OB2362C
Adaptive Multi-Mode PWM Controller
GENERAL DESCRIPTION
FEATURES
OB2362C is a highly integrated current mode
PWM control IC optimized for high performance,
low standby power and cost effective offline
flyback converter applications.
At full loading, the IC operates in fixed frequency
(65KHz) mode. When the loading goes low, it
operates in Green mode with valley switching for
high power conversion efficiency. When the load is
very small, the IC operates in ‘Extended Burst
Mode’ to minimize the standby power loss. As a
result, high conversion efficiency can be achieved
in the whole loading range.
VCC low startup current and low operating current
contribute to a reliable power on startup and low
standby design with OB2362C.
OB2362C offers comprehensive protection
coverage with auto-recovery including Cycle-byCycle current limiting (OCP), over load protection
(OLP), VCC under voltage lockout (UVLO), over
temperature protection (OTP), and over voltage
protection (OVP). Excellent EMI performance is
achieved with On-Bright proprietary frequency
shuffling technique.
The tone energy at below 23KHz is minimized in
the design and audio noise is eliminated during
operation.
OB2362C is offered in SOT23-6 package.
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APPLICATIONS
■
Power on soft start reducing MOSFET Vds
stress
Multi-Mode Operation
65KHz fixed frequency mode @ Full Load
Valley switching operation @ Green mode
Burst Mode @ Light Load & No Load
Frequency shuffling for EMI
Extended burst mode control for improved
efficiency and low standby power design
Audio noise free operation
Comprehensive protection coverage
o VCC Under Voltage Lockout with
hysteresis (UVLO)
o VCC Over Voltage Protection (VCC OVP)
o Cycle-by-cycle over current threshold
setting for constant output power limiting
over universal input voltage range
o Over Load Protection (OLP) with autorecovery
o Brownout protection with auto-recovery
o Line Over Voltage Protection(Line OVP)
o Output Over Voltage Protection(Output
OVP) with auto-recovery, and the OVP
triggered voltage can be adjusted by the
resistors connected between auxiliary
winding and ground
o Output diode short protection with autorecovery
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Offline AC/DC flyback converter for
■ General power supply
■ Power Adapter
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TYPICAL APPLICATION
©On-Bright Electronics
Confidential
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Datasheet
OB_DOC_DS_2362CA0
OB2362C
Adaptive Multi-Mode PWM Controller
Absolute Maximum Ratings
Parameter
Value
Pin Configuration
1
6
Gate
FB
2
5
VCC
DEM
3
4
VOVP-1V
FB Input Voltage
-0.3 to 7V
CS Input Voltage
-0.3 to 7V
DEM Input Voltage
-0.3 to 7V
Min/Max Operating
Junction Temperature TJ
CS
Operating Ambient
Temperature TA
-40 to 85 ℃
Min/Max Storage
Temperature Tstg
-55 to 150 ℃
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Ordering Information
Part Number
Description
OB2362CMP
SOT23-6, Pb-free in T&R
-40 to 150 ℃
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GND
VCC DC Supply Voltage
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GENERAL INFORMATION
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Lead
Temperature
260 ℃
(Soldering, 10secs)
Note: Stresses beyond those listed under
Package Dissipation Rating
Package
RJA(℃/W)
SOT23-6
200
“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.
Recommended operating condition
Symbol Parameter
Range
VCC
VCC Supply Voltage
12 to 26V
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OB2362C
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High Performance Current Mode PWM
Controller
X
Package
M:SOT23-6
X
Package Pb-free
P:Pb-free
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Marking Information
362YWW
. ZZZC S
Y:Year Code
WW:Week Code(01-52)
ZZZ: Lot code
C:Character Code
S: Internal code
©On-Bright Electronics
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Datasheet
OB_DOC_DS_2362CA0
OB2362C
Adaptive Multi-Mode PWM Controller
TERMINAL ASSIGNMENTS
I/O
Description
VCC
P
Power Supply
CS
I
Current sense input
Gate
O
Totem-pole gate driver output for power MOSFET
GND
P
Ground
DEM
I
Multiple functions pin. Connecting two resistors from Vaux to ground can adjust
output OVP trigger voltage, Brown-in/Brown-out trigger voltage, Line OVP trigger
voltage and detect transformer core demagnetization.
