LNK302PN Power Integrations, LNK302PN Datasheet - Page 7
![IC OFFLINE SWIT OCP 8DIP](/photos/7/32/73217/596-8-bdip_sml.jpg)
LNK302PN
Manufacturer Part Number
LNK302PN
Description
IC OFFLINE SWIT OCP 8DIP
Manufacturer
Power Integrations
Series
LinkSwitch®-TNr
Type
Off Line Switcherr
Datasheet
1.LNK302GN-TL.pdf
(20 pages)
Specifications of LNK302PN
Output Isolation
Non-Isolated
Frequency Range
62 ~ 70kHz
Voltage - Output
700V
Power (watts)
12mW
Operating Temperature
-40°C ~ 150°C
Package / Case
8-DIP (0.300", 7.62mm), 7 Leads
Output Voltage
12 V
Input / Supply Voltage (max)
265 VAC
Input / Supply Voltage (min)
85 VAC
Duty Cycle (max)
72 %
Switching Frequency
66 KHz
Supply Current
200 uA
Operating Temperature Range
- 40 C to + 150 C
Mounting Style
Through Hole
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
596-1021-5
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
LNK302PN
Manufacturer:
POWER
Quantity:
15 000
Part Number:
LNK302PN
Manufacturer:
POWER
Quantity:
20 000
provides the lowest cost and highest effi ciency converter. CCM
designs require a larger inductor and ultra-fast (t
freewheeling diode in all cases. It is lower cost to use a larger
LinkSwitch-TN in MDCM than a smaller LinkSwitch-TN in CCM
because of the additional external component costs of a CCM
design. However, if the highest output current is required, CCM
should be employed following the guidelines below.
Topology Options
LinkSwitch-TN can be used in all common topologies, with or
without an optocoupler and reference to improve output voltage
tolerance and regulation. Table 2 provide a summary of these
confi gurations. For more information see the Application
Note – LinkSwitch-TN Design Guide.
Component Selection
Referring to Figure 5, the following considerations may be
helpful in selecting components for a LinkSwitch-TN design.
Freewheeling Diode D1
Diode D1 should be an ultra-fast type. For MDCM, reverse
recovery time t
70 °C or below. Slower diodes are not acceptable, as continuous
mode operation will always occur during startup, causing high
leading edge current spikes, terminating the switching cycle
prematurely, and preventing the output from reaching regulation.
If the ambient temperature is above 70 °C then a diode with
t
For CCM an ultra-fast diode with reverse recovery time
t
leading edge current spikes, terminating the switching cycle
prematurely and preventing full power delivery.
Fast and slow diodes should never be used as the large reverse
recovery currents can cause excessive power dissipation in the
diode and/or exceed the maximum drain current specifi cation
of LinkSwitch-TN.
Table 2 (cont). Common Circuit Confi gurations Using LinkSwitch-TN.
rr
rr
Low-Side
Buck Boost –
Optocoupler
Feedback
TOPOLOGY
≤35 ns should be used.
≤35 ns should be used. A slower diode may cause excessive
rr
≤75 ns should be used at a temperature of
V
+
IN
LinkSwitch-TN
BASIC CIRCUIT SCHEMATIC
S
BP
FB
D
rr
≤35 ns)
PI-3756-111903
Feedback Diode D2
Diode D2 can be a low-cost slow diode such as the 1N400X
series, however it should be specifi ed as a glass passivated type
to guarantee a specifi ed reverse recovery time. To a fi rst order,
the forward drops of D1 and D2 should match.
Inductor L1
Choose any standard off-the-shelf inductor that meets the
design requirements. A “drum” or “dog bone” “I” core
inductor is recommended with a single ferrite element due to
its low cost and very low audible noise properties. The typical
the LinkSwitch-TN design spreadsheet available within the
PI Expert design suite from Power Integrations. Choose L1
greater than or equal to the typical calculated inductance with
RMS current rating greater than or equal to calculated RMS
inductor current.
Capacitor C2
The primary function of capacitor C2 is to smooth the inductor
current. The actual output ripple voltage is a function of this
capacitor’s ESR. To a fi rst order, the ESR of this capacitor
should not exceed the rated ripple voltage divided by the typical
current limit of the chosen LinkSwitch-TN.
Feedback Resistors R1 and R3
The values of the resistors in the resistor divider formed by
R1 and R3 are selected to maintain 1.65 V at the FB pin. It is
recommended that R3 be chosen as a standard 1% resistor of
2 kΩ. This ensures good noise immunity by biasing the feedback
network with a current of approximately 0.8 mA.
Feedback Capacitor C3
Capacitor C3 can be a low cost general purpose capacitor. It
provides a “sample and hold” function, charging to the output
voltage during the off time of LinkSwitch-TN. Its value should
be 10 μF to 22 μF; smaller values cause poorer regulation at
light load conditions.
inductance value and RMS current rating can be obtained from
V
+
O
1. Output referenced to input
2. Positive output (V
3. Step up/down – V
4. Optocoupler feedback
5. Fail-safe – output is not subjected to input
- Accuracy only limited by reference
- Low cost non-safety rated opto
- No pre-load required
voltage if the internal MOSFET fails
choice
KEY FEATURES
LNK302/304-306
O
O
) with respect to +V
> V
IN
or V
O
< V
IN
Rev. I 11/08
IN
2-7
7