DPA423GN Power Integrations, DPA423GN Datasheet - Page 9

• Manufacturer Part Number: DPA423GN
• Description: IC CONV DC-DC DPA SWITCH 8SMD
• Manufacturer: Power Integrations
• Series: DPA-Switch®r

Specifications of DPA423GN

• Applications: Converter, Power Over Ethernet and Telecom Applications
• Voltage - Input: 16 ~ 75 V
• Number Of Outputs: 1
• Voltage - Output: 220V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-SMD Gull Wing
• Output Voltage: 9 V
• Output Current: 1.75 A
• Input Voltage: - 0.3 V to + 220 V
• Switching Frequency: 282 KHz to 425 KHz
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: SMD/SMT
• Duty Cycle (max): 79 %
• For Use With: 596-1195 - KIT REF DES DPA 6.6W DC-DC CONV596-1009 - KIT DESIGN ACCELERATOR DC-DC596-1007 - KIT DESIGN ACCELERATOR POE CONV
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Using Feature Pins
FREQUENCY (F) Pin Operation
The FREQUENCY pin is a digital input pin. Shorting the
FREQUENCY pin to SOURCE pin selects the nominal
switching frequency of 400 kHz (Figure 9) which is suited for
most applications. For other applications that may benefit from
lower switching frequency, a 300 kHz switching frequency can
be selected by shorting the FREQUENCY pin to the CONTROL
pin (Figure 10). This pin should not be left open.
LINE-SENSE (L) Pin Operation
When current is fed into the LINE-SENSE pin, it works as a
voltage source of approximately 2.6 V up to a maximum current
of +240 µA (typical). At +240 µA, this pin turns into a constant
current sink. Refer to Figure 8. In addition, a comparator with
a threshold of 1 V is connected at the pin and is used to detect
when the pin is shorted to the SOURCE pin.
There are a total of five functions available through the use of
the LINE-SENSE pin: OV, UV, line feed-forward with DC
reduction, remote ON/OFF and synchronization. Shorting the
LINE-SENSE pin to the SOURCE pin disables all five functions.
The LINE-SENSE pin is typically used for line sensing by
connecting a resistor from this pin to the positive input DC
voltage bus to implement OV, UV and line feed-forward with
DC
the resistor determines the line OV/UV thresholds, and the
DC
from just above the UV threshold. This pin can also be used
as the input pin for remote ON/OFF and synchronization.
An external transistor placed between the LINE-SENSE pin
and the CONTROL pin realizes remote ON/OFF via UV or
OV threshold. Synchronization is available by connecting
an open drain external MOSFET between the LINE-SENSE
Table 2. Typical LINE-SENSE and EXTERNAL CURRENT LIMIT Pin Configurations.
Figure Number
Three Terminal Operation
Under-Voltage
Overvoltage
Line Feed-Forward (DC
Overload Power Limiting
External Current Limit
Remote ON/OFF
Synchronization
*This table is only a partial list of many LINE-SENSE and EXTERNAL CURRENT LIMIT pin configurations that are possible.
MAX
MAX
is reduced linearly with input DC high voltage starting
reduction over line voltage. In this mode, the value of
LINE-SENSE AND EXTERNAL CURRENT LIMIT PIN TABLE*
MAX
)
11
✓
12
✓
✓
✓
13
✓
14
✓
MAX
15
✓
pin and the SOURCE pin to generate synchronization pulse.
Each time the MOSFET turns on, the falling edge of the
LINE-SENSE pin voltage initiates a new switching cycle. The
lowest synchronization frequency guaranteed by DPA-Switch is
128 kHz. Refer to Table 2 for possible combinations of the
functions with example circuits shown in Figure 11 through
Figure 24. A description of specific functions in terms of the
LINE-SENSE pin I/V characteristic is shown in Figure 7 (right
hand side). The horizontal axis represents LINE-SENSE pin
current with positive polarity indicating currents flowing into
the pin. The meaning of the vertical axes varies with functions.
For those that control the on/off states of the output such as
UV, OV and remote ON/OFF, the vertical axis represents
the enable/disable states of the output. UV triggers at I
(+50 µA typical with 4 µA hysteresis) and OV triggers at I
(+135 µA typical with 4 µA hysteresis). Between the UV and
OV thresholds, the output is enabled. For line feed-forward with
DC
of the DC
maximum duty cycle from 75% at I
33% at I
EXTERNAL CURRENT LIMIT (X) Pin Operation
When current is drawn out of the EXTERNAL CURRENT
LIMIT pin, it works as a voltage source of approximately
1.3 V up to a maximum current of -230 µA (typical). At
-230 µA, it turns into a constant current source (refer to Figure 8).
There are two functions available through the use of the
EXTERNAL CURRENT LIMIT pin: external current limit
and remote ON/OFF. Shorting the EXTERNAL CURRENT
LIMIT pin and SOURCE pin disables both functions. In high
efficiency applications, this pin can be used to reduce the current
limit externally to a value close to the operating peak current,
by connecting the pin to the SOURCE pin through a resistor.
16
MAX
✓
✓
reduction, the vertical axis represents the magnitude
OV
MAX
17
✓
(+135 µA).
Line feed-forward with DC
18
✓
19
✓
✓
20
✓
✓
L(DC)
21
✓
✓
✓
✓
✓
DPA423-426
MAX
(+55 µA typical) to
22
✓
✓
✓
✓
reduction lowers
23
✓
✓
✓
✓
7/05
P
24
✓
9
UV
OV