
controller optimized for high performance offline
flyback converter applications.
At normal load condition, it operates in QR mode
with minimum drain voltage switching. To meet the
CISPR-22 EMI starting at 150KHz, the maximum
switching frequency is internally limited to 130KHz.
It operates in PFM mode for high power conversion
efficiency at light load condition. When the loading is
very small, the IC operates in ‘Extended Burst Mode’
to minimize the switching loss. As a result, lower
standby power consumption and higher conversion
efficiency can be achieved.
OB2202 offers comprehensive protection coverage
including Cycle-by-Cycle Current Limiting, VCC
Under Voltage Lockout(UVLO), Programmable
Output Over Voltage Protection(OVP), VCC Clamp,
Gate Clamp, Over Load Protection(OLP), On-chip
Thermal Shutdown, Programmable Soft Start,
Programmable Brownout Protection, Programmable
Over Power Protection (OPP) Compensation, and
External Latch Triggering, Max On-time Limit, etc.
OB2202 is offered in SOP-8 and DIP-8 packages.
FEATURES
Multi-Mode Operation
Quasi-Resonant Operation at Normal Loading
Pulse Frequency Modulation (PFM) Operation at
Light Load
Programmable Brownout Protection and Line
OVP Protection
Burst Mode at No Load
Excellent OPP Compensation
20KHz Minimum Frequency Limit at QR Mode
130KHz Maximum Frequency Limit
Internal Minimum T_off for Ringing Suppression
35us Maximum On Time Limit
50us Maximum Off Time Limit
Internal Leading Edge Blanking
Programmable Soft-start
Cycle-by-cycle Current Limiting
External Latch Triggering
Internal Thermal Shutdown
1A Peak Current Sink/Source Capability
Programmable Output OVP
APPLICATIONS
Offline AC/DC flyback converter for
Power Adaptor and Open-frame SMPS
LCD Monitor/TV/PC/Set-Top Box Power
Supplies
NB/DVD/Portable DVD Power Supplies
TYPICAL APPLICATION
©On-Bright Electronics
-1-
Confidential
OB_DOC_DS_0200

No Preview Available !

OB2202
Quasi-Resonant Flyback PWM Controller
GENERAL INFORMATION
Pin Configuration
The pin map of OB2202 in DIP8 and SOP8 package
is shown as below.
Ordering Information
Part Number
OB2202AP
OB2202CP
OB2202CPA
Description
8 Pin DIP, Pb free in Tube
8 Pin SOP, Pb free in Tube
8 Pin SOP, Pb free in T&R
Note: All Devices are offered in Pb-free Package if not otherwise
noted.
Package Dissipation Rating
Package
DIP8
SOP8
RθJA (°C/W)
90
150
Absolute Maximum Ratings
Parameter
VCC Zener Clamp Voltage
VCC Clamp Continuous
Current
SS Input Voltage
FB Input Voltage
CS Input Voltage
DEM Input Voltage
BO Input Voltage
Min/Max Operating Junction
Temperature TJ
Min/Max Storage Temperature
Tstg
Lead Temperature (Soldering,
10secs)
Value
31 V
10 mA
-0.3 to 7V
-0.3 to 7V
-0.3 to 7V
-0.3 to 7V
-0.3 to 7V
-20 to 150 oC
-55 to 150 oC
260 oC
Note: Stresses beyond those listed under “absolute maximum
ratings” may cause permanent damage to the device. These are
stress ratings only, functional operation of the device at these or
any other conditions beyond those indicated under “recommended
operating conditions” is not implied. Exposure to absolute
maximum-rated conditions for extended periods may affect device
reliability.
©On-Bright Electronics
-2-
Confidential
OB_DOC_DS_0200

No Preview Available !

