RD7 Просмотр технического описания (PDF) - Power Integrations, Inc
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производитель
RD7
Power Integrations, Inc
RD7 Datasheet PDF : 12 Pages
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RD7
RF1
+ 1Ω
Fusible
90-375 VDC
Input
-
R1
47 kΩ
T1
C2
2.2 nF
1 KV
D2
1N5822
C3
270 µF
25 V
L1
3.3 µH
C4
100 µF
25 V
C1
10 nF
1 KV
D1
UF4005
D TOPSwitch-II
CONTROL
C
D3
1N4148
C6
100 µF
35 V
R3
U2
PC817A
75 Ω
R4
10 kΩ
R2
150 Ω
+
5 V – 2%
0.6 A
-
S TOP221P
U1
C C*
C5
CSS*
0.1 µF
47 µF
10 V
U3
TL431
R5
10 kΩ
* optional component, not populated
Figure 4. Schematic diagram of the RD7 with 12V Non-isolated output.
+
12 V
Non-isolated
50 mA
-
PI-2189-071098
measured with DC voltage applied to RD7.
Load Regulation (Figure 5(a) and 5(b)) - The amount of change
in the DC output voltage for a given change in output current is
referred to as load regulation. The 5 V output stay within
±1.0% when the output current is between 0% to 100% of rated
load current at the 5 V output. The TOPSwitch-II over-
temperature protection circuit will safely shut down the power
supply under prolonged overload conditions. When the output
load is disconnected, R3 acts as a preload and the output stays
in regulation.
Line Regulation (Figure 6(a) and 6(b)) - The amount of change
in DC output voltage for a given change in the DC input voltage
is called line regulation. The maximum change in output
voltage is within ±1%.
Efficiency (Line Dependent). Efficiency is the ratio of output
power to the input power. The curve in Figure 7 shows how the
efficiency changes with input voltage using a 3.5 W load. The
efficiency is greater than 72% throughout the input range.
Efficiency (Load Dependent). The curves in Figure 8 show
how the efficiency changes with output power at 155 and 310
VDC inputs. The efficiency is greater than 70% for loads
greater than 2.5 W.
Power Supply Turn On Sequence. An internal switched, high
voltage current source provides the initial bias current for
TOPSwitch when power is first applied. The waveforms shown
in Figure 8 illustrates the timing relationship between the high
voltage DC bus and 5 V output voltage for the RD7 circuit.
Capacitor C1 charges to the DC input voltage before TOPSwitch
turns on. The delay of 130 ms (typical) is caused by the time
required to charge the auto-restart capacitor C5 to 5.7 V. At this
point the power supply turns on as shown.
Figure 10 shows the output voltage turn on transient as well as
a family of curves associated with the additional soft-start
capacitor C . The soft-start capacitor is placed across VR2 and
ss
can range in value from 10 µF to 47 µF as shown.
Switching frequency ripple voltage is shown in Figure 11 for
the RD7 circuit at 155 VDC input and 3.5 W output. Peak to
peak ripple is less than 50 mV at 3.5 W.
The RD7 power supply transient response to a step load change
from 0.52 A to 0.75 A (75% to 100%) is shown in Figure 12.
The response is quick and well damped.
The RD7 is designed to meet worldwide safety specifications.
4
B
4/99
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