MC3265N6

CYStech Electronics Corp.
Spec. No. : C595N6
Issued Date : 2012.02.23
Revised Date :
Page No. : 1/12
Current Mode PWM Controller
MC3265N6
Description
MC3265 is a highly integrated current mode PWM control IC optimized for high performance low standby
power offline flyback converter applications.
To improve the efficiency, MC3265 works at QR (Quasi-Resonant) mode or fixed frequency(52KHz) while
the loading is high and the line voltage is high or low.
At normal loading, MC3265 works at QR mode and the frequency is limited to 95KHz.
To meet the international power conservation requirements, optimized green mode is integrated to improve
the efficiency at light or no load conditions with no audible noise.
Slope compensation is integrated to ensure the stability at high load. Lead edge blanking is integrated to
prevent the false trigger at the transition of the switch. Soft switching control at the gate drive can improve
the EMI performance of the power supply. The Gate-drive output is clamped at 16V to protect the power
MOS.
Features
●Frequency jitter function to improve EMI performance of power supply
●No-audible-noise green mode Control
● Multi operation mode: QR, fixed-frequency CCM and green mode.
● Internal Slope Compensation
● Low VDD Startup Current and Low Operating Current
● Leading Edge Blanking
● UVLO
● Gate Max Output Voltage Clamp at 16V
● Overload Protection (OLP).
● Over temperature Protection (OTP).
● Line Compensation Over Current Protection (OCP)
Applications
Offline AC/DC flyback converter for
● Battery Charger
● Power Adaptor
● Set-Top Box Power Supplies
● Open-frame SMPS
● PC 5V Standby Power
● TV Power Supplies Standby
MC3265N6
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C595N6
Issued Date : 2012.02.23
Revised Date :
Page No. : 2/12
Ordering Information
Device
Package
Shipping
MC3265N6
SOT-23-6L
(Pb-free lead plating)
3000 pcs / tape & reel
Typical Application Circuit
LM8631
Pin Configuration
MC3265N6
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C595N6
Issued Date : 2012.02.23
Revised Date :
Page No. : 3/12
Pin Assignment
Pin Name
Pin Number
Pin Function
GND
1
FB
2
DEM
SENSE
VDD
GATE
3
4
5
6
Ground
Feedback input pin. The PWM duty cycle is determined by voltage level into
this pin and the current-sense signal at Pin 6.
The ‘valley’ and output over voltage detect pin.
Current sense input pin. Connected to MOSFET current sensing resistor node.
Chip DC power supply pin.
Totem-pole gate drive output for the power MOSFET.
Function Block Diagram
Absolute Maximum Ratings
Parameter
VDD to GND
VDD clamped current
VDD clamped voltage
VFB, VSENSE and VDEM to GND
Maximum Junction Temperature (Tj MAX)
Storage Temperature Range
Value
29
10
29
-0.3~+7
150
-55 ~ +150
Unit
V
mA
V
V
°C
°C
Note：Stresses beyond those listed under “Absolute Maximum Ratings" may cause permanent damage to the device.
MC3265N6
CYStek Product Specification
Spec. No. : C595N6
Issued Date : 2012.02.23
Revised Date :
Page No. : 4/12
CYStech Electronics Corp.
