GENERAL DESCRIPTION
OB2262 is a highly integrated current mode PWM
control IC optimized for high performance, low
standby power and cost effective offline flyback
converter applications in sub 30W range.
PWM switching frequency at normal operation is
externally programmable and trimmed to tight range.
At no load or light load condition, the IC operates in
extended ‘burst mode’ to minimize switching loss.
Lower standby power and higher conversion
efficiency is thus achieved.
VDD low startup current and low operating current
contribute to a reliable power on startup design with
OB2262. A large value resistor could thus be ud in
the startup circuit to minimize the standby power.
The internal slope compensation improves system
large signal stability and reduces the possible sub-
harmonic oscillation at high PWM duty cycle output.
Leading-edge blanking on current n(CS) input
removes the signal glitch due to snubber circuit diode
rever recovery and thus greatly reduces the external
component count and system cost in the design.
The tone energy at below 20KHZ is minimized in the
design and audio noi is eliminated during operation.
OB2262 is offered in SOT23-6, SOP-8 and DIP-8
packages.
FEATURES
■ Extended Burst Mode Control For Improved
Efficiency and Minimum Standby Power Design
■ Audio Noi Free Operation
■ External Programmable PWM Switching
Frequency
■ Internal Synchronized Slope Compensation
宣风
■ Low VDD Startup Current and Low Operating
Current (1.4mA)
■ Leading Edge Blanking on Current Sen Input
■ Good Protection Coverage With Auto Self-
Recovery
o VDD Over Voltage Clamp and Under Voltage
Lockout with Hysteresis (UVLO)
o Gate Output Maximum Voltage Clamp (18V)
o On-Bright Proprietary Line Input Compensated
Cycle-by-Cycle Over-current Threshold Setting
For Constant Output Power Limiting Over
GENERAL INFORMATION
Pin Configuration
The OB2262 is offered in SOT23-6, DIP8 and SOP8 packages, shown as below.
Ordering Information Part Number Description
OB2262MP SOT23-6, Pb-free OB2262AP DIP8, Pb-free OB2262CP SOP8, Pb-free
Package Dissipation Rating
Package
R θJA (°C/W)
DIP8 90 SOP8 150
SOT23-6
200
Absolute Maximum Ratings
个人借款借条样板Parameter Value VDD DC Supply Voltage
30 V VDD Zener Clamp Voltage
Note
VDD_Clamp+0.1V
VDD DC Clamp Current 10 mA V FB Input Voltage -0.3 to 7V V SENSE Input Voltage to Sen Pin
-0.3 to 7V V RI Input Voltage to RI Pin -0.3 to 7V Min/Max Operating Junction Temperature T J -20 to 150 o C Min/Max Storage Temperature T stg地丁的功效与作用
-55 to 160 o C Note: VDD_Clamp has a nominal value of 34V.
happydayStress beyond tho listed under “absolute maximum ratings” may cau permanent damage to the device. The are stress ratings only, functional operation of the device at the or any other conditions beyond tho indicated under “recommended operating conditions” is not implied. Exposure to absolute maximum-rated conditions for extended periods may affect device reliability.
Marking Information
TERMINAL ASSIGNMENTS
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Pin Name I/O Description世界名牌大学
Ground
GND P
FB I Feedback input pin. The PWM duty cycle is determined by voltage level into this pin and the current-n signal at Pin 6.
RI I Internal Oscillator frequency tting pin. A resistor connected between RI and GND ts the PWM frequency.
陈翠婷SENSE I Current n input pin. Connected to MOSFET current nsing resistor node.
VDD P Chip DC power supply pin.
GATE O Totem-pole gate drive output for the power MOSFET.
RECOMMENDED OPERATING CONDITION
Unit Symbol Parameter Min
Max
VDD VDD Supply Voltage 10 to 30 V
RI RI Resistor Value 100 Kohm
T A Operating Ambient Temperature -20 to 85 o C
BLOCK DIAGRAM
ELECTRICAL CHARACTERISTICS
(T A = 25O C if not otherwi noted)
Symbol Parameter Test Conditions Min Typ Max Unit
Supply Voltage (VDD) I_VDD_Stup VDD Start up Current
VDD =12.5V, RI=100K Measure Leakage current into VDD
3 20 uA
I_VDD_Ops Operation Current VDD =
16V,
RI=100Kohm, V FB =3V
1.4 mA UVLO(ON) VDD Under Voltage Lockout Enter
7.8 8.8 9.8 V
UVLO(OFF) VDD Under Voltage Lockout Exit (Recovery)
13 14 15 V
VDD_Clamp VDD Zener Clamp Voltage
I VDD = 5 mA 34 V
Feedback Input Section(FB Pin)
A VCS PWM Input Gain ΔV F
B /ΔV cs
2.0 V/V V FB_Open V FB Open Loop Voltage 4.8 V I FB _Short FB pin short circuit current Short FB pin to GND and measure current
1.2 mA
V TH _0D Zero Duty Cycle FB Threshold Voltage VDD = 16V, RI=100Kohm
0.75 V
V TH _PL Power Limiting FB Threshold Voltage
3.7 V
T D _PL Power limiting Debounce Time
35 mSec
Z FB _IN Input Impedance 6 Kohm DC_MAX Maximum Duty Cycle VDD=18V, RI=100Kohm, FB=3V, CS=0
75 %
Current Sen Input(Sen Pin) T_blanking Leading edge blanking time
RI = 100 Kohm 300 ns
Z SENSE _IN Input Impedance 40 Kohm
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T D _OC Over Current Detection and Control Delay VDD = 16V,
CS>V TH _OC, FB=3.3V
75 nSec V TH _OC Over-Current Threshold Voltage or Equivalent maximum input voltage at SENSE
FB=3.3V, RI=100 Kohm 0.70 0.75 0.80 V
Oscillator F OSC Normal Oscillation Frequency
RI = 100 Kohm 60 65 70 KHZ
∆f_Temp
Frequency Temperature Stability VDD = 16V, RI=100Kohm, T A -20o
C
to 100 o C
5 % ∆f_VDD
Frequency Voltage Stability VDD = 12-25V, RI=100Kohm
5 % RI_range Operating RI Range 50 100 150 Kohm V_RI_open RI open load voltage 2 V F osc _BM Burst Mode Ba Frequency VDD = 16V, RI = 100Kohm
22 KHZ
