Q2D25ZGE-8C3
| Model | Q2D25ZGE-8C3 |
| Description | 2-OUTPUT DC-DC REG PWR SUPPLY MODULE |
| PDF file | Total 13 pages (File size: 196K) |
| Chip Manufacturer | BEL |
Q2D Series – Quarter-Brick DC/DC Converter
48V Input
Dual Output
Start-up Information (using negative
ON/OFF)
Scenario #1: Initial Start-up From Bulk Supply
ON/OFF function enabled, converter started via
application of V
IN
. See Figure 1.
Time
Comments
t
0
ON/OFF pin is ON; system front end power
is toggled on, V
IN
to converter begins to rise.
t
1
V
IN
crosses
Under-Voltage
Lockout
protection circuit threshold; converter
enabled.
t
2
Converter begins to respond to turn-on
command (converter turn-on delay).
t
3
Output voltage V
OUT
1 reaches 100% of
nominal value.
t
4
Output voltage V
OUT
2 reaches 100% of
nominal value.
For this example, the total converter start-up time (t
4
- t
1
)
is typically 3 ms.
t
4
t
5
Data Sheet
End of converter turn-on delay.
Output voltage V
OUT
1 reaches 100% of
nominal value.
t
6
Output voltage V
OUT
2 reaches 100% of
nominal value.
For the condition,
(t
2
- t
1
)
≤
100 ms,
the total converter
start-up time (t
6
- t
2
) is typically 103 ms. For
(t
2
- t
1
) >
100 ms,
start-up time will be typically 3 ms after release
of ON/OFF pin.
V
IN
ON/OFF
STATE
OFF
ON
V
OUT
2
V
OUT
1
V
OUT
2
V
OUT
1
Scenario #2: Initial Start-up Using ON/OFF Pin
With V
IN
previously powered, converter started via
ON/OFF pin. See Figure 2.
Time
Comments
t
0
V
INPUT
at nominal value.
t
1
Arbitrary time when ON/OFF pin is enabled
(converter enabled).
t
2
End of converter turn-on delay.
t
3
Output voltage V
OUT
1 reaches 100% of
nominal value.
t
4
Output voltage V
OUT
2 reaches 100% of
nominal value.
For this example, the total converter start-up time (t
4
-
t
1
) is typically 3 ms.
Scenario #3: Turn-off and Restart Using ON/OFF
Pin
With V
IN
previously powered, converter is disabled and
then enabled via ON/OFF pin. See Figure 3.
Time
Comments
t
0
V
IN
and V
OUT
are at nominal values; ON/OFF
pin ON.
t
1
ON/OFF pin arbitrarily disabled; converter
outputs fall to zero; turn-on inhibit delay
period (100 ms typical) is initiated, and
ON/OFF pin action is internally inhibited.
t
2
ON/OFF pin is externally re-enabled.
If (t
2
- t
1
)
≤
100 ms,
external action of
ON/OFF pin is locked out by start-up
inhibit timer.
If (t
2
- t
1
) > 100 ms,
ON/OFF pin action is
internally enabled.
t
3
Turn-on inhibit delay period ends. If ON/OFF
pin is ON, converter begins turn-on; if off,
converter awaits ON/OFF pin ON signal; see
Figure 6.
t
0
t
1
t
2
t
3
t
4
Fig. 1:
Start-up Scenario #1.
V
IN
ON/OFF
STATE OFF
ON
V
OUT
2
V
OUT
1
V
OUT
2
V
OUT
1
t
0
t
1
t
2
t
3
t
4
Fig. 2:
Start-up Scenario #2.
V
IN
ON/OFF
STATE OFF
100 ms
ON
V
OUT
2
V
OUT
1
V
OUT
2
V
OUT
1
t
0
t
1
t
2
t
3
t
4
t
5
t
6
Fig. 3:
Start-up Scenario #3.
Rev. JUN 06, 2002
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