NCP1207
PWM Current−Mode
Controller for Free Running
Quasi−Resonant Operation
The NCP1207 combines a true current mode modulator and a
demagnetization detector to ensure full borderline/critical
Conduction Mode in any load/line conditions and minimum drain
voltage switching (Quasi−Resonant operation). Due to its inherent skip
cycle capability, the controller enters burst mode as soon as the power
demand falls below a predetermined level. As this happens at low peak
current, no audible noise can be heard. An internal 8.0
ms
timer prevents
the free−run frequency to exceed 100 kHz (therefore below the 150 kHz
CISPR−22 EMI starting limit), while the skip adjustment capability lets
the user select the frequency at which the burst foldback takes place.
The Dynamic Self−Supply (DSS) drastically simplifies the
transformer design in avoiding the use of an auxiliary winding to supply
the NCP1207. This feature is particularly useful in applications where
the output voltage varies during operation (e.g. battery chargers). Due to
its high−voltage technology, the IC is directly connected to the
high−voltage DC rail. As a result, the short−circuit trip point is not
dependent upon any V
CC
auxiliary level.
The transformer core reset detection is done through an auxiliary
winding which, brought via a dedicated pin, also enables fast
Overvoltage Protection (OVP). Once an OVP has been detected, the IC
permanently latches off.
Finally, the continuous feedback signal monitoring implemented with
an Overcurrent Fault Protection (OCP) circuitry makes the final design
rugged and reliable.
Features
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MARKING
DIAGRAMS
8
8
1
SOIC−8
D1, D2 SUFFIX
CASE 751
1
8
PDIP−8
N SUFFIX
CASE 626
1
1
1207/P
A
WL, L
YY, Y
WW, W
= Device Code
= Assembly Location
= Wafer Lot
= Year
= Work Week
1207P
AWL
YYWW
1207
ALYW
8
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Pb−Free Packages are Available*
Free−Running Borderline/Critical Mode Quasi−Resonant Operation
Current−Mode with Adjustable Skip−Cycle Capability
No Auxiliary Winding V
CC
Operation
Auto−Recovery Overcurrent Protection
Latching Overvoltage Protection
External Latch Triggering, e.g. Via Overtemperature Signal
500 mA Peak Current Source/Sink Capability
Internal 1.0 ms Soft−Start
Internal 8.0
ms
Minimum T
OFF
Adjustable Skip Level
Internal Temperature Shutdown
Direct Optocoupler Connection
SPICE Models Available for TRANsient Analysis
AC−DC Adapters for Notebooks, etc.
Offline Battery Chargers
Consumer Electronics (DVD Players, Set−Top Boxes, TVs, etc.)
Auxiliary Power Supplies (USB, Appliances, TVs, etc.)
PIN CONNECTIONS
DMG
FB
CS
GND
1
2
3
4
(Top View)
8
7
6
5
HV
NC
V
CC
Drv
ORDERING INFORMATION
Device
NCP1207DR2
NCP1207DR2G
NCP1207P
NCP1207PG
Package
SOIC−8
SOIC−8
(Pb−Free)
PDIP−8
PDIP−8
(Pb−Free)
Shipping
†
2500/Tape & Reel
2500/Tape & Reel
50 Units/Tube
50 Units/Tube
Typical Applications
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specifications
Brochure, BRD8011/D.
*For additional information on our Pb−Free strategy and soldering details, please
download the ON Semiconductor Soldering and Mounting Techniques
Reference Manual, SOLDERRM/D.
©
Semiconductor Components Industries, LLC, 2004
1
October, 2004 − Rev. 8
Publication Order Number:
NCP1207/D
NCP1207
V
out
+
+
OVP and
Demag
1
2
3
4
Universal Network
NCP1207
8
7
6
5
*
GND
+
*Please refer to the application information section
Figure 1. Typical Application
Á
Á
Á
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ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁ
Á
Á Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
PIN FUNCTION DESCRIPTION
Pin No.
1
2
Pin Name
Demag
FB
Function
Description
Core reset detection and OVP
Sets the peak current setpoint
The auxiliary FLYBACK signal ensures discontinuous operation and
offers a fixed overvoltage detection level of 7.2 V.
By connecting an Optocoupler to this pin, the peak current setpoint is
adjusted accordingly to the output power demand. By bringing this pin
below the internal skip level, device shuts off.
