GE Industrial Solutions 12A Analog PicoDLynx - Manual (Page 14)

GE
Data Sheet
12A Analog PicoDLynx TM : Non-Isolated DC-DC Power Modules
3Vdc –14.4Vdc input; 0.6Vdc to 5.5Vdc output; 12A Output Current
August 13, 2013 ©2013 General Electric Corporation. All rights reserved. Page 14
( )
Ω






−
=
k
Vo
Rtrim
6 . 0
12
Rtrim is the external resistor in kΩ
Vo is the desired output voltage. Table 1 provides Rtrim
values required for some common output voltages.
Table 1
V
O, set
(V) Rtrim ( KΩ)
0.6 Open
0.9 40
1.0 30
1.2 20
1.5 13.33
1.8 10
2.5 6.316
3.3 4.444
5.0 2.727
Remote Sense
The power module has a Remote Sense feature to minimize
the effects of distribution losses by regulating the voltage at
the SENSE pin. The voltage between the SENSE pin and
VOUT pin should not exceed 0.5V.
Voltage Margining
Output voltage margining can be implemented in the
module by connecting a resistor, R
margin-up
, from the Trim pin
to the ground pin for margining-up the output voltage and
by connecting a resistor, R
margin-down
, from the Trim pin to
output pin for margining-down. Figure 43 shows the circuit
configuration for output voltage margining. The POL
Programming Tool, available at www.lineagepower.com
under the Downloads section, also calculates the values of
R
margin-up
and R
margin-down
for a specific output voltage and %
margin. Please consult your local GE technical
representative for additional details.
Figure 43. Circuit Configuration for margining Output
voltage.
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.
Overtemperature Protection
To provide protection in a fault condition, the unit is
equipped with a thermal shutdown circuit. The unit will
shutdown if the overtemperature threshold of 120(Q1) /
130(L1) o C(typ) is exceeded at the thermal reference point T
ref
. Once the unit goes into thermal shutdown it will then wait
to cool before attempting to restart.
Input Undervoltage Lockout
At input voltages below the input undervoltage lockout limit,
the module operation is disabled. The module will begin to
operate at an input voltage above the undervoltage lockout
turn-on threshold.
Power Good
The module provides a Power Good (PGOOD) signal that is
implemented with an open-drain output to indicate that the
output voltage is within the regulation limits of the power
module. The PGOOD signal will be de-asserted to a low state
if any condition such as overtemperature, overcurrent or
loss of regulation occurs that would result in the output
voltage going ±10% outside the setpoint value. The PGOOD
terminal can be connected through a pullup resistor
(suggested value 100KΩ) to a source of 5VDC or lower.
Dual Layout
Identical dimensions and pin layout of Analog and Digital
PicoDLynx modules permit migration from one to the other
without needing to change the layout. To support this, 2
separate Trim Resistor locations have to be provided in the
layout. For the digital modules, the resistor is connected
between the TRIM pad and SGND and in the case of the
analog module it is connected between TRIM and GND
Caution –
Do not connect SIG_GND to GND elsewhere in the
layout
Figure 44. Layout to support either Analog or Digital
PicoDLynx on the same pad.
Vo
MODULE
GND
Trim
Q1
Rtrim
Rmargin-up
Q2
Rmargin-down
MODULE
(PVX012 / PDT012) Rtrim1
for
Digital
GND (PIN 7)
SIG_GND
TRIM
Rtrim2
for
Analog