RDK-252 Power Integrations, RDK-252 Datasheet - Page 7

• Manufacturer Part Number: RDK-252
• Description: KIT REF DESIGN DG CAPZERO
• Manufacturer: Power Integrations
• Series: CAPZero™r
• Type: Other Power Managementr

Specifications of RDK-252

• Main Purpose: Automatic X Capacitor Discharge
• Embedded: No
• Utilized Ic / Part: CAP014DG, CAP002DG, CAP012DG
• Primary Attributes: Low No-Load Input Power (
• Secondary Attributes: Surge Testing to EN6100-4-5 Class 4
• Input Voltage: 85 V to 264 V
• Board Size: 38.1 mm x 25.4 mm
• Product: Power Management Modules
• Dimensions: 38.1 mm x 25.4 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: CAP014DG
• Other names: 596-1313

Figure 8. Circuit Protection Component Section of Design Spreadsheet.
PROTECTION FEATURES
LINE SENSING
VUV_STARTUP
VOV_SHUTDOWN
RLS
OUTPUT OVERVOLTAGE
VZ
RZ
OVERLOAD POWER LIMITING
Overload Current Ratio at VMAX
Overload Current Ratio at VMIN
ILIMIT_EXT_VMIN
ILIMIT_EXT_VMAX
RIL
RPL
CURRENT WAVEFORM SHAPE PARAMETERS
DMAX
IAVG
IP
IR
IRMS
Figure 7 shows K
mode, K
secondary diode conduction time.
The value of K
guidance is given in the comments cell if the value is outside this
range.
A K
primary RMS current. A K
for 230 VAC (compared to between 0.4 and 0.6 for 100/115 VAC
and universal input) to accommodate for a significantly taller and
wider leading edge current spike caused by the discharge of the
drain node capacitance at higher voltage levels.
The spreadsheet will calculate the values of peak primary
current, the RMS ripple current, average primary current and the
maximum duty cycle for the design.
Step 3 – Choose Protection Features, Line Under /
Overvoltage, Output Overvoltage and Overload Power
Limiting - Optional
The optional line undervoltage lockout feature of TOPSwitch-JX,
defines the start-up voltage of the supply and prevents the
power supply output from glitching when the input voltage is
below the normal operating range. Connecting a resistor from
the input capacitor to the V pin enables this feature. Enter the
desired DC voltage across the input capacitor, at which the
power supply should operate in the cell adjacent to V
The spread-sheet calculates the closest standard 5% resistor
value R
The value of R
at which the power supply will stop operating due to an input
overvoltage condition is displayed in the cell adjacent to
V
www.powerint.com
AN-47
OV(SHUTDOWN)
P
value of <1 will result in higher efficiency by lowering the
LS
P
.
is the ratio of primary MOSFET off time to the
.
P
LS
should be in the range of 0.3 < K
K
also defines the line OV threshold. The voltage
P
P
≥ 1, indicating discontinuous conduction
/
K
DP
K
P
=
P
between 0.6 and 0.8 is recommended
/
^
V
V
K
MIN
OR
RP
#
-
=
^
V
1
I
I
DS
R
P
-
h
#
D
MAX
D
MAX
h
P
< 6, and
UV(START-UP)
N/A
11.74 k-ohms
1.08
1.16 A
1.04 A
0.68
0.59 Amps
1.16 Amps
0.58 Amps
0.73 Amps
445 Volts
4.0 M-ohms
5.1 k-ohms
1.2
95 Volts
22 Volts
.
M-ohms
Output Overvoltage Shutdown - Optional
The output voltage of the bias winding can be used to provide
primary sensed output overvoltage. This is an inexpensive way
of protecting the power supply should a component in the
feedback circuit fail.
This feature can be enabled by connecting a series combination
of a resistor and Zener diode from the bias winding output to the
V pin (as shown in Figure 1). The spreadsheet estimates a value
of the Zener diode required to initiate shutdown in case of loss of
feedback but without false triggering during transient conditions
such as during dynamic load changes.
During a fault, the bias winding voltage rises causing the Zener
diode to conduct and current to flow into the V pin. If this current
exceeds 112 µA (I
can resume anytime if this current falls below 108 µA within
100 µs. After 100 µs however, the supply enters auto-restart
mode. This prevents further increase in output voltage but does
not latch off the power supply. Switching is enabled again when
the current reduces by greater than the 4 µA, V pin hysteresis
requirement. If the current through the Zener and into the V pin
exceeds 336 µA, the latching shutdown feature of TOPSwitch-JX
is triggered, and the power supply latches off. To reset the
latched condition, either the input AC supply has to be removed,
long enough for the CONTROL pin capacitor to discharge below
V
In a typical circuit, a high series resistance R
5.1 kW will result in a non-latching shutdown. A low resistance in
the range of 4.7 W to 22 W will result in a latching shutdown.
To avoid noise coupling it is recommended that the resistor
should be connected to the V pin and the Zener diode cathode
should be connected to the bias winding output.
With the OVP components fitted there is an additional ~2s delay
from applying AC (above the line UV threshold) to the supply
operating. This delay is caused by the time for the V pin to
charge the bias winding capacitor via R
be prevented by adding a small signal (e.g. BAV21/1N4148) diode
in series with V
C(RESET)
V pin functionality
Minimum DC Bus Voltage at which the power supply will start-up
Typical DC Bus Voltage at which power supply will shut-down (Max)
Use two standard, 2 M-Ohm, 5% resistors in series for line sense functionality.
Zener Diode rated voltage for Output Overvoltage shutdown protection
Output OVP resistor. For latching shutdown use 20 ohm resistor instead
X pin functionality
Enter the desired margin to current limit at VMAX. A value of 1.2 indicates that the current limit should
be 20% higher than peak primary current at VMAX
Margin to current limit at low line.
Peak primary Current at VMIN
Peak Primary Current at VMAX
Current limit/Power Limiting resistor.
Resistor not required. Use RIL resistor only
Maximum Duty Cycle (calculated at PO_PEAK)
Average Primary Current (calculated at average output power)
Peak Primary Current (calculated at Peak output power)
Primary Ripple Current (calculated at average output power)
Primary RMS Current (calculated at average output power)
(~3 V) or when the X pin current falls below 27 µA.
ROVP
OV
), switching is immediately disabled. Switching
(see Figure 21).
Application Note
OVP
and V
OVP
in the order of
ROVP
. This can
Rev. A 030910
7