SQ48 Power-One, SQ48 Datasheet - Page 7

• Manufacturer Part Number: SQ48
• Description: Sq48 Dc-dc Series
• Manufacturer: Power-One

Startup Information (using negative ON/OFF)
Scenario #1: Initial Startup From Bulk Supply
ON/OFF function enabled, converter started via application
of V
For this example, the total converter startup time (t
typically 4 ms.
Scenario #2: Initial Startup Using ON/OFF Pin
With V
ON/OFF pin. See Figure G.
For this example, the total converter startup time (t
typically 4 ms.
Scenario #3: Turn-off and Restart Using ON/OFF Pin
With V
then enabled via ON/OFF pin. See Figure H.
For the condition, (t
startup time (t
startup will be typically 4 ms after release of ON/OFF pin.
SEP 14, 2005 revised to NOV 06, 2006
Time
Time
Time
t
t
t
t
t
t
t
t
t
t
t
t
t
t
0
1
2
3
4
5
IN
0
1
2
3
0
1
2
3
. See Figure F.
IN
IN
previously powered, converter started via
previously powered, converter is disabled and
V
ON.
ON/OFF pin arbitrarily disabled; converter output
falls to zero; turn-on inhibit delay period (100 ms
typical) is initiated, and ON/OFF pin action is
internally inhibited.
ON/OFF pin is externally re-enabled.
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 G.
End of converter turn-on delay.
Converter V
ON/OFF pin is ON; system front end power is
toggled on, V
V
circuit threshold; converter enabled.
Converter begins to respond to turn-on
command (converter turn-on delay).
Converter V
V
Arbitrary time when ON/OFF pin is enabled
(converter enabled).
End of converter turn-on delay.
Converter V
IN
IN
INPUT
5
and V
crosses Undervoltage Lockout protection
- t
If (t
ON/OFF pin is locked out by startup inhibit
timer.
If (t
internally enabled.
2
at nominal value.
) is typically 104 ms. For (t
2
2
2
- t
- t
OUT
- t
1
1
1
) ≤ 100 ms, external action of
) > 100 ms, ON/OFF pin action is
OUT
OUT
OUT
) ≤ 100 ms, the total converter
are at nominal values; ON/OFF pin
IN
to converter begins to rise.
reaches 100% of nominal value.
reaches 100% of nominal value.
reaches 100% of nominal value.
Comments
Comments
Comments
2
- t
1
) > 100 ms,
3
3
- t
- t
1
1
) is
) is
Page 7 of 64
36-75 VDC Input; 1.0-12 VDC Output
ON/OFF
STATE
ON/OFF
ON/OFF
V
STATE
STATE OFF
OUT
V
IN
V
V
OUT
OUT
V
V
t
0
IN
IN
OFF
SQ48 DC-DC Series Data Sheet
ON
t
0
OFF
ON
ON
t
1
t
2
t
3
Fig. G: Startup scenario #2.
Fig. H: Startup scenario #3.
Fig. F: Startup scenario #1.
t
1
t
0
t
2
t
1
100 ms
t
2
t
3
t
3
t
4
www.power-one.com
t
5
t
t
t