PR622X—PR6221/6224/6228/6229

Green-Power Current Mode PWM Power Switch

Features
 Build in Soft Start: 4mS Current
 Advanced Hiccup Mode Control For  Leading Edge Blanking on Current
Improved Efficiency and Minimum Sense Input
Standby power Design  Under-Voltage Lockout (UVLO) with
 Audio Noise Free Operation Hysteresis
 Fixed Operating Frequency :50KHz  Overload Protection(OLP)
 Build in Slope Compensation  Over-Voltage Protection(OVP)
 Low Startup Current and Low Operating  Auto- recovery Mode

Applications
 Battery Charger  Set-Top Box (STB) Power
 Digital Cameras and camcorder  Auxiliary Power Supply for PC and
Adaptor Server
 VCR, SVR, DVD & DVCD Player SMPS  Open-frame SMPS

General Description
PR622X combines a dedicated current VDD over voltage clamp and under voltage
mode PWM controller with a high voltage lockout (UVLO). Excellent EMI performance
power MOSFET. It is optimized for high is achieved with frequency jitter technique
performance, low standby power, and cost together with soft switching control at the
effective off-line flyback converter totem pole gate drive output.
applications in sub 24W range. PR622X is offered in Lead-free DIP-8L &
PR622X offers complete protection SOP-8L package.
coverage with automatic self-recovery
feature including Cycle-by-Cycle current
limiting (OCP), over load protection (OLP),

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PR622X Green-Power Current Mode PWM Power Switch

Block Diagram

VDDG
1 Drain
5/6
Current
Reference Soft Power
Driver MOSFET

R Q
Soft-start
S

hiccup
OSC mode OCP
Internal
VDD supply
2 SENSE
Slope
compensation LEB 4
5V

Vth

UVLO
POR
5.7V

hiccup PWM
VDD mode Compartor
clamper
FB
50ms OLP 3

7/8
GND

Pin Assignment （DIP-8L & SOP-8L）

VDDG 1 8 GND

VDD 2 7 GND
PR622X
FB 3 6 Drain

SENSE 4 5 Drain

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Typical Application

~
AC
EMI
FILTER

VDDG GND

VDD GND TL431

FB Drain

SENSE Drain

PR622X

Pin Descriptions
Pin Name Description
GND Ground
Feedback input pin. The PWM duty cycle is determined by voltage level into
FB
this pin and the current-sense signal at Pin 4.
VDD-G Internal Gate Driver Power Supply
SENSE Current sense input
VDD IC DC power supply Input
HV MOSFET Drain Pin. The Drain pin is connected to the primary lead of the
Drain
transformer.

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Absolute Maximum Ratings

Parameter Value
Drain Voltage (off state) -0.3V to 600V
VDD Voltage -0.3V to 30V
VDD-G Input Voltage -0.3V to 30V
VDD Clamp Continuous Current 10 mA
FB Input Voltage -0.3V to 7V
Sense Input Voltage -0.3V to 7V
Min/Max Operating junction Temperature TJ -20℃ to 150℃
Min/Max Storage Temperature Tstg -55℃ to 160℃
Lead Temperature (Soldering, 10secs) 260℃
Note: Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the
device. Exposure to absolute maximum-rated conditions for extended periods may affect device reliability.

Output Power Table

230VAC 15% 85-265VAC
Package 1 1
Open Frame Open Frame
PR6221T DIP-8L 10W 8.5W
PR6224S SOP-8L 10W 8W
PR6224T DIP-8L 15W 12W
PR6228T DIP-8L 21W 18W
PR6229T DIP-8L 28W 24W
Notes:
1. Maximum practical continuous power in an open frame design with sufficient drain pattern as a heat sink,
at 50℃ ambient.

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PR622X Green-Power Current Mode PWM Power Switch

Electrical Characteristics
(Ta=25°C unless otherwise noted, VDD = 16V)

Symbol Parameter Test Conditions Min Typ Max Unit

Supply Voltage (VDD)

VDD=14.1V, Measure

Istartup VDD Start up Current Leakage current into 3 20 uA

VDD

I_VDD
Operation Current VFB=3V 2 mA
(Operation)

VDD Under Voltage Lockout

UVLO(ON) 8.5 9 9.5 V
Enter

VDD Under Voltage Lockout

UVLO(OFF) 14.2 14.8 16 V
Exit(Recovery)

CS=0V, FB=3V
Over voltage protection
OVP(ON) Ramp up VDD until 27.0 28.5 30.0 V
voltage
gate clock is off

