NCP1249
High-Voltage Current-Mode
PWM Controller Featuring
Peak Power Excursion and
Extremely Low Stand-by
Power Consumption
The NCP1249 is a highly integrated high−voltage PWM controller
capable of delivering a rugged and high performance offline power
supply with extremely low no−load consumption. With a supply range
up to 30 V, the controller hosts a jittered 65−kHz switching circuitry
operated in peak current mode control. When the power on the
secondary side starts to decrease, the controller automatically folds
back its switching frequency down to a minimum level of 26 kHz. As
the power further goes down, the part enters skip cycle while freezing
the peak current setpoint.
To help build rugged converters, the controller features several key
protective features: a internal brown−out, a non−dissipative Over
Power Protection for a constant maximum output current regardless of
the input voltage and two latched over voltage protection inputs −
either through a dedicated pin or via the VCC input.
The controller architecture is arranged to authorize a transient peak
power excursion when the peak current hits the limit. At this point, the
switching frequency is increased from 65 kHz to 130 kHz until the
peak requirement disappears. The timer duration is then modulated as
the converter crosses a peak power excursion mode (long) or
undergoes a short circuit (short).
NCP1249 comes in both Active ON (A and B versions) and Active
OFF (C and D versions).
Features
9
1
SOIC−9 NB
D SUFFIX
CASE 751BP
1
NCP1249x65 = Specific Device Code
x
= A, B, C, D
A
= Assembly Location
L
= Wafer Lot
Y
= Year
W
= Work Week
G
= Pb−Free Package
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MARKING DIAGRAM
9
NCP1249x65
ALYW
G
PIN CONNECTIONS
1
X2
HV
REM
VCC
FB
DRV
CS
GND
OPP/LATCH
NCP1249A/B (Top View)
1
X2
FB/REM
OPP/Latch
Timer
HV
•
•
•
•
•
•
•
•
•
•
•
•
•
High−voltage Current Source for Lossless Start−up Sequence
V
CC
Remote Input for Standby Operation Control
DRV
GND
Automatic and Lossless X2 Capacitors Discharge Function
NCP1249C/D (Top View)
65−kHz Fixed−frequency Current−mode Control Operation with
130−kHz Excursion
Internal and Adjustable Over Power Protection (OPP)
•
+300 mA/ −500 mA Source/Sink Drive Capability
Circuit
•
Extremely Low No−load Standby Power
Internal Brown−Out Protection Circuit
•
Option for Auto−Recovery or Latched Short−Circuit
Frequency Foldback down to 26 kHz and Skip−cycle in
Protection
Light Load Conditions
•
Internal Thermal Shutdown with Hysteresis
Adjustable Ramp Compensation
•
These are Pb−Free Devices
Internally Fixed 4−ms Soft−start
Typical Applications
100% to 25% Timer Reduction from Overload to
•
Converters Requiring Peak−power Capability such as
Short−circuit Fault
Printers Power Supplies, ac−dc Adapters for Game
Frequency Jittering in Normal and Frequency Foldback
Stations
Modes
Latched OVP Input for Improved Robustness and
ORDERING INFORMATION
Latched OVP on V
cc
See detailed ordering and shipping information in the package
dimensions section on page 3 of this data sheet.
Up to 30 V V
cc
Maximum Rating
1
Publication Order Number:
NCP1249/D
©
Semiconductor Components Industries, LLC, 2015
May, 2015 − Rev. 2
NCP1249
Figure 1. Typical Application Example − NCP1249 (A/B)
Vbulk
L1
L2
.
.
V
out
OVP
.
OPP
L1
L2
1
2
3
4
5
10
9
8
7
6
NCP1249
ramp
comp.
Figure 2. Typical Application Example − NCP1249 (C/D)
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2
NCP1249
Table 1. PIN FUNCTIONS
A/B
1
2
3
4
5
C/D
1
2
2
3
4
Pin Name
X2
REM
FB
CS
OPP/Latch
Function
X2−capacitors discharge
Remote input
Feedback pin
Current sense + ramp
compensation
Adjust the Over Power Protection
Latches off the part
−
Driver output
Supplies the controller
−
High−voltage input
Pin Description
When the voltage on this pin disappears,
the controller ensures the X2−capacitors discharge.
Initiates ultra low consumption mode (off−mode) when brought
above 8 V (A/B) or below 0.4 V (C/D).
Connecting an opto−coupler to this pin allows regulation.
This pin monitors the primary peak current but also offers
a means to introduce slope compensation.
A resistive divider from the auxiliary winding to this pin sets the
OPP compensation level. When brought above 3 V, the part is
fully latched off.
The controller ground.
The driver’s output to an external MOSFET gate.