Recommended Operating Conditions
● Supply
Voltage, VDD………………………………………………………………………...10V to 30V
● Operating Temperature Range……………………………………………………………-20°C to 85°C
● Thermal Resistance ,junction to ambient (Rthja @25℃)…………………………………….250°C/W
ESD In formations
● Human Body Mode------------------------------------------------------------------------------------- 2000V
● Machine Mode------------------------------------------------------------------------------------------ 200V
Electrical Characteristics (TA = 25°C, VDD=16V if not otherwise noted)
(TA = 25°C, VDD=16V if not otherwise noted)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Units
3
20
uA
SUPPLY SECTION
Vdd=12V, measure current into VDD
pin
VDD=16V,VFB=3V
Chip start up current via VDD pin
I_set
Operation current
I_op
VDD Off(Turn-off threshold)
UVLO_L
7.5
8.5
9.5
V
VDD on(Turn-on threshold)
UVLO_H
14.5
15.5
16.5
V
25
28
28.5
V
28.5
29
30
V
VDD OVP(Over Voltage Protection )
VZ(VDD clamp voltage)
VDD_CLP
Iz(Idd)=10mA
PWM input gain
A_PWM
ΔVFB/ΔVCS
VFB open loop voltage
VFB_O
1.4
mA
FEEDBACK SECTION
Short FB pin to gnd and measure
current
3.5
V/V
5.3
V
1.1
mA
FB pin short circuit current
VFB_S
Burst mode on threshold
V_BM_on
0.9
V
Burst mode off threshold
V_BM_off
0.8
V
Power limiting FB threshold
VFB_th_P
4.4
V
Power limiting delay time
T_PL_D
80
ms
Input impedance
R_FB
5
KΩ
Soft start time
T_soft start
4
ms
Burst mode switching frequency
F_burst
Max frequency in QR mode
Fmax_QR
80
95
110
KHz
Min frequency in QR mode
Fmin_QR
47
52
57
KHz
Max on time
Ton_max
10
12.5
15
us
Max off time
Toff_max
45
60
80
us
400
nS
TIMER
22
KHz
CURRENT SENSE SECTION
Leading edge blanking time
T_blank
300
Sense pin input impedance
R_sense
40
Over current threshold voltage at
zero duty cycle
VTH_OC_0
MC3265N6
FB=3.3V
0.42
0.45
kΩ
0.48
V
CYStek Product Specification
Spec. No. : C595N6
Issued Date : 2012.02.23
Revised Date :
Page No. : 5/12
CYStech Electronics Corp.
Over current threshold voltage at
max. switching on time
VTH_OC_1
FB=3.3V
0.8
Over current protect delay
T_OC_D
CS>VTH_OC, FB=3.3V,CL=1nf
@Gate
75
Output low level(Turn-off)
VOL
Io=20mA
Output high level(Turn-on)
VOH
Io=20mA
Output voltage clamped level
VO_clamp
16
V
Output rising time (10%~90%)
Tr
Cl=1nf
220
nS
Output falling time(90%~10%)
Tf
Cl=1nf
70
ns
0.85
V
nS
GATE OUTPUT
0.8
10V
V
V
DEM Pin
Dem comparator threshold voltage
Vth_dem
75
mV
Suppression time @ the ringing
stage
T_supp
2.5
us
Timeout after last dem. transistion
T_out_dem
5
us
Dem. Propagation delay
T_dem_d
250
ns
Output OVP trigger point
Vth_OVP
3,75
V
Output OVP delay time
T_OVP_de
4
Cycle
OTP
Thermal shutdown temperature
MC3265N6
Tem_off
145
150
160
℃
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C595N6
Issued Date : 2012.02.23
Revised Date :
Page No. : 6/12
Characterization Plots
TA = 25°C, VDD=16V if not otherwise noted
Start Current Vs VDD Voltage
UVLO Voltage& Operation Current
Operation Current VS Load
UVLO (On) Voltage VS Temp
UVLO (Off) Voltage VS Temp
MC3265N6
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C595N6
Issued Date : 2012.02.23
Revised Date :
Page No. : 7/12
OPERATION DESCRIPTION
Over-view description
The MC3265 includes all necessary function to build an easy and cost effective solution for low power supplies to
meet the international power conservation requirements.
Start-up current
Startup current of MC3265 is designed to be very low so that VDD could be charged up above UVLO (exit) threshold
level and device starts up quickly. Also a large value startup resistor can be used to minimize the power loss.
