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

Data Sheet
September 10, 2013 Austin Superlynx TM II SMT Non-isolated Power Modules:
2.4 – 5.5Vdc input; 0.75Vdc to 3.63Vdc Output; 16A output current
LINEAGE POWER 12
Feature Description
Remote On/Off
Austin SuperLynx TM II 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 28. 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 28. Remote On/Off Implementation.
For negative logic On/Off devices, the circuit
configuration is shown is Figure 29. The On/Off pin is
pulled high with an external pull-up resistor (typical Rpull-
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 1.5Vdc. 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 29. 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 3.5A.
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 over temperature protection in a fault
condition, the unit relies upon the thermal protection
feature of the controller IC. 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 restart after it cools down.