This pin is connected to an external auxiliary voltage and supplies
the controller. When above a certain level, the part fully latches off.
Increases insulation distance between high and low voltage pins.
This pin provides a charging current during start−up and
auto−recovery faults but also a means to efficiently discharge
the input X2 capacitors.
A resistor to ground adjusts the timer duration in fault condition.
6
7
8
9
10
6
7
8
9
10
GND
DRV
VCC
NC
HV
X
5
TIMER
Fault timer adjustment
Table 2. MAXIMUM RATINGS TABLE
Symbol
V
cc
V
HV
I
HV
Vpin_x
V
DRV
I
OPP
R
θJ−A
T
J,max
Rating
Power Supply voltage, VCC pin, continuous voltage
High Voltage (HV) Pin (pin 10)
High Voltage (pin 10) Input Current
Maximum voltage on low power pins (X2, REM, FB, CS, OPP)
Maximum voltage on drive pin
Maximum injected current into the OPP pin
Thermal Resistance Junction−to−Air
Maximum Junction Temperature
Storage Temperature Range
ESD Capability, HBM model (All pins except HV) per JEDEC standard JESD22, Method A114E
ESD Capability, Machine Model per JEDEC standard JESD22, Method A115A
Value
−0.3 to 30
–0.3 to 500
20
−0.3 to 10
−0.3 to V
cc
+0.3
−2
211
150
−60 to +150
2
200
Unit
V
V
mA
V
V
mA
°C/W
°C
°C
kV
V
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality
should not be assumed, damage may occur and reliability may be affected.
1. This device contains latch−up protection and exceeds 100 mA per JEDEC Standard JESD78.
Table 3. OPTIONS AND ORDERING INFORMATION
Device
NCP1249AD65R2G
NCP1249BD65R2G
NCP1249CD65R2G
NCP1249DD65R2G
Overload
Protection
Latched
Autorecovery
Latched
Autorecovery
Switching
Frequency
65 kHz
65 kHz
65 kHz
65 kHz
Peak Frequency
130 kHz
130 kHz
130 kHz
130 kHz
SOIC−9
(Pb−Free)
2500 / Tape &
Reel
Package
Shipping†
†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.
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3
NCP1249
X2
TSD
Brown−
out
R X2
timer
REM
Remote
timer
Q
Q
S
R
HV
startup
BO _OK
BO _bias EN
VHV
HV
REM
timer
OPP/
Latch
Vcc management,
600 ns time
constant
logic and fault timer
hiccup
Vlatch
OVP
gone ?
Up
counter
RST
4
Vdd
POR
UVLO
IpFlag
20 s time
constant
VOVP
Idischarge
VCC
S
R
VDD
Q
Q
X2 & Vcc discharge
1 s
blanking
Resets
if Vcc < 3 V
65 kHz
clock
Frequency
modulation
S
R
Q
Q
Clamp
Frequency
foldback
Vfold
DRV
Vskip
Rramp
vdd
RFB
4 ms
SS
IpFlag
The soft−
start is activated during :
−the startup sequence
−the auto−
recovery burst mode
FB
VOPP
/PWM_ ON
CS
LEB
Vlimit
+
Vlimit + VOPP
300 mV
peak
Current
freeze
GND
Figure 3. Internal Circuit Architecture − NCP1249 (A/B)
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4
NCP1249
X2
HV
X2 timer
TSD
Vrem
BO_OK
BO_bias en
Rem
Integrated
BO sensor
FB
X2_dis
OPP/
LATCH
600−ns time
constant
Vdd
FB_Ipull
Vcc and logic
management
hiccup
UVLO
Vcc
Vref
power
on reset
Vlatch
OVP
gone?
Up counter
RST
4
Vcc
20 us
VOVP
100% to
25% change
SC
option
latch/AR
Ct
Upper
/ lower
limit
TIMER
S
Q
Q
IpFlag, PON reset
R
Rst if
Vcc < 3 V
1 us
blanking
VCC
Rlimit
X2_dis
The BO signal serves as:
− a general reset
− a reset to the latch mode
Jitter
mod.
65 kHz
clock
Clamp
BO_OK
S
Q
Q
R
Frequency
increase to
130 kHz
Frequency
foldback
DRV
VFswp
Vskip
Vfold
vdd HV_leak
Rramp
4 ms
SS
The soft−start is activated during:
− the startup sequence
− the auto−recovery burst mode
FB_Ipull
SC
Ip
flag
RFB
FB/REM
FB
/4
VSC
VFB < 1 V ? setpoint = 250 mV
VOPP
250 mV
peak current
freeze
+
Vlimit + VOPP
CS
LEB
GND
Vlimit
Figure 4. Internal Circuit Architecture − NCP1249 (C/D)
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