Green Mode Operation （Patent）
At light load or no load condition, the switch loss become the major loss of the power supply, to reduce the power
wasted in light and no load condition, based on a special designed voltage controlled oscillator, green mode
operation of the power supply can be achieved by using MC3265. The controller will judge the load condition base on
the voltage of FB pin. In light load the FB voltage will decrease, when VFB is lower than a set threshold voltage, a FB
depending time (TR2) will be generated by the oscillator and decrease the operating frequency of the power supply,
the minimum frequency is set about 22kHZ. The function block and the working waveform can be depicted as below:
When VFB decrease further, the power supply will enter into burst mode operation to decrease the power
consumed at no load condition. Besides there is no audible noise in any load condition.
While MC3265 works in CCM mode, slope compensation and frequency shuffling is activated. The sensed voltage
across the sense resistor is used for pwm control, and pulse by pulse current limit, Built-in slope compensation circuit
adds a voltage
MC3265N6
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C595N6
Issued Date : 2012.02.23
Revised Date :
Page No. : 8/12
Multi-mode Operation
MC3265 is a multi-mode QR-PWM controller. The controller changes the mode of operation according to
line voltage and load conditions.
At full load and low line input condition, the IC operates in fix frequency(52kHz) CCM mode; At full load
and high line input condition, the IC operates in QR mode. Thus, high power conversion efficiency can be
achieved in the universal input range when system is at full loading conditions.
At normal loading conditions, the system operates in QR mode (frequency is clamped between 52kHz to
95kHz).
At light load conditions, the system operates in Green mode for high power conversion.
Built-in Slope Compensation and Frequency Shuffling
While MC3265 works in CCM mode, slope compensation and frequency shuffling is activated. The sensed
voltage across the sense resistor is used for pwm control, and pulse by pulse current limit, Built-in slope
compensation circuit adds a voltage ramp onto the current sense input voltage. This greatly improves the
close loop stability and prevents the sub-harmonic oscillation of peak current mode pwm control scheme.
To improve the EMI performance, the frequency of CCM mode is shuffling to 52kHz ± 5%
Line Slope Compensation
Adjusting the RSENSE can set the Max output power of the power supple mode. The current flowing by the
power MOSFET has an extra value due to the system delay T that the current detected from the sense pin to
power MOSFET cut off in the MC3265. To guarantee the output power is a constant for universal input AC
voltage, there is a positive ramp signal to compensate the system delay T and the line input. At lower
line-input voltage the higher OCP threshold will bring constant power OCP as below.
Demagnetization(Dem.) Detection
The transformer core demagnetization is detected by monitoring the voltage waveform on the auxiliary
winding through DEM pin. While the voltage on DEM pin is lower than 75mV, Dem. Detection will
generate a ‘valley’ signal and MC3265 make the GATE on depending the condition of FB and SENSE pins.
To avoid the ringing of the MOSFET’s drain voltage misleading this function, T_supp is added. Each time
the GATE is off, T_supp starts to count. During T_supp, GATE remains low and can’t be turn to high.
MC3265N6
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C595N6
Issued Date : 2012.02.23
Revised Date :
Page No. : 9/12
Leading Edge Blanking
Each time when the power MOSFET is switched on, a turn-on spike will inevitably occur on the
sense-resistor. To avoid premature termination of the switching pulse, a 300 nsec leading-edge blanking
time is built in. Conventional RC filtering can therefore be omitted. During this blanking period, the
current-limit comparator is disabled and it cannot switch off the gate driver.
Gate Driver
The output stage of MC3265 is a fast totem pole gate driver. Cross conduction has been avoided to
minimize heat dissipation, increases efficiency and enhances reliability. The output driver is clamped by an
internal 16V Zener diode in order to protect power MOSFET transistors against undesirable gate over
voltage. A soft driving waveform is implemented to minimize EMI.
Protect Functions
To increase the reliability of power supply system many protection functions is integrated in this controller,
including Cycle-by-Cycle current limiting (OCP), Over Load Protection (OLP), Over Temperature
Protection(OTP), Output Over Voltage Protection (OVP) and over voltage clamp, Under Voltage Lockout
on VDD (UVLO). At overload condition when FB input voltage exceeds power limit threshold value for
more than TD_PL (power limit debounce time), the controller reacts to shut down the output power
MOSFET. Device restarts when VDD voltage drops below UVLO limit. VDD is supplied by transformer
auxiliary winding output. It is clamped when VDD is higher than threshold value. The power MOSFET is
shut down when VDD drops below UVLO limit and device enters power on start-up sequence thereafter.