VDD_Clamp VDD Zener clamp Voltage IDD=10mA 30 V

Feedback Input Section(FB pin)

VFB_Open VFB Open Loop Voltage 5.4 5.6 6.0 V

Short FB pin to GND and

IFB_Short FB pin short circuit current 1.55 mA
measure current

Zero Duty Cycle FB

VTH_0D 0.8 V
Threshold Voltage

Power Limiting FB Threshold

VTH_PL 3.7 V
Voltage

Power Limiting Debounce

TD_PL 50 mS
Time

ZFB_IN Input Impedance 4 KΩ

Current Sense Input(Sense Pin)

Soft start time 4 ms

T_blanking Leading edge blanking time 300 ns

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PR622X Green-Power Current Mode PWM Power Switch

ZSENSE_IN Input Impedance 40 KΩ

From Over Current

Over Current Detection and
TD_OC Occurs till the Gate drive 120 nS
Control Delay
output start to turn off

Internal Current Limiting

VTH_OC FB=3.3V 0.76 0.8 0.82 V
Threshold Voltage

Oscillator
Fosc Normal Oscillation Frequency 45 50 55 KHz

Frequency Temperature
△ f_Temp 5 %
Stability

△ f_VDD Frequency Voltage Stability 5 %

D_max Maximum duty cycle FB=3.3V, CS=0V 70 80 90 %

F_Hiccup Hiccup Mode Base Frequency 22 KHz

Power MOSFET Section

MOSFET Drain Source
BVdss VGS=0V, IDS=250uA 600 V
Breakdown Voltage

PR6221T 8.0 9.5 Ω

PR6224S 5.0 5.8 Ω

Static Drain to Source On VGS=10V,
RDS(on) PR6224T 5.0 5.8 Ω
Resistance IDS=1A
PR6228T 3.0 3.6 Ω

PR6229T 2.0 2.5 Ω

Frequency jitting
Frequency Modulation range
△ f_SOC -4 4 %
/Base frequency

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Operation Description
The PR622X is a low power off-line SMPS Oscillator Normal Operation
Switcher optimized for off-line flyback The normal switching frequency of PR622X
converter applications in sub 24W power is internally fixed at 50 KHz. No external
range. The Hiccup mode control greatly frequency setting components are required
reduces the standby power consumption
for PCB design simplification.
and helps the design easily to meet the
international power conservation
Frequency jitting for EMI improvement
requirements.
The frequency jitter (switching frequency
Startup Current and Start up Control modulation) is implemented in PR622X. The
oscillation frequency is modulated so that
Startup current of PR622X is designed to be
the tone energy is spread out. The spread
very low so that VDD could be charged up
spectrum minimizes the conduction band
above UVLO threshold level and device
EMI and therefore eases the system design.
starts up quickly. A large value startup
resistor can therefore be used to minimize
Advanced Hiccup Mode Operation
the power loss yet achieve a reliable startup
in application. For AC/DC adaptor with At light load or zero load condition, most of
universal input range design, a 2 MΩ, 1/8 W the power dissipation in a switching mode
startup resistor could be used together with power supply is from switching loss on the
a VDD capacitor to provide a fast startup MOSFET, the core loss of the transformer
and yet low power dissipation design and the loss on the snubber circuit. The
solution. magnitude of power loss is in proportion to
the switching frequency. Lower switching
Operation current frequency leads to the reduction on the
power loss and thus conserves the energy.
The Operation current of PR622X is lower
The switching frequency is internally
than 2 mA. Good efficiency is achieved with
adjusted at no load or light load condition.
PR622X low operating current together with
The switch frequency reduces at light/no
the „Advanced Hiccup mode‟ control
load condition to improve the conversion
features.
efficiency. At light load or no load condition,
the FB input drops below Hiccup mode
Soft Start
threshold level and device enters Hiccup
PR622X features an internal 4 ms soft start Mode control. The Gate drive output
to soften the electrical stress occurring in switches only when VDD voltage drops
the power supply during startup. It is below a preset level and FB input is active to
activated during the power on sequence. As output an on state to minimize the switching
soon as VDD reaches UVLO(OFF), the loss and reduce the standby power
peak current is gradually increased from consumption to the greatest extend.
nearly zero to the maximum level. Every The switching frequency control also
restart up is followed by a soft start. eliminates the audio noise at any loading
conditions.

