SP6851
Green-Mode Power Switch
DESCRIPTION
The SP6851 is a low cost, low startup current, current
mode PWM controller with green-mode
power-saving operation. Built-in 650V MOSFET
provides simple design for adapter. The integrated
functions include the leading-edge blanking of the
current sensing, internal slope compensation. It
would provide the users a superior AC/DC power
application of higher efficiency, low external
component counts, and lower cost solution for
applications.
The SP6851 features more protections or functions
for the following characteristics :
※Add
OLP (Over Load Protection) function to
provide better protection performance for fault
conditions like short circuit or over load.
※Modify
the OVP (Over Voltage Protection)
mechanism from the cycle-by-cycle mode to the
hiccup mode.
SP6851 is available in DIP-8P package.
FEATURES
High-Voltage BiCMOS Process
Very Low Startup Current (<20µA)
Under Voltage Lockout (UVLO )
Current Mode Control
Non-audible-noise Green Mode Control
Current Limiting
OLP (Over Load Protection)
OVP (Over Voltage Protection) on Vcc Pin
Leading-Edge Blanking
Programmable Switching Frequency
Internal Slope Compensation
Green-Mode Control for Power Saving
APPLICATIONS
AC/DC Switching Power Adaptor
Battery Charger
PC 5V Standby Power.
Open-Frame Switching Power Supply
PIN CONFIGURATION
DIP-8P
Building in 650V MOSFET
PART MARKING
DIP-8P
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SP6851
Green-Mode Power Switch
TYPICAL APPLCATION CIRCUIT
TYPICAL APPLCATION CIRCUIT for HIGH EFFICIENCY SMPS
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SP6851
Green-Mode Power Switch
PIN DESCRIPTION
Pin
1
2
3
4
5
6
7
8
Symbol
Description
Source Power MOSFET Source
Current sense. This pin senses the voltage across a resistor, to control PWM output. This pin
CS
also provides current amplitude information for current-mode control.
GND Ground
RT
This current is used to charge an internal capacitor, to determine the switching frequency.
Voltage feedback. The pin provides the output voltage regulation signal, it provides feedback
COMP
to the internal PWM comparator, so that the PWM comparator can control the duty cycle.
VCC Supply Voltage in
Drain Power MOSFET Drain
Drain Power MOSFET Drain
BLOCK DIAGRAM
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SP6851
Green-Mode Power Switch
ORDERING INFORMATION
Part Number
SP6851D8TG
SP6851D8TGB
※
SP6851D8TG : Tube ; Pb – Free
Package
DIP-8P
DIP-8P
Part Marking
SP6851
SP6851
※
SP6851D8TGB : Tube ; Pb – Free ; Halogen – Free
ABSOULTE MAXIMUM RATINGS
(T
A
=25
℃
, unless otherwise specified.)
The following ratings designate persistent limits beyond which damage to the device may occur
.
Symbol
V
CC
V
COMP / RT / CS
V
DS
P
D
ESD
EAS
T
ope
T
J
T
STG
R
ӨJC
Parameter
DC Supply Voltage
COMP / RT / CS Voltage
MOSFET Breakdown Voltage
Power Dissipation @ T
A
=85
℃
(*)
Human Body Model
Machine Model
Single Pulse Avalanche Energy
Operating Ambient Temperature
Operating Junction Temperature Range
Storage Temperature Range
Thermal Resistance Junction – Case (*)
Value
36
-0.3 ~ 7.0
650
0.3
4
300
49
-40 ~ 85
-40 ~ 150
-40 ~ 150
95
Unit
V
V
V
W
KV
V
mJ
℃
℃
℃
℃
/W
(*) The power dissipation and thermal resistance are evaluated under copper board mounted with free air conditions.
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SP6851
Green-Mode Power Switch
ELECTRICAL CHARACTERISTICS
(T
A
=25
℃
, V
CC
=15V, unless otherwise specified.)
Symbol
Parameter
Supply Voltage ( Vcc Pin )
I
stt
Startup Current
I
op
Operating Current
Conditions
Min.
Typ.
10
2.7
2.4
Max.
20
4
Unit
uA
mA
mA
mA
V
V
V
mA
V
V
KHz
KHz
%
%
V
nS
MΩ
nS
%
%
V
uA
Ω
V
pF
V
COMP
= 0V
V
COMP
= 3V
Protection
(OLP, OVP)
tripped
1.0
9.0
15.0
26
10.0
16.0
27
1.25
6
2.35
11.0
17.0
29.5
2.2
UVLO
(off)
Min. Operating Voltage
UVLO
(on )
Start Threshold Voltage
OVP Level Over Voltage Protection
Voltage Feedback ( Comp Pin )
Isc
Short Circuit Current
Vop
Open Loop Voltage
V
TH(GM)
Green Mode Threshold VCOMP
Oscillator ( RT Pin )
F
OSC
Frequency
F
OSC(GM)
Green Mode Frequency
Fdt
Frequency Variation versus Temp. Deviation
Fdv
Frequency Variation versus V
CC
Deviation
Current Sensing ( CS Pin )
Vcs(off) Maximum Input Voltage
Leading Edge Blanking Time
T
LEDD
Zcs
Input impedance
T
PD
Delay to Output
MOSFET
DC
(Max)
Maximum Duty Cycle
DC
(Min)
Minimum Duty Cycle
V
DSS
Drain-Source Breakdown Voltage
I
DSS
Drain-Source Leakage Current
R
DS(ON)
On-State Resistance
V
SD
Forward On Voltage
Co
R
T
=100KΩ
Fs=65.0KHz
(-40°C ~105°C)
(V
CC
=11V-22V)
60.0
68.0
22
70.0
3
1
0.8
1
0.85
280
100
0.9
70
V
GS
=0V, I
D=
250uA
V
GS
=0V, V
DS=
550V
V
GS
=10V, I
D=
1A
V
GS
=0V, I
S
=1.4A
V
GS
=0V, V
DS
=25V,
f=1.0MHz
650
75
0
80
10
4.95
1.5
27
50
30
5.0
60
200
120
Output capacitance
Tr
Rising Time
Tf
Falling Time
OLP ( Over Load Protection )
OLP Trip Level
TL
OLP
TD
OLP
OLP Delay Time (note)
switching frequency and the shorter OLP delay time.
nS
nS
V
mS
Note: The OLP delay time is proportional to the period of switching cycle. So that, the lower RT value will set the higher
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