GE Industrial Solutions 16V PicoTLynx 4A - Manual (Page 16)

GE
Data Sheet
16V PicoTLynx TM 4A: Non-Isolated DC-DC Power Modules
8Vdc –16Vdc input; 0.6Vdc to 8.0Vdc output; 4A Output Current
September 10, 2013 ©2013 General Electric Company. All rights reserved. Page 16
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 140 o C is exceeded at the thermal
reference point T
ref
. The thermal shutdown is not intended as a
guarantee that the unit will survive temperatures beyond its
rating. 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.
Output Voltage Programming
The output voltage of the 16V PicoTLynx TM 4A modules can be
programmed to any voltage from 0.59dc to 8.0Vdc by
connecting a resistor between the Trim and GND pins of the
module. Certain restrictions apply on the output voltage set
point depending on the input voltage. These are shown in the
Output Voltage vs. Input Voltage Set Point Area plot in Fig. 56.
0
2
4
6
8
10
12
14
16
18
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8
Output Voltage (V)
In
p
u
t V
o
lt
a
g
e
(v
)
Figure 56. Output Voltage vs. Input Voltage Set Point Area
plot showing limits where the output voltage can be set for
different input voltages.
Without an external resistor between Trim and GND pins, the
output of the module will be 0.59Vdc. To calculate the value of
the trim resistor, Rtrim for a desired output voltage, use the
following equation:
( )
Ω






−
= k
Vo
Rtrim
591 . 0
91 . 5
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)
0.6 656.7
1.0 14.45
1.2 9.704
1.5 6.502
1.8 4.888
2.5 3.096
3.3 2.182
5.0 1.340
6.5 1.000
8.0 0.798
By using a ±0.5% tolerance trim resistor with a TC of ±100ppm,
a set point tolerance of ±1.5% can be achieved as specified in
the electrical specification.
Remote Sense
The 16V PicoTLynx TM 4A power modules have 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 must not exceed 0.5V. Note that
the output voltage of the module cannot exceed the specified
maximum value. This includes the voltage drop between the
SENSE and Vout pins. When the Remote Sense feature is not
being used, connect the SENSE pin to the VOUT pin.
V
O
(+)
TRIM
GND
R
trim
LOAD
V
IN
(+)
ON/OFF
SENSE
Figure 57. Circuit configuration for programming output
voltage using an external resistor.
Voltage Margining
Output voltage margining can be implemented in the 16V
PicoTLynx
TM 4A modules 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 10 shows the
circuit configuration for output voltage margining. The POL