3
CS
Current sense input and
skip cycle level selection
The IC ground
Driving pulses
Supplies the IC
−
High−voltage pin
This pin senses the primary current and routes it to the internal
comparator via an L.E.B. By inserting a resistor in series with the pin, you
control the level at which the skip operation takes place.
−
The driver’s output to an external MOSFET.
This pin is connected to an external bulk capacitor of typically 10
mF.
This unconnected pin ensures adequate creepage distance.
Connected to the high−voltage rail, this pin injects a constant current into
the V
CC
bulk capacitor.
4
5
6
7
8
GND
Drv
V
CC
NC
HV
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2
NCP1207
4.5
ms
Delay
Demag
OVP
7.0
mA
+
−
+
V
CC
−
+
PON
+
5.0 V
/1.44
8.0
ms
Blanking
S
S*
R* R Q
12 V, 10 V,
5.3 V (fault)
Q
V
CC
Driver: src = 20
sink = 10
Drv
4.2 V
R
esd
−
+
+
50 mV
R
int
10 V
Demag
HV
To Internal
Supply
GND
Fault
Mngt.
+
−
Soft−Start = 1 ms
/3
FB
1.0 V
Overload?
Timeout
Reset
200
mA
when Drv
is OFF
380 ns
L.E.B.
CS
*S and R are level triggered whereas S is edge
triggered. R has priority over the other inputs.
5.0
ms
Timeout
Demag
Figure 2. Internal Circuit Architecture
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Á
Á Á
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ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Á
Á Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
MAXIMUM RATINGS
Rating
Symbol
Value
16
Units
V
V
Power Supply Voltage
V
CC
, Drv
−
−
Idem
R
qJC
R
qJA
R
qJA
T
J
Maximum Voltage on all other pins except Pin 8 (HV), Pin 6 (V
CC
) Pin 5 (Drv) and
Pin 1 (Demag)
Maximum Current into all pins except V
CC
(6), HV (8) and Demag (1) when 10 V
ESD diodes are activated
Maximum Current in Pin 1
Thermal Resistance, Junction−to−Case
Thermal Resistance, Junction−to−Air, SOIC version
Thermal Resistance, Junction−to−Air, PDIP version
Operating Junction Temperature
Maximum Junction Temperature
Temperature Shutdown
−0.3 to 10
5.0
+3.0/−2.0
57
178
100
−40 to +125
150
155
30
mA
mA
°C/W
°C/W
°C/W
°C
°C
°C
°C
°C
kV
V
V
V
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Á
Á Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Á
Á Á
TJ
MAX
−
−
−
−
−
V
HVMAX
V
HVMIN
Hysteresis in Shutdown
Storage Temperature Range
ESD Capability, HBM Model (All pins except HV)
ESD Capability, Machine Model
Maximum Voltage on Pin 8 (HV), Pin 6 (V
CC
) decoupled to ground with 10
mF
Minimum Voltage on Pin 8 (HV), Pin 6 (V
CC
) decoupled to ground with 10
mF
−60 to +150
2.0
200
500
40
Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit
values (not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied,
damage may occur and reliability may be affected.
