GE Industrial Solutions Austin SuperLynx II 12V SMT - Manual (Page 12)

Data Sheet
October 1, 2009 Austin SuperLynx TM II 12V SMT Non-isolated Power Modules:
8.3 – 14Vdc Input; 0.75Vdc to 5.5Vdc Output;16A output current
LINEAGE POWER 12
Feature Description
Remote On/Off
Austin SuperLynx TM II 12V SMT power modules feature
an On/Off pin for remote On/Off operation. Two On/Off
logic options are available in the Austin SuperLynx
TM II
series modules. Positive Logic On/Off signal, device
code suffix “4”, turns the module ON during a logic High
on the On/Off pin and turns the module OFF during a
logic Low. Negative logic On/Off signal, no device code
suffix, turns the module OFF during logic High and turns
the module ON during logic Low.
For positive logic modules, the circuit configuration for
using the On/Off pin is shown in Figure 27. The On/Off
pin is an open collector/drain logic input signal (Von/Off)
that is referenced to ground. During a logic-high (On/Off
pin is pulled high internal to the module) when the
transistor Q1 is in the Off state, the power module is ON.
Maximum allowable leakage current of the transistor
when Von/off = V
IN,max
is 10µA. Applying a logic-low
when the transistor Q1 is turned-On, the power module
is OFF. During this state VOn/Off must be less than
0.3V. When not using positive logic On/off pin, leave the
pin unconnected or tie to V
IN.
Q1
R2
R1
Q2
R3
R4
Q3 CSS
GND
VIN+
ON/OFF
PWM Enable
+
_
ON/OFF
V
I
ON/OFF
MODULE
Figure 27. Circuit configuration for using positive
logic On/OFF.
For negative logic On/Off devices, the circuit
configuration is shown is Figure 28. The On/Off pin is
pulled high with an external pull-up resistor (typical R
pull-
up
= 68k, +/- 5%). When transistor Q1 is in the Off state,
logic High is applied to the On/Off pin and the power
module is Off. The minimum On/off voltage for logic
High on the On/Off pin is 2.5 Vdc. To turn the module
ON, logic Low is applied to the On/Off pin by turning ON
Q1. When not using the negative logic On/Off, leave
the pin unconnected or tie to GND.
Q1
R1
R2
Q2 CSS
GND
PWM Enable
ON/OFF
VIN+
ON/OFF
_
+
V
I
MODULE
pull-up
R
ON/OFF
Figure 28. Circuit configuration for using negative
logic On/OFF.
Overcurrent Protection
To provide protection in a fault (output overload)
condition, the unit is equipped with internal
current-limiting circuitry and can endure current
limiting continuously. At the point of current-limit
inception, the unit enters hiccup mode. The unit
operates normally once the output current is
brought back into its specified range. The typical
average output current during hiccup is 3A.
Input Undervoltage Lockout
At input voltages below the input undervoltage lockout
limit, module operation is disabled. The module will
begin to operate at an input voltage above the
undervoltage lockout turn-on threshold.
Overtemperature Protection
To provide protection in a fault condition, the unit is
equipped with a thermal shutdown circuit. The unit will
shutdown if the thermal reference point T
ref
, exceeds
125 o C (typical), but the thermal shutdown is not
intended as a guarantee that the unit will survive
temperatures beyond its rating. The module will
automatically restarts after it cools down.