Marking Information
SOP8
OB2202
Quasi-Resonant Flyback PWM Controller
DIP8
LT YWW
OB2202CP
s
Y: Year Code (0-9)
WW: Week Code (1-52)
C: SOP8
P:lead-free
s: internal code
LT YWW
OB2202AP
s
Y: Year Code (0-9)
WW: Week Code (1-52)
A: DIP8
P:lead-free
s: internal code
TERMINAL ASSIGNMENTS
Pin Num Pin Name
1 SS
2 FB
3 CS
4 GND
5 GATE
6 VCC
7 DEM
8 BO
I/O Description
I/O Soft-start programming pin. Program the soft-start time with a capacitor
connected to GND. After soft-start, the pin’s voltage is clamped at 2V. This
pin is also used as external latch input, latch will be triggered when SS pin
voltage higher than 3.75V.
I/O Feedback input pin. PWM duty cycle is determined by voltage level into this
pin and current-sense signal level at Pin 3. The voltage level at this pin also
controls the mode of operation in one of the three modes: quasi-resonant
(QR), pulse frequency modulation mode (PFM) and burst mode (BM).
I Current sense input.
P Ground for internal circuitry.
O Totem-pole gate drive output for power MOSFET.
P Chip DC power supply pin.
I/O Input from auxiliary winding for demagnetization timing. Also this pin is
used for output over voltage protection (Load OVP).
I/O Brownout and Line OVP detection pin. Connect a resistor divider from line
voltage to this pin to detect line voltage. If this pin drops below 0.5V and
lasts for 50ms, brownout protection will be triggered and PWM output will
be disabled. This pin is also used as line OVP sense input
©On-Bright Electronics
-3-
Confidential
OB_DOC_DS_0200

No Preview Available !

OB2202
Quasi-Resonant Flyback PWM Controller
BLOCK DIAGRAM
VCC
6
Trimmed
Voltage/Current
Reference
Internal reference
UVLO
POR
DEM
7
Regulator
Internal
supply
Valley
detector
Load OVP
Timer,
PFC control,
Logic,
&
Fault
Management
SQ
R Qb
OLP
Latch
Soft Start
1 SS
Brownout &
Line OVP
4 GND
8 BO
Soft
Driver
GATE
5
On chip
Thermal shutdown
Mode selection
FB
2
BO
LEB
CS
3
RECOMMENDED OPERATING CONDITION
Symbol
VCC
TA
Parameter
VCC Supply Voltage
Operating Ambient Temperature
Min Max Unit
11 28 V
-20 85
oC
©On-Bright Electronics
-4-
Confidential
OB_DOC_DS_0200

No Preview Available !

OB2202
Quasi-Resonant Flyback PWM Controller
ELECTRICAL CHARACTERISTICS
(TA = 25OC, VCC=16V, if not otherwise noted)
Symbol
Parameter
Test Conditions
Min Typ Max Unit
Supply Voltage (VCC) Section
Istartup
VCC Start up Current VCC =15V, Measure
current into VCC
5 15 uA
I_VCC_quiet
Operation Current
without switching
VCC=12V, FB is floating,
1
mA
I_VCC_operation Operation current
with switching
VCC=12V, Fsw=130KHz,
1nF load at GATE
4 6 mA
UVLO(ON)
VCC Under Voltage
Lockout Enter
8 9 10 V
UVLO(OFF)
VCC Under Voltage
Lockout Exit
(Startup)
14 15 16 V
OVP(ON)
VCC Over Voltage
Protection Enter
31 V
VCC_Clamp
VCC Zener Clamp
Voltage
I(VCC ) = 5 mA
32 V
Feedback Input Section(FB Pin)
AVCS
PWM Input Gain
VFB_Open
FB Open Voltage
ΔVFB /ΔVcs
3 V/V
4.8 V
IFB_Short
FB pin short circuit
current
VTH_PFM_on
PFM mode on
threshold
VTH_PFM_off
PFM mode off
threshold
VTH_BM_on
Burst Mode on
threshold
VTH_BM_off
Burst Mode off
threshold
VTH_PL
Power Limiting FB
Threshold Voltage
TD_PL
Power limiting
Debounce Time
ZFB_IN
Input Impedance
Current Sense Input(CS Pin) Section
T_blanking
CS Input Leading
Edge Blanking Time
ICS Internal source
current to CS pin for
OPP compensation
TD_OC
Over Current
Detection and Control
Delay
Demagnetization Detection Section
VTH_DEM
Demagnetization
comparator threshold
voltage
VTH_DEM_hyst Hysteresis for DEM
Short FB pin to GND,
measure current
0V<V(BO)<0.4V
0.4V<V(BO)<1.2V
1.2V<V(BO)<3V
CL=1nf at GATE,
1.5 mA
1.8 V
1.2 V
1.6 V
1.0 V
4.4 V
80 mSec
4 Kohm
350 nSec
0
100×[V(BO)-0.4]
80+28.6×[V(BO)-1.2]
100
uA
uA
uA
nSec
10 75 30 mV
20 mV
©On-Bright Electronics
-5-
Confidential
OB_DOC_DS_0200