FB
I
Feedback input pin. The PWM duty cycle is determined by voltage level into this pin
and the current-sense signal at Pin CS.
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Pin Name
©On-Bright Electronics
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Datasheet
OB_DOC_DS_2362CA0
OB2362C
Adaptive Multi-Mode PWM Controller
FUNCTIONAL BLOCK DIAGRAM
S
S
Q
Logic
Control
Soft Driver
R
OVP
AVDD
Diode short
Vref&
Iref
OSC
Diode
short
GND
Vocp
Slope
compensation
LEB
CS
OLP
AVDD
PWM
Comparator
Multi
Mode
Control
Temp
sense
Timer
OLP
FB
OTP
BO
DEM
OCP
Comparator
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Internal
blocks
Diode
short
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VCC
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OVP
UVLO
GATE
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Valley
OVP
Line OVP
EX OVP
Valley
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Valley
Detector
©On-Bright Electronics
Confidential
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Datasheet
OB_DOC_DS_2362CA0
OB2362C
Adaptive Multi-Mode PWM Controller
ELECTRICAL CHARACTERISTICS
(TA = 25℃, VCC=18V, unless otherwise noted)
Symbol
Parameter
Supply Voltage (VDD)
Operation Current
I_VCC_Burst
Burst Current
UVLO(OFF)
mA
0.6
0.7
mA
6.8
7.3
7.8
V
16
17
18
V
10
FB=3V,CS=0V. Slowly
VCC Over Voltage Protection
OVP
ramp VCC, until no 26.5 28
threshold voltage
gate switching.
Feedback Input Section(FB Pin)
VFB_Open
VFB Open Loop Voltage
5.1
Avcs
PWM input gain ∆VFB/∆VCS
3.5
Maximum
duty Max
duty
cycle
@
77
80
cycle
VCC=18V,VFB=3V,VCS=0V
The threshold enter green
Vref_green
2.1
mode
Vref_burst_H
The threshold exits burst mode
1.33
The threshold enters burst
Vref_burst_L
1.23
mode
Short FB pin to GND
IFB_Short
FB pin short circuit current
0.21
and measure current
Open loop protection, FB
VTH_OLP
4.4
Threshold Voltage
Open loop protection,
Td_OLP
60
Debounce Time
ZFB_IN
Input Impedance
30
Current Sense Input(CS Pin)
SST_CS
Soft start time for CS peak
2.5
T_blanking
Leading edge blanking time
300
From Over Current
Over Current Detection and Occurs till the Gate
Td_OC
90
Control Delay
driver output start to
turn off
Internal
Current
Limiting
VTH_OC
0.43 0.45
Threshold Voltage with zero
duty cycle
VTH_OC_Clamp
OCP CS voltage clamper
0.72
DEM pin
Ibrown-in
Brown-in threshold current
110
Ibrown-out
Brown-out threshold current
95
100
V
29.5 V
V
V/V
83
V
ht
V
mA
V
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%
V
ms
KΩ
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©On-Bright Electronics
uA
3.1
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Vpull-up
VCC Under Voltage Lockout
Enter
VCC Under Voltage Lockout
Exit (Recovery)
Pull-up PMOS active
5
2.6
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UVLO(ON)
2
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I_VCC_Operation
VCC=UVLO(OFF)-1V,
measure
leakage
current into VCC
VDD=18V,CS=4V,
FB=3.5V,measure
I(VCC)
CS=0V,FB=0.5V,
measure I(VCC)
Max Unit
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VCC Start up Current
Min Typ.