Pin floating protection for CS, FB, DEM is also added. While one of this happens, the GATE is turned off.
MC3265N6
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C595N6
Issued Date : 2012.02.23
Revised Date :
Page No. : 10/12
Reel Dimension
Carrier Tape Dimension
MC3265N6
CYStek Product Specification
CYStech Electronics Corp.
Spec. No. : C595N6
Issued Date : 2012.02.23
Revised Date :
Page No. : 11/12
Recommended wave soldering condition
Product
Pb-free devices
Peak Temperature
260 +0/-5 °C
Soldering Time
5 +1/-1 seconds
Recommended temperature profile for IR reflow
Profile feature
Average ramp-up rate
(Tsmax to Tp)
Preheat
−Temperature Min(TS min)
−Temperature Max(TS max)
−Time(ts min to ts max)
Time maintained above:
−Temperature (TL)
− Time (tL)
Peak Temperature(TP)
Time within 5°C of actual peak
temperature(tp)
Ramp down rate
Time 25 °C to peak temperature
Sn-Pb eutectic Assembly
Pb-free Assembly
3°C/second max.
3°C/second max.
100°C
150°C
60-120 seconds
150°C
200°C
60-180 seconds
183°C
60-150 seconds
240 +0/-5 °C
217°C
60-150 seconds
260 +0/-5 °C
10-30 seconds
20-40 seconds
6°C/second max.
6 minutes max.
6°C/second max.
8 minutes max.
Note : All temperatures refer to topside of the package, measured on the package body surface.
MC3265N6
CYStek Product Specification
Spec. No. : C595N6
Issued Date : 2012.02.23
Revised Date :
Page No. : 12/12
CYStech Electronics Corp.
SOT-23-6L Dimension
A
D
Marking:
d1
d2
6
5
4
Style:
Pin 1. GND
Pin 2. FB
Pin 3. DEM
Pin 4. SENSE
Pin 5. VDD
Pin 6. GATE
B C
○
1
2
3
65ABC
Device Name
Date Code
E
6-Lead SOT-23-6L Plastic
Surface Mounted Package
CYStek Package Code: N6
I
F
L
H
J
G
Inches
Min.
Max.
0.1063
0.1220
0.1024
0.1181
0.0551
0.0709
0.0748 REF
0.0374 REF
0.0374 REF
0.0118
0.0217
DIM
A
B
C
D
d1
d2
E
Millimeters
Min.
Max.
2.70
3.10
2.60
3.00
1.40
1.80
1.90 REF
0.95 REF
0.95 REF
0.30
0.55
K
DIM
F
G
H
I
J
K
L
Inches
Min.
Max.
0.0472 REF
0
0.0059
0.0086
0.0047 REF
0.0146 REF
0.0236 REF
0°
10°
Millimeters
Min.
Max.
1.20 REF
0
0.15
0.22
0.12 REF
0.37 REF
0.60 REF
0°
10°
Notes : 1.Controlling dimension : millimeters.
2.Maximum lead thickness includes lead finish thickness, and minimum lead thickness is the minimum thickness of base material.
3.If there is any question with packing specification or packing method, please contact your local CYStek sales office.
Material :
• Mold Compound : Epoxy resin family, flammability solid burning class:UL94V-0
Important Notice:
• All rights are reserved. Reproduction in whole or in part is prohibited without the prior written approval of CYStek.
• CYStek reserves the right to make changes to its products without notice.
• CYStek semiconductor products are not warranted to be suitable for use in Life-Support Applications, or systems.
• CYStek assumes no liability for any consequence of customer product design, infringement of patents, or application assistance.
MC3265N6
CYStek Product Specification