Critical Conduction Mode PFC Control IC
SSC2005S
General Description
SSC2005S is a Critical Conduction Mode (CRM)
control IC for power factor correction (PFC).
Since no input voltage sensing and no auxiliary
winding for inductor current detection are required, the
IC allows the realization of low standby power and the
low number of external components. The product
achieves high cost-performance and high efficiency PFC
converter system.
Package
SOIC8
FB
COMP
RT
RDLY
1
2
3
4
8
7
6
5
VCC
OUT
GND
CS
Features and Benefits
Inductor Current Detection
Not to scale
(No auxiliary winding required)
Low Standby Power
(No input voltage sensing required)
Minimum Off-time Limitation Function to restrict
the Rise of Operation Frequency
High Accuracy Overcurrent detection: −0.60 V ± 5 %
Protection Functions
Overcurrent Protection (OCP) ------- pulse-by-pulse
Overvoltage Protection (OVP) ------------ auto restart
FB Pin Undervoltage Protection (FB_UVP)
-------------------------------------------------- auto restart
Thermal Shutdown Protection with hysteresis (TSD)
-------------------------------------------------- auto restart
Electrical Characteristics
VCC pin Absolute Maximum Ratings, V
CC
= 28 V
OUT pin source current, I
OUT(SRC)
= −500 mA
OUT pin sink current, I
OUT(SNK)
= 1000 mA
Applications
PFC Circuit up to 200 W of Output Power such as:
AC/DC Power Supply
Digital appliances for large size LCD/PDP
Typical Application Circuit
D
BYP
BR1
VAC
D2
C1
R1
R3
R
CS
LINE
GND
R2
Q1
C2
L1
D1
V
OUT
television and so forth
OA equipment for Computer, Server, Monitor, and
so forth
Communication facilities
R4
DZ
CS
C5
5
U1
CS
RDLY
4
3
GND
NC
6
RT
COMP
R
DLY
C4
C
½
External power
supply
7
8
OUT
2
R
VS1
VCC
FB
C3
R
S
R
T
1
SSC2005S
C6
R
VS2
C
P
C
S
SSC2005S-DS Rev.1.3
Dec. 18, 2013
SANKEN ELECTRIC CO.,LTD.
1
SSC2005S
CONTENTS
General Description ------------------------------------------------------------------------ 1
1. Absolute Maximum Ratings --------------------------------------------------------- 3
2. Recommended Operating Conditions --------------------------------------------- 3
3. Electrical Characteristics ------------------------------------------------------------ 4
4. Functional Block Diagram ----------------------------------------------------------- 6
5. Pin Configuration Definitions ------------------------------------------------------- 6
6. Typical Application Circuit --------------------------------------------------------- 7
7. Package Outline ------------------------------------------------------------------------ 8
8. Marking Diagram --------------------------------------------------------------------- 8
9. Operational Description -------------------------------------------------------------- 9
9.1
Critical Conduction Mode: CRM ----------------------------------------- 9
9.2
Startup Operation ----------------------------------------------------------- 10
9.3
Restart Circuit --------------------------------------------------------------- 10
9.4
Maximum On-time setting------------------------------------------------- 10
9.5
Zero Current Detection ---------------------------------------------------- 11
9.6
Minimum Off-time Limit Function -------------------------------------- 11
9.7
Overvoltage Protection (OVP) Function ------------------------------- 12
9.8
FB pin Under Voltage Protection (FB_UVP) Function ------------- 12
9.9
Overcurrent Protection (OCP) Function ------------------------------- 12
10. Design Notes --------------------------------------------------------------------------- 13
10.1 External Components------------------------------------------------------- 13
10.2 PCB Trace Layout and Component Placement ----------------------- 16
11. Reference Design of Power Supply ----------------------------------------------- 17
OPERATING PRECAUTIONS -------------------------------------------------------- 19
IMPORTANT NOTES ------------------------------------------------------------------- 20
SSC2005S-DS Rev.1.3
Dec. 18, 2013
SANKEN ELECTRIC CO.,LTD.
2
SSC2005S
1.
Absolute Maximum Ratings
For additional details, refer to the datasheet.
The polarity value for current specifies a sink as “+”, and a source as “−”, referencing the IC.
Unless specifically noted Ta = 25 °C
Parameter
VCC Pin Voltage
OUT Pin Source Current
OUT Pin Sink Current
FB Pin Voltage
COMP Pin Current
RT Pin Current
RDLY Pin Current
CS Pin Voltage
Allowable Power Dissipation
Operating Ambient
Temperature
Storage Temperature
Junction Temperature
Symbol
V
CC
I
OUT(SRC)
I
OUT(SNK)
V
FB
I
COMP
I
RT
I
RDLY
V
CS
P
D
T
OP
T
stg
T
j
Conditions
Pins
8–6
7–6
7–6
1–6
2–6
3–6
4–6
5–6
−
−
−
−
Rating
28
−500
1000
−0.3 to 5
−200 to 200
−500 to 0
−500 to 0
−5 to 0.3
0.5
−40 to 110
−40 to 150
150
Unit
V
mA
mA
V
µA
µA
µA
V
W
°C
°C
°C
Notes
2.
