Technical Specification
S25-48-3.3, S25-48-3.3N
Start up Information
Scenario #1: Initial Start up from power supply
BTCPower
48Vin 3.3Vout 7A
TM
On/Off function enabled, the unit starts via input
voltage Vin, see Fig 7
.
Time
t0
t1
t2
t3
Comments
On/Off pin is On: system front-end power is switched
on, Vin to unit begins to rise.
Vin crosses Under Voltage Lockout protection circuit
threshold: the unit enabled to be on
The unit begins to turn on ( unit turn-on delay).
Unit output voltage reaches 100% of normal
voltage.
For this example, the unit total start up time (t3- t1) is
typically 200us.
Scenario #2: Initial Start up using On/Off Pin
With Vin previously powered, the unit starts via
On/Off pin, see Fig 8
.
Time
t0
t1
t2
t3
Comments
Vin at nominal value.
Arbitrary time when On/Off pin is enabled (Unit
enabled)
End of unit turn-on delay
Unit Vout reaches 100% of nominal voltage.
Fig 7. Start up waveform
For this example, the unit total start up time (t3- t1) is
typically 300us.
Fig 8. Start up using On/Off pin
Broadband TelCom Power, Inc. –
1719 S. Grand Avenue, Santa Ana, CA 92705 U.S.A.
P 8 of 11
Tel.: 714-259-4888 • Fax: 714-259-0840 • www.btcpower.com • Email: sales@btcpower.com
PS S25-48-3.3 Rev 3 16-1-04