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PR622X Green-Power Current Mode PWM Power Switch

Current Sensing and Leading Edge In addition to the gate drive control scheme
Blanking mentioned, the gate drive strength can also
be adjusted externally by a resistor
Cycle-by-Cycle current limiting is offered in
connected between VDD and VDDG, the
PR622X current mode PWM control. The
falling edge of the Drain output can be well
switch current is detected by sense resistor
controlled. It provides great flexibility for
into the sense pin. An internal leading edge
system EMI design.
blank circuit chops off the sensed voltage
spike at initial internal power MOSFET on
Protection Controls
state due to snubber diode reverse recovery
and surge gate current of internal power Good power supply system reliability is
MOSFET so that the external RC filtering on achieved with its rich protection features
sense input is no longer needed. The including Cycle-by-Cycle current limiting
current limiting comparator is disabled and (OCP); Over load Protection (OLP); Under
cannot turn off the internal power MOSFET Voltage Lockout on VDD (UVLO); Over
during the blanking period. The PWM duty voltage protection (OVP) and VDD clamp
cycle is determined by the current sense function.
input voltage and the FB input voltage. The OCP is line voltage compensated to
achieve constant output power limit over the
Internal Slope Compensation universal input voltage range.
At overload condition when FB input voltage
Built-in slope compensation circuit adds
exceeds power limit threshold value for
voltage ramp onto the current sense input
more than TD_PL, control circuit reacts to
voltage for PWM generation. This greatly
shut down the switcher. Switcher restarts
improves the close loop stability at CCM and
when VDD voltage drops below UVLO limit.
prevents the sub-harmonic oscillation and
VDD is supplied by transformer auxiliary
thus reduces the output ripple voltage.
winding output. When VDD ramp up to OVP
threshold voltage (28.5V), the output of
Drive
PR622X will be shut down, when VDD drops
The internal power MOSFET in PR622X is
below UVLO(ON) limit and Switcher enters
driven by a dedicated gate driver for power
power on start-up sequence thereafter.
switch control. Too weak the gate drive
When VDD is higher than VDD clamp
strength results in higher conduction and
threshold voltage, the internal VDD clamp
switch loss of MOSFET while too strong
circuitry will clamp VDD to 30V, and the
gate drive results the compromise of EMI.
output of PR622X is shut down also.
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.

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PR622X Green-Power Current Mode PWM Power Switch

Characterization Plots
The characteristic graphs are normalized at TA=25℃.

UVLO(ON)(V) VS Temperature(C)
UVLO(OFF)(V) VS Temperature(C)
10.00
15.9
15.8

UVLO(OFF)(V)
9.80
UVLO(ON)(V)

15.7
9.60
15.6
9.40
15.5
9.20 15.4
9.00 15.3
-40 -10 20 50 80 110 -40 -10 20 50 80 110
Temperature(C)
Temperature(C)
Temperature&UVLO(ON) Temperature&UVLO(OFF)

Vth_OC(V) VS Duty(%)
1.1

1.0
Vth_OC(V)

0.9

0.8

0.7
10 15 30 45 60 80
Duty(%)
Vth_OC&Duty

Istartup(uA) VS Temperature(C) Fosc(KHz) VS Temperature(C)

4.0 52

51
Istartup(uA)

3.5
Fosc(KHz)

3.0 50

2.5 49

2.0 48
-40 -10 20 50 80 110 -40 -10 20 50 80 110
Temperature(C) Temperature(C)
Istartup&Temperature Fosc&Temperature

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Package Dimensions
DIP-8L

Dimensions
MILLIMETER
SYMBOL
MIN. NOM MAX.
A 3.60 3.80 4.00
A1 0.51 --- ---
A2 3.00 3.30 3.40
A3 1.55 1.60 1.65
b 0.44 --- 0.53
b1 0.43 0.46 0.48
B1 1.52BSC
c 0.24 --- 0.32
c1 0.23 0.25 0.27
D 9.05 9.25 9.45
E1 6.15 6.35 6.55
e 2.54BSC
eA 7.62BSC
eB 7.80 --- 9.20
eC 0 --- 0.84
L 3.00 --- ---

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SOP-8L

Dimensions
Millimeter
Symbol
Min. Nom. Max.
A --- --- 1.75
A1 0.10 --- 0.225
A2 1.30 1.40 1.50
A3 0.60 0.65 0.70
b 0.39 --- 0.48
b1 0.38 0.41 0.43
c 0.21 --- 0.26
c1 0.19 0.20 0.21
D 4.70 4.90 5.10
E 5.80 6.00 6.20
E1 3.70 3.90 4.10
e 1.27BSC
h 0.25 --- 0.50
L 0.50 --- 0.80
L1 1.05BSC
θ˚ 0˚ --- 8˚

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