Recommended Operating Conditions
Recommended operating conditions means the operation conditions maintained normal function shown in
electrical characteristics.
Parameter
Symbol
Pins
Min.
Max.
Unit
Notes
VCC Pin Voltage in Operation
RT Pin Resistance
RDLY Pin Resistance
Output Voltage – Input Voltage
V
CC(OP)
R
RT
R
RDLY
V
OUT
− V
IN
8–6
3–6
4–6
−
14
15
15
20
26
47
47
−
V
kΩ
kΩ
V
SSC2005S-DS Rev.1.3
Dec. 18, 2013
SANKEN ELECTRIC CO.,LTD.
3
SSC2005S
3.
Electrical Characteristics
For additional details, refer to the datasheet.
The polarity value for current specifies a sink as “+”,
and
a source as “−”, referencing the IC.
Unless specifically noted, Ta = 25 °C, V
CC
= 14 V, V
CS
= 0.1 V
Parameter
Power Supply Operation
Operation Start Voltage
Operation Stop Voltage
Operation Voltage Hysteresis
Circuit Current in Operation
Circuit Current in
Non-Operation
Oscillation Operation
Maximum On-Time
Minimum Off-Time
RDLY Pin Voltage
RT Pin Voltage
Feedback Control Voltage
Feedback Line Regulation
FB Pin Bias Current
Error Amplifier
Transconductance Gain
COMP Pin Sink Current
COMP Pin Source Current
Zero Duty COMP Voltage
Restart Time
Drive Output
Output Voltage (High)
Output Voltage (low)
Output Rise Time
Output Fall Time
(2)
(2)
Symbol
Conditions
Pins
8–6
8–6
8–6
8–6
Min.
Typ.
Max.
Unit
V
CC(ON)
V
CC(OFF)
V
CC(HYS)
I
CC(ON)
I
CC(OFF)
V
CC
= 9.5 V
10.5
8.2
1.4
2.0
40
12.0
9.5
2.5
3.1
80
13.5
11.0
3.1
4.4
160
V
V
V
mA
µA
8–6
t
ON(MAX)
t
OFF(MIN)
V
RDLY
V
RT
V
FB
V
FB(LR)
I
FB
gm
I
COMP(SNK)
I
COMP(SRC)
V
COMP(ZD)
t
RS
V
FB
= 1.5 V
R
DLY
= 22 kΩ
R
DLY
= 22 kΩ
7–6
7–6
4–6
3–6
1–6
1–6
1–6
1–6
2–6
2–6
2–6
2–6
−
15
1.8
1.3
1.3
2.46
−8
−3.2
60
18
−72
0.50
30
23
2.5
1.5
1.5
2.50
1
−2.0
103
40
−40
0.65
50
33
3.2
1.7
1.7
2.54
12
−1.0
150
72
−18
0.90
80
µs
µs
V
V
V
mV
µA
µS
µA
µA
V
µs
V
OH
V
OL
t
r
t
f
I
OUT
= –100 mA
I
OUT
= 200 mA
C
OUT
= 1000 pF
C
OUT
= 1000 pF
7–6
7–6
7–6
7–6
10.0
0.40
−
−
12.0
0.75
60
20
13.5
1.25
120
70
V
V
ns
ns
Zero Current Detection and Overcurrent Protection Function
Zero Current Detection
V
CS(ZCD)
Threshold Voltage
Zero Current Detection Delay
(1)
t
DLY(ZCD)
R
DLY
= 22 kΩ
Time
Overcurrent Protection
V
CS(OCP)
Threshold Voltage
Overcurrent Protection Delay
(1)
t
DLY(OCP)
Time
CS Pin Source Current
I
CS
(1)
(2)
5–6
5–6
5–6
5–6
5–6
−16
1.00
−0.63
100
−110
−10
1.35
−0.60
250
−75
−4
1.70
−0.57
400
−40
mV
µs
V
ns
µA
Design assurance item
Shown in Figure 3-1
SSC2005S-DS Rev.1.3
Dec. 18, 2013
SANKEN ELECTRIC CO.,LTD.
4
SSC2005S
Parameter
FB Pin Protection Function
Overvoltage Protection
Threshold Voltage
Overvoltage Protection
Hysteresis
Undervoltage Protection
Threshold Voltage
Undervoltage Protection
Hysteresis
Thermal Shutdown Protection
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
Thermal Resistance
Junction to Ambient
Resistance
(1)
(1)
(1)
Symbol
Conditions
Pins
Min.
1.075
×V
FB
55
200
80
Typ.
1.090
×V
FB
90
300
120
Max.
1.105
×V
FB
125
400
160
Unit
V
OVP
V
OVP(HYS)
V
UVP
V
UVP(HYS)
1–6
1–6
1–6
1–6
V
mV
mV
mV
T
j(TSD)
T
j(TSDHYS)
–
–
135
–
150
10
–
–
°C
°C
(1)
θ
j-A
–
–
–
180
°C/W
Design assurance item
90%
V
OUT
tr
tf
10%
Figure 3-1 Switching time
SSC2005S-DS Rev.1.3
Dec. 18, 2013
SANKEN ELECTRIC CO.,LTD.
5
