GE Industrial Solutions Austin MicroLynx II 12V SIP - Manual (Page 12)

Data Sheet
January 18, 2010
Austin MicroLynx II TM 12V SIP Non-isolated Power Modules:
8.3 – 14Vdc input; 0.75Vdc to 5.5Vdc Output; 6A output current
LINEAGE POWER 12
Feature Description
Remote On/Off
Austin MicroLynx TM II 12V SIP power modules
feature an On/Off pin for remote On/Off operation.
Two On/Off logic options are available in the Austin
MicroLynx
TM II 12V 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. Circuit configuration for using positive
logic On/OFF.
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
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 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 2A.
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
ref2
, (see Figure 33)
exceeds 140 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.