SLIN-06E1AL BEL [Bel Fuse Inc.], SLIN-06E1AL Datasheet - Page 18

• Manufacturer Part Number: SLIN-06E1AL
• Description: NON-ISOLATED DC/DC CONVERTERS
• Manufacturer: BEL [Bel Fuse Inc.]

Output Voltage Sequencing (continued)
After applying input voltage to the module, a minimum 10msec delay is required before applying voltage on the
SEQ pin. This delay gives the module enough time to complete its internal power-up soft-start cycle. During the
delay time, the SEQ pin should be held close to ground (nominally 50mV ± 20 mV). This is required to keep the
internal op-amp out of saturation thus preventing output overshoot during the start of the sequencing ramp. By
selecting resistor R1 according to the following equation:
The voltage at the sequencing pin will be 50mV when the sequencing signal is at zero.
After the 10msec delay, an analog voltage is applied to the SEQ pin and the output voltage of the module will
track this voltage on a one-to-one volt basis until the output reaches the set-point voltage.
simultaneous shutdown of the modules, the SEQ pin voltage is lowered in a controlled manner. The output
voltage of the modules tracks the voltages below their set-point voltages on a one-to-one basis. A valid input
voltage must be maintained until the tracking and output voltages reach ground potential.
When using the sequencing feature to control start-up of the module, pre-bias immunity during start-up is
disabled. The pre-bias immunity feature of the module relies on the module being in the diode-mode during start-
up. When using the sequencing feature, modules goes through an internal set-up time of 10msec, and will be in
synchronous rectification mode when the voltage at the SEQ pin is applied. This will result in the module sinking
current if a pre-bias voltage is present at the output of the module. When pre-bias immunity during start-up is
required, the sequencing feature must be disabled.
please contact the Bel Power technical representative for additional information.
December 3, 2010
NON-ISOLATED DC/DC CONVERTERS
4.5 Vdc - 14 Vdc Input, 0.59 Vdc - 5.5 Vdc /6 A Outputs
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel [phone] • Fax [phone] •
Circuit showing connection of the sequencing signal to the SEQ pin
VIN+
GND
R1
SEQ
R
1
Bel Power, Inc. , a subsidiary of Bel Fuse, Inc.
=
499K
V
For additional guidelines on using the sequencing feature
IN
24950
10K
−
MODULE
. 0
05
+
-
ohms
OUT
www.belfuse.com
To initiate
18