ULQ-1.5/25-D48NM-C Murata Power Solutions Inc, ULQ-1.5/25-D48NM-C Datasheet - Page 8

• Manufacturer Part Number: ULQ-1.5/25-D48NM-C
• Description: DC/DC Converters & Regulators 37.5W 48Vto1.5V 25A NEG SURFACE MOUNT
• Manufacturer: Murata Power Solutions Inc
• Series: ULQr

Specifications of ULQ-1.5/25-D48NM-C

• Product: Isolated
• Output Power: 38 W
• Input Voltage Range: 36 V to 75 V
• Input Voltage (nominal): 48 V
• Number Of Outputs: 1
• Output Voltage (channel 1): 1.5 V
• Output Current (channel 1): 25 A
• Isolation Voltage: 2.25 KV
• Package / Case Size: Quarter Brick
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: ULQ-1.5/25-D48NM-C

On/Off Control ("P" or "N" suffi x)
The input-side, remote On/Off Control function (pin 2) can be ordered to
operate with either polarity:
"P" suffi x: Standard models are equipped with Positive-polarity and these
devices are enabled when pin 2 is left open (or is pulled high, applying +3.5V
to +13 with respect to –Input, pin 1) as per Figure 8. Positive-polarity devices
are disabled when pin 2 is pulled low (0 to 0.8V with respect to –Input).
"N" suffi x: Optional Negative-polarity devices are off when pin 2 is left open
(or pulled high, applying +3.5V to +13V), and on when pin 2 is pulled low (0 to
0.8V) with respect to –Input as shown in Figure 9.
Surface-Mount Package ("M" suffi x)
DATEL's ULQ series SMT DC/DC converters are the only higher-power (to
66W) DC/DC's that can be automatically "pick-and-placed" using standard
vacuum-pickup equipment and subsequently refl owed using high-tempera-
ture, lead-free solder.
Virtually all SMT DC/DC's today are unprotected "open-frame" devices
assembled by their vendors with high-temperature solder (usually
Sn96.5/Ag3.5 with a melting point +221°C) so that you may attach them
to your board using low-temperature solder (usually Sn63/Pb37 with a melt-
ing point of +183°C). Conceptually straightforward, this "stepped" solder
approach has its limitations . . . and is clearly out of step with an industry
trending toward the broad use of lead-free solders. No need to experiment
and develop refl ow profi les that ensure the components on their DC/DC never
exceed 215-216°C. If those components get too hot, "double-refl ow" could
compromise the reliability of their solder joints. Virtually all these devices
demand you "cool down" the Sn63 profi le you are likely using today.
Figure 8. Driving the Positive Polarity On/Off Control Pin
3
2
1
+INPUT
ON/OFF
CONTROL
–INPUT
Figure 10. ULQ SMT DC/DC
With Disposable Heat Shield
13V CIRCUIT
5V CIRCUIT
www.murata-ps.com
250
200
150
100
50
(When The Heat-shield Temperature Exceeds +250°C, The Air Within Is 50°C Cooler)
Z1
100
Dynamic control of the remote on/off function is best accomplished with
a mechanical relay or an open-collector/open-drain drive circuit (optically iso-
lated if appropriate). The drive circuit should be able to sink appropriate cur-
rent (see Performance Specifi cations) when activated and withstand appro-
priate voltage when deactivated. Applying an external voltage to pin 2 when
no input power is applied to the converter can cause permanent damage
to the converter.
DATEL is not exempted from the Laws of Physics. And we do not have
magic solders no one else has. Nevertheless, we have a simple and practical,
straightforward approach that works. We assemble our SMT DC/DC's on a
hightemperature, plastic lead-frame (nylon 46, UL94V-0 rated) using a high-
temperature (+216°C), lead-free alloy (Sn96.2%, Ag2.5%, Cu0.8%, Sb0.5%).
The lead-frame ensures coplanarity (to within 0.004 in.) of the unit's tin-plated
(150 microinches) copper leads and also supports a removable heat shield.
The disposable heat shield, which has a cutaway exposing the package
leads, provides thermal insulation to internal components during refl ow and
also doubles as the vacuum pick-up location. The insulation properties of the
heat shield are so effective that temperature differentials as high as 50°C
develop inside-to-outside the shield. Oven temperature profi les with peaks of
250-260°C and dwell times exceeding 2 minutes above 221°C (the melting
point of Sn96.5/Ag3.5) are easily achieved. DATEL's new-generation SMT
units are shipped in stackable, JEDEC-style plastic.
Z2
Z3
Figure 9. Driving the Negative Polarity On/Off Control Pin
200
Z4
Figure 11. Recommended Solder Profi le
Single Output, Low-Profi le, Quarter-Brick
3
2
1
Z5
+INPUT
ON/OFF
CONTROL
–INPUT
8-25 Amp Isolated DC/DC Converters
Z6
300
Z7
Seconds
21 Feb 2011 MDC_ULQ-15A.B03 Page 8 of 16
400
ULQ Models
email: [e-mail]
500
+V
CC
Heat Shield
Test Board
Air Under Shield
600