NCP1237 ONSEMI [ON Semiconductor], NCP1237 Datasheet - Page 6

• Manufacturer Part Number: NCP1237
• Description: Fixed Frequency Current Mode Controller for Flyback Converters
• Manufacturer: ONSEMI [ON Semiconductor]

ELECTRICAL CHARACTERISTICS
V
CURRENT SENSE
OVERPOWER COMPENSATION
FEEDBACK
OVERCURRENT PROTECTION
FREQUENCY FOLDBACK
SKIP CYCLE MODE
6. Internal supply current only, current in FB pin not included (current flowing through GND pin only).
Input Bias Current
Maximum internal current setpoint
Threshold for immediate fault protection activation
Propagation delay from V
Leading Edge Blanking Duration for V
Leading Edge Blanking Duration for V
Slope of the compensation ramp
Soft−start duration
V
Current flowing out of CS pin
FB voltage above which I
FB voltage below which I
Refresh operation for dc operation
Internal pull−up resistor
V
Internal pull−up voltage on the FB pin
Fault timer duration
Autorecovery mode latch−off time duration
CS threshold for transient peak timer activation
Transient peak power timer duration
Feedback voltage threshold below which frequency
foldback starts
Minimum switching frequency
Threshold below which the frequency foldback is
finished and the controller switches at f
Feedback voltage thresholds for skip mode
Soft−skip duration
CC
HV
FB
= 11 V unless otherwise noted)
to internal current setpoint division ratio
to I
OPC
conversion ratio
Characteristics
OPC
OPC
ILIM
detection to DRV off
= 0
is applied
ILIM
CS(stop)
OSC(min)
(For typical values T
http://onsemi.com
V
V
V
From 1
V
V
V
V
V
T
From CS reaching V
DRV stop
V
From 1
V
V
V
V
From 1
V
CS
FB
CS
CS
HV
HV
HV
HV
J
CS(peak)
CS(tran)
FB
FB
FB
FB(fold)
= 25°C
J
> 3.5 V
= V
going down
going up
= 0.7 V
= V
= V
= 125 V
= 162 V
= 325 V
= V
= 25°C, for min/max values T
Test Condition
st
st
st
skip(in)
ILIM
ILIM
HV(OV2)
/ K
to DRV stop
time V
pulse to V
pulse to
6
= V
FB
ILIM
+ 0.2 V
CS
− 5 V
– 5%
>
CS
ILIMIT
=
to
S
V
V
comp(65kHz)
I
I
I
I
V
V
f
V
Symbol
V
OPC(max)
V
FB(endfold)
t
OPC(125)
OPC(162)
OPC(325)
OSC(min)
FB(OPCE)
R
V
V
t
SSTART
FB(OPC)
t
CS(stop)
skip(out)
K
autorec
CS(tran)
V
t
FB(fold)
J
SSKIP
t
FB(ref)
skip(in)
I
t
FB(up)
K
t
delay
t
t
BCS
LEB
fault
bias
OPC
tran
WD
ILIM
= −40°C to +125°C, V
FB
0.665
0.95
1.50
0.47
0.63
0.72
Min
190
102
117
2.8
4.7
4.3
1.0
1.3
50
90
25
15
64
21
−
−
−
−
−
−
−
−
−
−32.5
0.02
1.05
1.65
1.25
0.80
Typ
250
120
104
120
156
100
0.7
4.0
0.5
5.0
5.0
1.4
0.5
1.4
1.0
0.7
80
52
35
20
78
27
0
HV
= 120 V,
0.735
Max
1.15
1.80
0.53
0.77
0.88
310
150
138
195
110
5.2
5.3
5.7
1.8
1.5
45
25
98
31
−
−
−
−
−
−
−
−
−
mV / ms
mA / V
Unit
kHz
ms
ms
kW
ms
ms
mA
mA
ns
ns
ns
ms
V
V
V
V
V
V
V
V
V
−
s