NCP1010, NCP1011, NCP1012, NCP1013, NCP1014
PIN FUNCTION DESCRIPTION
Pin No.
(SOT−223)
1
Pin No.
(PDIP−7,
PDIP−7/Gull Wing)
1
Pin Name
V
CC
Function
Powers the Internal Circuitry
Description
This pin is connected to an external capacitor of typi-
cally 10
mF.
The natural ripple superimposed on the
V
CC
participates to the frequency jittering. For im-
proved standby performance, an auxiliary V
CC
can be
connected to Pin 1. The V
CC
also includes an active
shunt which serves as an opto fail−safe protection.
−
−
By connecting an optocoupler to this pin, the peak
current setpoint is adjusted accordingly to the output
power demand.
The internal drain MOSFET connection.
−
−
−
−
−
2
2
3
4
NC
GND
FB
−
The IC Ground
Feedback Signal Input
3
−
−
4
5
−
7
8
Drain
−
GND
GND
Drain Connection
−
The IC Ground
The IC Ground
V
CC
V
CC
1
Vclamp*
IV
CC
I?
Startup Source
Drain
Iref = 7.4 mA
IV
CC
−
+
Rsense
8 GND
UVLO
Management
High when V
CC
t
3 V
R
S
Q
250 ns
L.E.B.
NC 2
4V
Reset
EMI Jittering
65, 100 or
130 kHz
Clock
Set
Flip−Flop
DCmax = 65%
Reset
18 k
Error flag armed?
V
CC
Q
Driver
7 GND
GND 3
0.5 V
Overload?
+
−
−
+
+
−
Soft−Start
FB 4
Startup Sequence
Overload
Drain
5 Drain
*Vclamp = VCC
OFF
+ 200 mV (8.7 V Typical)
Figure 2. Simplified Internal Circuit Architecture
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