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Istartup
Test Conditions
ms
ns
ns
0.47 V
V
105
uA
uA
Datasheet
OB_DOC_DS_2362CA0
OB2362C
Adaptive Multi-Mode PWM Controller
Voutput_ovp
Td_output_ovp
In-chip OTP
OTP enter
25
29
33
ms
405
440
120
475
uA
ms
2.85 3
3.15 V
6
Cycles
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I_lineovp
Td_lineovp
Brown-out protection debounce
Time
Line OVP threshold current
Line OVP debounce time
Voltage
threshold
for
adjustable output OVP
Output OVP debounce time
OTP exit
Oscillator
VDD=18V,FB=3V,
CS=0V
150
℃
120
℃
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Td_BO
Normal Oscillation Frequency
60
65
70
KHz
ᇞf_OSC
Frequency jittering
+/-6
%
F_shuffling
Shuffling frequency
32
Hz
ᇞf_Temp
Frequency
Stability
1
%
ᇞf_VCC
Frequency Voltage Stability
1
%
F_Burst
Gate driver
Burst Mode Switch Frequency
23
KHz
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Output low level @ VDD=18V,
Io=5mA
Output high level @ VCC=18V,
Io=20mA
Output clamp voltage
Output rising time 1.2V ~ 10.8V
@ CL=1000pF
Output falling time 10.8V ~ 1.2V
@ CL=1000pF
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VOH
Temperature
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VOL
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FOSC
V_clamping
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T_r
T_f
©On-Bright Electronics
Confidential
6
1
6
V
V
11
V
100
ns
30
ns
Datasheet
OB_DOC_DS_2362CA0
OB2362C
Adaptive Multi-Mode PWM Controller
CHARACTERIZATION PLOTS
VDD = 18V, TA = 25℃ condition applies if not otherwise noted.
UVLO(OFF)(V) vs Tem perature
7.20
7.00
-40
-10
20
50
80
狮
7.60
7.40
19.00
18.20
17.40
16.60
15.80
15.00
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8.00
7.80
UVLO(OFF)(V)
UVLO(ON)(V)
UVLO(ON)(V) vs Tem perature
-40
110 140
-10
-10
20
50
80
110 140
0.9
0.8
0.7
0.6
0.5
0.4
0
10
20
Temperature(℃)
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OVP(V)
ht
Br
ig
Vth_ocp(V)
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-10
20
50
60
70
29.30
28.94
28.58
28.22
27.86
27.50
50
80
110 140
-40
Temperature(℃)
©On-Bright Electronics
40
OVP(V) vs Tem perature
0.400
-40
30
Duty(%)
Vth_ocp(V) vs Tem perature
0.500
0.480
0.460
0.440
0.420
110 140
Duty vs Vth_oc
Vth_oc(V)
Fosc_nom(Khz)
-40
80
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Fosc_nom (Khz) vs Tem perature
68.00
66.00
64.00
62.00
60.00
50
Temperature(℃)
Temperature(℃)
70.00
20
-10
20
50
80
110 140
Temperature(℃)
Confidential
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Datasheet
OB_DOC_DS_2362CA0
OB2362C
Adaptive Multi-Mode PWM Controller
OPERATION DESCRIPTION
狮
OB2362C is a highly integrated current mode
PWM control IC optimized for high performance,
low standby power and cost effective offline
flyback converter applications. The ‘extended
burst mode’ control greatly reduces the standby
power consumption and helps the design easier to
meet the international power conservation
requirements.
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Startup Current and Start up Control
Startup current of OB2362C is designed to be
very low so that VCC could be charged up above
UVLO threshold level and device starts up quickly.
A large value startup resistor can therefore be
used to minimize the power loss yet achieve a
reliable startup in application.
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Multi Mode Operation for High Efficiency
OB2362C is a multi mode controller. The
controller changes the mode of operation
according to the FB pin voltage. At the normal
operating condition, the IC operates in traditional
fix frequency （65KHz）PWM mode.
As the output load current is decreased , the IC
enter into green mode smoothly from the PWM
mode. In this mode , the switching frequency will
start to linearly decrease from 65KHz to 23KHz,
meanwhile the valley turn on can be realized by
monitoring the voltage activity on auxiliary
windings through the DEM pin. So the switching
loss is minimized and the high conversion
efficiency can be achieved.