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3
NCP1207
ELECTRICAL CHARACTERISTICS
(For typical values T
J
= 25°C, for min/max values T
J
= 0°C to +125°C, Max T
J
= 150°C,
V
CC
= 11 V unless otherwise noted)
Rating
DYNAMIC SELF−SUPPLY
V
CC
Increasing Level at which the Current Source Turns−off
V
CC
Decreasing Level at which the Current Source Turns−on
V
CC
Decreasing Level at which the Latchoff Phase Ends
Internal IC Consumption, No Output Load on Pin 5,
F
SW
= 60 kHz
Internal IC Consumption, 1.0 nF Output Load on Pin 5,
F
SW
= 60 kHz
Internal IC Consumption in Latchoff Phase
INTERNAL STARTUP CURRENT SOURCE
(T
J
u
0°C)
High−voltage Current Source, V
CC
= 10 V
High−voltage Current Source, V
CC
= 0
DRIVE OUTPUT
Output Voltage Rise−time @ CL = 1.0 nF, 10−90% of Output
Signal
Output Voltage Fall−time @ CL = 1.0 nF, 10−90% of Output
Signal
Source Resistance
Sink Resistance
CURRENT COMPARATOR
(Pin 5 Unloaded)
Input Bias Current @ 1.0 V Input Level on Pin 3
Maximum Internal Current Setpoint
Propagation Delay from Current Detection to Gate OFF State
Leading Edge Blanking Duration
Internal Current Offset Injected on the CS Pin during OFF Time
OVERVOLTAGE SECTION
(V
CC
= 11 V)
Sampling Delay after ON Time
OVP Internal Reference Level
FEEDBACK SECTION
(V
CC
= 11 V, Pin 5 Loaded by 1.0 kW)
Internal Pullup Resistor
Pin 3 to Current Setpoint Division Ratio
Internal Soft−Start
DEMAGNETIZATION DETECTION BLOCK
Input Threshold Voltage (V
pin1
Decreasing)
Hysteresis (V
pin1
Decreasing)
Input Clamp Voltage
High State (I
pin
1 = 3.0 mA)
Low State (I
pin
1 = −2.0 mA)
Demag Propagation Delay
Internal Input Capacitance at V
pin1
= 1.0 V
Minimum T
OFF
(Internal Blanking Delay after T
ON
)
Timeout After Last Demag Transition
Pin 1 Internal Impedance
1. Max value at T
J
= 0°C.
1
1
1
1
1
1
1
1
1
V
TH
V
H
VC
H
VC
L
T
dem
C
par
T
blank
T
out
R
int
35
−
8.0
−0.9
−
−
−
−
−
50
20
10
−0.7
210
10
8.0
5.0
28
90
−
12
−0.5
−
−
−
−
−
mV
mV
V
V
ns
pF
ms
ms
kW
2
−
−
Rup
Iratio
Tss
−
−
−
20
3.3
1.0
−
−
−
kW
−
ms
1
1
T
sample
V
ref
−
6.4
4.5
7.2
−
8.0
ms
V
3
3
3
3
3
I
IB
I
Limit
T
DEL
T
LEB
I
skip
−
0.92
−
−
−
0.02
1.0
100
380
200
−
1.12
160
−
−
mA
V
ns
ns
mA
5
5
5
5
T
r
T
f
R
OH
R
OL
−
−
12
5.0
40
20
20
10
−
−
36
19
ns
ns
W
W
8
8
I
C1
I
C2
4.3
−
7.0
8.0
9.6
−
mA
mA
6
6
6
6
6
6
VCC
OFF
VCC
ON
VCC
latch
I
CC1
I
CC2
I
CC3
10.8
9.1
−
−
−
−
12
10
5.3
1.0
1.6
330
12.9
10.6
−
1.3
(Note 1)
2.0
(Note 1)
−
V
V
V
mA
mA
mA
Pin
Symbol
Min
Typ
Max
Unit
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4
NCP1207
TYPICAL CHARACTERISTICS
(T
J
= −40°C to 125°C)
13.2
7
12.8
12.4
VCC
OFF
(V)
12.0
11.6
11.2
10.8
10.4
−50
9.2
8.8
−50
VCC
ON
(V)
−25
0
25
50
75
100
125
10.4
10.0
9.6
11.2
10.8
−25
0
25
50
75
100
125
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 3. V
CC
Increasing Level at which the
Current Source Turns−off versus Temperature
1.60
1.40
1.20
I
CC1
(mA)
1.00
0.80
0.60
0.40
−50
I
CC2
(mA)
2.30
2.10
1.90
1.70
1.50
1.30
1.10
−25
0
25
50
75
100
125
Figure 4. V
CC
Decreasing Level at which the
Current Source Turns−on versus Temperature
−50
−25
0
TEMPERATURE (°C)
25
50
75
TEMPERATURE (°C)
100
125
Figure 5. Internal IC Consumption, No Output
Load on Pin 5 versus Temperature
12
11
10
9
I
C1
(mA)
I
limit
(V)
8
7
6
5
4
3
2
−50
−25
0
25
50
75
TEMPERATURE (°C)
100
125
0.90
−50
1.15
1.10
1.05
1.00
0.95
1.20
Figure 6. Internal IC Consumption, Output
Load on Pin 5 versus Temperature
−25
0
25
50
75
TEMPERATURE (°C)
100
125
Figure 7. Internal Startup Current Source,
V
CC
= 10 V versus Temperature
Figure 8. Maximum Internal Current Setpoint
versus Temperature
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