NCP1601A, NCP1601B
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3
PIN FUNCTION DESCRIPTION
Pin Symbol Function Function
1 FB Feedback /
Shutdown
This pin receives a current I
FB
which is proportional to the PFC circuit output voltage. The current is
for the output regulation, output Overvoltage Protection (OVP), and output undervoltage protection
(UVP).
When I
FB
goes above 107% I
ref
, OVP is activated and the Drive Output is disabled.
When I
FB
goes below 8% I
ref
, the device enters a low−current consumption shutdown mode.
2 V
control
Control The voltage of this pin V
control
directly controls the input impedance and hence the power factor of
the circuit. This pin is connected to an external capacitor to limit the control voltage V
control
band-
width typically below 20 Hz to achieve Power Factor Correction.
3 Ramp Ramp This pin is connected to an external capacitor to set a ramp signal. The capacitor value directly
affects the input impedance of the PFC circuit and hence the maximum input power.
4 CS Current Sense This pin sources a current I
S
which depends on the inductor current and an offset voltage. The
current is for Overcurrent Protection (OCP) and zero current detection.
When I
S
is above 200 mA, OCP is activated and the Drive Output is disabled.
When I
S
is below 14 mA, the circuit detects a zero current. This information is used by the on−time
modulation arrangement and by the oscillator block.
5 Osc Oscillator /
Synchronization
In oscillator mode, this pin is connected to an external capacitor to set the oscillator frequency of
the DCM operation.
In synchronization mode, this pin is connected to an external driving signal. The positive edge of the
drive output is synchronized to the negative edge of the external signal in DCM operation.
If the inductor current is non−zero at the end of a switching period, the output drive is not allowed to
turn on. CCM operation is prohibited. Instead, the circuit operates in CRM in this case.
6 GND The IC ground −
7 Drv Drive Output This pin provides an output to an external MOSFET.
8 V
CC
Supply Voltage This pin is the positive supply of the device. The operating range is between 9 V and 18 V with
UVLO start threshold 13.75 V for NCP1601A and 10.5 V for NCP1601B.
MAXIMUM RATINGS
Rating Symbol Value Unit
FB, V
control
, Ramp, CS, Osc Pins (Pins 1−5)
Maximum Voltage Range
Maximum Current
V
max
I
max
−0.3 to +9
100
V
mA
Drive Output (Pin 7)
Maximum Voltage Range
Maximum Current Range (Note 2)
V
max
I
max
−0.3 to +18
−500 to +750
V
mA
Power Supply Voltage (Pin 8)
Maximum Voltage Range
Maximum Current
V
max
I
max
−0.3 to +18
100
V
mA
Power Dissipation and Thermal Characteristics
P suffix, Plastic Package, Case 626
Maximum Power Dissipation @ T
A
=70 °C
Thermal Resistance, Junction−to−Air
D suffix, Plastic Package, Case 751
Maximum Power Dissipation @ T
A
=70 °C
Thermal Resistance, Junction−to−Air
P
D
R
q
JA
P
D
R
q
JA
800
100
450
178
mW
°C/W
mW
°C/W
Operating Junction Temperature Range T
J
−40 to +125 °C
Storage Temperature Range T
stg
−65 to +150 °C
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.
A. This device series contains ESD protection and exceeds the following tests:
Pins 1−8: Human Body Model 2000 V per MIL−STD−883, Method 3015.
Machine Model Method 200 V.
B. This device contains Latchup protection and exceeds ±100 mA per JEDEC Standard JESD78.
1. Guaranteed by design.
