NCP1201D60R2 ON Semiconductor, NCP1201D60R2 Datasheet - Page 10

• Manufacturer Part Number: NCP1201D60R2
• Description: IC CTRLR PWM CM OTP 8SOIC
• Manufacturer: ON Semiconductor

Specifications of NCP1201D60R2

• Output Isolation: Isolated
• Frequency Range: 52 ~ 72kHz
• Voltage - Input: 12.5 ~ 16 V
• Voltage - Output: 500V
• Operating Temperature: -40°C ~ 150°C
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Number Of Outputs: 1
• Duty Cycle (max): 83 %
• Output Voltage: - 0.3 V to + 6.5 V
• Output Current: 250 mA
• Mounting Style: SMD/SMT
• Switching Frequency: 60 KHz
• Operating Supply Voltage: - 0.3 V to + 16 V
• Maximum Operating Temperature: + 150 C
• Fall Time: 41 ns
• Minimum Operating Temperature: - 40 C
• Rise Time: 116 ns
• Synchronous Pin: No
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: NCP1201D60R2OS

Introduction
architecture where the switch- -off time is dictated by the peak
current setpoint. This component represents the ideal
candidate where low part- -count is the key criteria,
particularly in low- -cost AC- -DC adapters, auxiliary supplies
etc. Due to its high- -performance High- -Voltage technology,
the NCP1201 incorporates all the necessary components
normally needed in UC384X based supplies: timing
components, feedback devices, low- -pass filter and
self- -supply. This later point emphasizes the fact that
ON Semiconductor’s NCP1201 does NOT need an auxiliary
winding to operate: the device is self supplied from the
high- -voltage rail and delivers a V
is named the Dynamic Self- -Supply (DSS).
consumption and the MOSFET’s gate charge Qg. If we
select a MOSFET like the MTP2N60E, Qg max equals
22 nC. With a maximum switching frequency of 70 kHz for
the oscillator 60 kHz, the average power necessary to drive
the MOSFET (excluding the driver efficiency and
neglecting various voltage drops) is:
Where,
P
F
Qg = MOSFET’s gate charge
V
divide Pdriver by V
driver
sw(max)
CC
The NCP1201 implements a standard current mode
The DSS behavior actually depends on the internal IC
To obtain an estimation of the driving current, simply
= VGS level applied to the gate of the MOSFET
= Average Power to drive the MOSFET
= Maximum switching frequency
I driver = F sw(max) × Q g = 1.54 mA
P driver = F sw(max) × Q g × V CC
CC
,
Figure 27. The Charge/Discharge Cycle Over a 10 mF V
CC
10 mS
Vripple = 2 V
to the IC. This system
DETAILED OPERATING DESCRIPTION
30 mS
ON
VCC
http://onsemi.com
(eq. 1)
(eq. 2)
OFF
50 mS
= 12.5 V
10
Output Pulses
VCC
Dynamic Self- -Supply
V
can easily describe the current source operation following
simple logic equations:
POWER- -ON: IF V
IF VCC decreasing > V
IF VCC increasing < V
Typical values are: V
sketch offers the necessary explanation,
therefore heavily rely on the internal IC current
consumption plus the driving current (altered by the driver’s
efficiency). Suppose that the IC is supplied from a 350 VDC
line. The current flowing through pin 8 is a direct image of
the NCP1201 current consumption (neglecting the
switching losses of the HV current source). If I
2.1 mA @ T
IC is simply: 350 V x 2.1 mA = 735 mW. For design and
reliability reasons, it would be interesting to reduce this
source of wasted power. In order to achieve that, different
methods can be used.
CC
70 mS
The DSS principle is based on the charge/discharge of the
To better understand the operation principle, Figure 27
ON
The total standby power consumption at no- -load will
Current Source is ON, no output pulses
Current Source is OFF, output is pulsing
Current Source is ON, output is pulsing
bulk capacitor from a low level up to a higher level. We
1. Use a MOSFET with lower gate charge Qg;
2. Connect pin through a diode (1N4007 typically) to
= 10.5 V
OFF
one of the mains input. The average value on pin 8
becomes:
A
90 mS
= 25C, then the power dissipated (lost) by the
CC
CC
V mainsPEAK × 2
V
Current
Source
CCOFF
CC
Capacitor
< V
CCOFF
CCON
CCOFF
= 12.5 V, V
π
THEN
THEN
THEN
CCON
= 10.5 V
CC2
equals
(eq. 3)