At light load or no load condition, most of the
power dissipation in a switching mode power
supply is from switching loss of the MOSFET, the
core loss of the transformer and the loss of the
snubber circuit. The magnitude of power loss is in
proportion to the switching frequency. Lower
switching frequency leads to the reduction on the
power loss and thus conserves the energy.
The switching frequency is internally adjusted at
no load or light load condition. The switch
frequency reduces at light/no load condition to
improve the conversion efficiency. At light load or
no load condition, the FB input drops below
Vref_burst_L (the threshold enter burst mode) and
device enters Burst Mode control. The Gate drive
output switches when FB input rises back to
Vref_burst_H (the threshold exit burst mode).
Otherwise the gate drive remains at off state to
minimize the switching loss and reduces the
standby power consumption to the greatest
extend.
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Operating Current
The Operating current of OB2362C is low at
2.5mA (typical). Good efficiency is achieved with
OB2362C low operation current together with the
‘extended burst mode’ control features.
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Soft Start
OB2362C features an internal 2.5ms (typical) soft
start to soften the electrical stress occurring in the
power supply during startup. It is activated during
the power on sequence. As soon as VCC reaches
UVLO(OFF), the CS peak voltage is gradually
increased from 0.05V to the maximum level.
Every restart up is followed by a soft start.
Frequency shuffling for EMI improvement
The frequency shuffling (switching frequency
modulation) is implemented in OB2362C. The
oscillation frequency is modulated so that the tone
energy is spread out. The spread spectrum
minimizes the conduction band EMI and therefore
eases the system design.
©On-Bright Electronics
Demagnetization Detection
The transformer core demagnetization is detected
by monitoring the voltage activity on the auxiliary
windings through DEM pin. This voltage features
a flyback polarity. After the on time (determined by
the CS voltage and FB voltage), the switch is off
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Datasheet
OB_DOC_DS_2362CA0
OB2362C
Adaptive Multi-Mode PWM Controller
and the flyback stroke starts. After the flyback
stroke, the drain voltage shows an oscillation with
a frequency of approximately 1 / 2
where
Multiple Functions of Brown-in/Brown-out,
Line OVP in/Line OVP out and Output OVP
When the power MOSFET is turn on, the voltage
on auxiliary windings is negative which make our
Brown-in/Brown-out protection feasible.
L pCd ,
L p is the primary self inductance of
primary winding of the transformer and Cd is the
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capacitance on the drain node.
The typical detection level is fixed at -50mV at the
DEM pin. Demagnetization is recognized by
detection of a possible “valley” when the voltage
at DEM is below -50mV in falling edge.
I AUX
R1: The resistor connected from DEM to AUX.
R2: The resistor connected from DEM to ground.
When system starts up, if IAUX < Ibrown_in, Brown-in
auto-recovery protection is triggered after 2 Gate
cycles debounce. When the system enters the
normal operation mode, if IAUX < Ibrown_out, Brownout auto-recovery protection is triggered after
29ms debounce.
When the system enters the normal operation
mode, if IAUX > ILine_OVP, Line OVP auto-recovery
protection is triggered after 120ms debounce.
For output OVP detection, when Gate is off, VDEM
is equal to VAUX*R2/(R1+R2). If VDEM is larger
than 3V (typical), OVP auto-recovery protection is
triggered after 6 Gate cycles debounce. By
selecting proper R1 and R2 resistance, output
OVP level can be programmed.
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Current Sensing and Leading Edge Blanking
Cycle-by-Cycle current limiting is offered in
OB2362C current mode PWM control. The switch
current is detected by a sense resistor into the CS
pin. An internal leading edge blanking circuit
chops off the sensed voltage spike at initial
internal power MOSFET on state due to snubber
diode reverse recovery and surge gate current of
power MOSFET. The current limiting comparator
is disabled and cannot turn off the internal power
MOSFET during the blanking period. The PWM
duty cycle is determined by the current sense
input voltage and the FB input voltage.
