High Precision Low Cost Power Switch
OB2225N
GENERAL DESCRIPTION
OB2225N is a high performance, high precision
and low cost PWM Power switch for non-isolated
buck and buck-boost application. It combines a
dedicated current mode PWM controller with a
high voltage power Mosfet in SOP8 package. Its
built-in error amplifier is optimized for good
overshoot and dynamic response for low cost and
component count. With precise inner resistor
divider, precise reference of EA
，
constant
voltage regulation of 12V at universal AC input can
be guaranteed. Frequency reduction and burst
mode control is implemented for high efficiency at
light load. Good EMI performance is achieved with
On-Bright
proprietary
frequency
shuffling
technique and soft gate driver design. Low startup
current and low operating current contribute to a
reliable power on startup and low standby power
consumption with OB2225N.
OB2225N offers power on soft start control and
protection coverage with auto-recovery features
including cycle-by-cycle current limiting, output
short circuit protection, on-chip Over Temperature
Protection (OTP), VDD Over Voltage Protection
(OVP), Over Loading Protection(OLP) and VDD
Under Voltage Lockout Protection (UVLO).
The tone energy at below 20KHz is minimized in
the design so that audio noise is eliminated during
operation.
OB2225N is offered in SOP8 package.
FEATURES
Universal AC input range and 12V output
voltage
Low cost and less BOM for buck and buck-
boost applications
Current mode control
40kHz (typical) maximum switching frequency
Frequency-reduction and burst mode control
for high efficiency
Frequency shuffling for EMI improvement
Power on soft-start
Built-in Leading Edge Blanking (LEB)
Cycle-by-cycle current limiting
Output short-circuit protection
VDD Under Voltage Lockout with Hysteresis
VDD OVP
Over Loading Protection
On-Chip OTP
APPLICATIONS
Low power AC/DC offline SMPS for
Small home appliance
Linear regulator/RCC replacement
TYPICAL APPLICATION
Drain
Drain
Drain
Drain
AC IN
CS
NC
GND
VDD
DC
OUT
©On-Bright Electronics
Confidential
-1-
OB_DOC_DS_2225NA0
High Precision Low Cost Power Switch
OB2225N
GENERAL INFORMATION
Pin Configuration
The pin map is shown as below for SOP8
Output Power Table
Topology
90~264Vac
176~264Vac
(open frame)
(open frame)
VDD
1
8
Drain
Buck /
350mA
400mA
Buck-Boost
Note:
Maximum continuous power with drain pattern
2
connected 100mm PCB copper clad, at 50℃ ambient.
Topology
90~264Vac
176~264Vac
(open frame)
GND
2
OB2225N
7
Drain
(open frame)
NC
3
6
Drain
Buck /
300mA
350mA
Buck-Boost
Note:
Maximum continuous power with drain pattern
connected 100mm
2
PCB copper clad, at 85℃ ambient.
CS
4
5
Drain
Ordering Information
Part Number
Description
OB2225NCP
SOP8, Pb-free, Tube
OB2225NCPA
SOP8, Pb-free, T&R
Package Dissipation Rating
Package
RθJA (℃/W)
SOP8
90
Note:
Drain Pin Connected 100mm
2
PCB copper
clad.
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.
Absolute Maximum Ratings
Parameter
Drain Voltage(off state)
VDD Voltage
CS Input Voltage
Min/Max Operating Junction
Temperature T
J
Operating Ambient
Temperature T
A
Min/Max Storage
Temperature T
stg
Lead Temperature
(Soldering, 10secs)
Note:
Stresses beyond those
Value
-0.3V to Bvdss
-0.3 to 20V
-0.3 to 7V
-40 to 150
℃
-40 to 85
℃
-55 to 150
℃
260
℃
Recommended Operating Condition
Symbol
Parameter
Range
VDD
VDD Supply Voltage
8 to 12V
©On-Bright Electronics
Confidential
-2-
OB_DOC_DS_2225NA0
High Precision Low Cost Power Switch
OB2225N
ELECTRICAL CHARACTERISTICS
(T
A
= 25℃, VDD=12V, if not otherwise noted)
Symbol
Parameter
Supply Voltage (VDD) Section
I_
startup
I
_VDD_op
Standby Current
Operation Current
Test Conditions
VDD=UVLO(off) -1V
Min Typ. Max Unit
10 uA
UVLO_ON
UVLO_OFF
OVP
VDD Under Voltage Lockout Enter
VDD Under Voltage Lockout Exit
Over voltage protection Threshold
Operation supply current
- 1.0 2.0 mA
CS=0V
Operation supply current
0.45 0.6 mA
VDD=13V
VDD falling, gate
6.8 7.2 7.6 V
disappear
VDD rising
12.513.5 14.5 V
Ramp VDD until gate shut
15 16 17 V
down
12.6
V
In
VDD Regulation normal regulation, VDD will be regulated
Voltage
to average of 12.6V
Current Sense Input Section
TLEB
LEB time
Over current detection
Vth_oc
Threshold voltage
Td_oc
OCP propagation delay
Vth_scp
Short Current protection threshold voltage
Vth_flt
CS floating protection threshold voltage
EA Section
Vref
EA reference
Kvdd/vref
VDD divider coefficient
Frequency Section
Freq_Max
IC Maximum frequency
150 200 250 ns
550 575 600 mV
200
0.6 0.7 0.8
0.9 1.0 1.1
ns
V
V
1.441.5 1.56 V
8.5
36 40
44
KHz
f/Freq
Frequency shuffling range
+/-8
%
F_shuffling
Shuffling frequency
Dmax
Maximum Duty Cycle
F_Burst
Burst Mode Switch Frequency
Protection Section
Td_olp
Over Loading Debounce Time
Power MOSFET t
emperature for exiting over
temperature protection
OTP
Power MOSFET t
emperature for entering
over temperature protection
Power Mosfet Section
BVdss
MOSFET Drain-Source Breakdown Voltage
Rdson
On Resistance
Static, Id=0.45A
75
47 50
20
130
135
160
600
53
Hz
%
KHz
ms
℃
℃
V
Ώ
15
©On-Bright Electronics
Confidential
-5-
OB_DOC_DS_2225NA0
stm32/stm8
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