UMP-5-5-Q12 C&D Technologies., UMP-5-5-Q12 Datasheet - Page 6

• Manufacturer Part Number: UMP-5-5-Q12
• Description: 25-40w, Single Output, Dc/dc Converters
• Manufacturer: C&D Technologies.

On/Off Control (Standard)
The On/Off Control pin (pin 5) may be used for remote on/off operation. As
shown in Figure 6, the control pin has an internal 10kΩ pull-up resistor to
approximately 10V. The converter is designed so that it is enabled when the
control pin is left open (normal mode) and disabled when the control pin is
pulled low (to less than +0.8V relative to –Input, pin 2).
Dynamic control of the on/off function is best accomplished with a mechani-
cal relay or an open-collector/open-drain drive circuit (optically isolated if
appropriate). The drive circuit should obviously be able to sink approximately
1mA when activated and withstand more than 10 Volts when deactivated.
Applying an external voltage to pin 5 when no input power is applied to the
converter can cause permanent damage to the converter. The on/off control
function, however, is designed such that the converter can be disabled (pin
5 pulled low) while input power is ramping up and then "released" once the
input has stabilized. Under these circumstances, it takes approximately 30ms
for the output of the fully loaded DC/DC to ramp up and settle to within ±1%
of its final value after the converter has been turned on.
Output Trimming
V
should be connected between +Output (pin 9) and Common (pin 8) with its
wiper connected to pin 10 (Trim). A trimpot can also be used to determine the
value of a single fixed resistor which can be connected between pin 10 (Trim)
and pin 9 (+Output) to trim "down" the output voltages, or between pins 10
(Trim) and 6 (–Output) to trim "up" the output voltages. Fixed resistors should
be metal-film types with absolute TCR's less than 100ppm/°C to ensure
stability.
Threaded Inserts and Heatsink Installation
CAUTION: Do not use the threaded inserts to bolt the converter down to a
PC board. That will place unnecessary force on the mounting pins. Instead,
the converter is held securely by only soldering the mounting pins.
When attaching the heat sink from above the converter, use a maximum
torque of 2 inch-pounds (0.23 N-m) on the 4-40 bolts to avoid damaging the
threaded inserts. Use a tiny amount of fastener adhesive or 4-40 lockwash-
ers to secure the bolts.
OUT
may be trimmed ±5% via a single trimpot or fixed resistor. The trimpot
Figure 6. Driving the On/Off Control Pin
3
5
2
+INPUT
ON/OFF
CONTROL
–INPUT
+10V
www.murata-ps.com
10k�
6
UMP Trim Resistor Equations
The equations listed below will set the output to a desired voltage using a
single fixed trim resistor if you do not prefer to use a potentiometer. Do not
exceed ±5% from the nominal output voltage. Trim resistors should have low
temperature coefficients, ±100ppm/°C or less to ensure stability. Adjustment
beyond the specified adjustment range is not recommended. Attach the trim
resistors as close as practical to the converter.
To trim the voltage higher than the nominal output, install the resistor be-
tween the trim pin and –V
To trim the voltage lower than the nominal output, install the resistor between
the trim pin and +V
These equations are a starting point. The final output voltage at the load will
vary slightly with load current, distance to the load (and voltage drop), input
voltage, ambient temperature, airflow, initial setpoint accuracy and several
other variables. For critical applications, you should measure the actual volt-
age obtained.
Case Connection
Unlike most other DC/DC converters, UMP DC/DC's do not have their metal
case connected to one of their input pins. The "uncommitted" case is con-
nected to pin 4 which, depending on your system configuration, should be
connected to either +Input (pin 3) or –Input (pin 2).
Figure 8. Trim Connections Using Fixed Resistors
Figure 7. Trim Connections Using a Trimpot
OUT
Technical enquiries email: [e-mail], tel:
terminal.
OUT
25-40W, Single Output, DC/DC Converters
terminal.
MDC_UMP25-40W_B01 Page 6 of 9
UMP Models
Note:
Install either a fixed
trim-up resistor
or a fixed trim-down
resistor depending upon
desired output voltage.
[phone]