V AUX
Internal Synchronized Slope Compensation
Built-in slope compensation circuit adds voltage
ramp into the current sense input voltage for PWM
generation. This greatly improves the close loop
stability at CCM and prevents the sub-harmonic
oscillation and thus reduces the output ripple
voltage.
3 * ( R1 R 2)
R2
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Protection Controls
Good power supply system reliability is achieved
with auto-recovery protection features including
Cycle-by-Cycle current limiting (OCP), Under
Voltage Lockout on VDD (UVLO), Over
Temperature
Protection
(OTP),
Brownout
Protection, VCC and output Over Voltage
Protection (OVP).
With On-Bright proprietary technology, the OCP is
line voltage compensated to achieve constant
output power limit over the universal input voltage
range.
At overload condition when FB input voltage
exceeds power limit threshold value for more than
Td_OLP, control circuit reacts to shut down the
converter. It restarts when VDD voltage drops
below UVLO limit.
Driver
The power MOSFET is driven by a dedicated gate
driver for power switch control. Too weak the gate
driver strength results in higher conduction and
switch loss of MOSFET while too strong gate
driver strength results the compromise of EMI.
A good tradeoff is achieved through the built-in
totem pole gate design with right output strength
and dead time control. The low idle loss and good
EMI system design is easier to achieve with this
dedicated control scheme.
©On-Bright Electronics
0.1 0.1 V AUX
R2
R1
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Datasheet
OB_DOC_DS_2362CA0
OB2362C
Adaptive Multi-Mode PWM Controller
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PACKAGE MECHANICAL DATA
Symbol
O
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A
A1
A2
b
c
D
E
E1
e
e1
L
θ
Dimensions In Millimeters
Min
Max
1.000
1.450
0.000
0.150
0.900
1.300
0.300
0.500
0.080
0.220
2.800
3.020
1.500
1.726
2.600
3.000
0.950 (BSC)
1.800
2.000
0.300
0.600
0º
8º
©On-Bright Electronics
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Dimensions In Inches
Min
Max
0.039
0.057
0.000
0.006
0.035
0.051
0.012
0.020
0.003
0.009
0.110
0.119
0.059
0.068
0.102
0.118
0.037 (BSC)
0.071
0.079
0.012
0.024
0º
8º
Datasheet
OB_DOC_DS_2362CA0
OB2362C
Adaptive Multi-Mode PWM Controller
IMPORTANT NOTICE
狮
RIGHT TO MAKE CHANGES
On-Bright Electronics Corp. reserves the right to make corrections, modifications, enhancements,
improvements and other changes to its products and services at any time and to discontinue any product
or service without notice. Customers should obtain the latest relevant information before placing orders
and should verify that such information is current and complete.
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WARRANTY INFORMATION
On-Bright Electronics Corp. warrants performance of its hardware products to the specifications
applicable at the time of sale in accordance with its standard warranty. Testing and other quality control
techniques are used to the extent it deems necessary to support this warranty. Except where mandated
by government requirements, testing of all parameters of each product is not necessarily performed.
On-Bright Electronics Corp. assumes no liability for application assistance or customer product design.
Customers are responsible for their products and applications using On-Bright’s components, data sheet
and application notes. To minimize the risks associated with customer products and applications,
customers should provide adequate design and operating safeguards.
LIFE SUPPORT
On-Bright Electronics Corp.’s products are not designed to be used as components in devices intended to
support or sustain human life. On-bright Electronics Corp. will not be held liable for any damages or
claims resulting from the use of its products in medical applications.
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MILITARY
On-Bright Electronics Corp.’s products are not designed for use in military applications. On-Bright
Electronics Corp. will not be held liable for any damages or claims resulting from the use of its products in
military applications.
©On-Bright Electronics
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Datasheet
OB_DOC_DS_2362CA0
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湘ICP备2023018690号
