The high performance 14A UIS48T14050 DC-DC converter provides a high
efficiency single output, in a 1/16
th
brick package. Specifically designed for
operation in systems that have limited airflow and increased ambient
temperatures, the UIS48T14050 converter utilizes the same pinout and
Input/Output functionality of the industry-standard sixteenth bricks. In addition, a
baseplate / heat spreader feature is available (-xDxBx suffix) that provides an
effective thermal interface for coldplate and heat sinking options.
The UIS48T14050 converter thermal performance is accomplished through the
use advanced circuits, packaging, and processing techniques to achieve ultra-
high efficiency, excellent thermal management, and a low-body profile.
Operating from a wide-range 18-75V input, the UIS48T14050 converter utilizes
digital control and provides a fully regulated 5.0V output voltage. The designer
can expect reliability improvement over other available converters because of the
UIS48T14050’s optimized thermal efficiency.
Key Features & Benefits
Industry-standard sixteenth-brick pin-out
Ultra wide input voltage range
Delivers 70W at 90% efficiency
Paste In Hole (PIH) compatible
Withstands 100V input transient for 100ms
Fixed-frequency operation
On-board input differential LC-filter
Start-up into pre-biased load
No minimum load required
Minimum of 2,250V
DC
I/O isolation
Fully protected (OTP, OCP, OVP, UVLO)
Positive or negative logic ON/OFF option
Low height of 0.453” (11.5mm)
Weight: 18 g without baseplate / heat spreader,
24 g with baseplate / heat spreader
High reliability: MTBF = 14.3 million hours, calculated per Telcordia SR-332,
Method I Case 1
Approved to the latest edition of the following standards:
UL/CSA60950-1, IEC60950-1 and EN60950-1.
Designed to meet Class B conducted emissions per FCC and EN55022 when used
with external filter
All materials meet UL94, V-0 flammability rating
Applications
Intermediate Bus Architectures
Data communications/processing
LAN/WAN
Servers, storage, instrumentation, embedded equipment
2
UIS48T14050
1.
ELECTRICAL SPECIFICATIONS
Conditions: T
A
= 25 ºC, Airflow = 300 LFM (1.5 m/s), Vin = 48 VDC, Cin = 100 µF, unless otherwise specified.
PARAMETER
NOTES
Continuous
Transient (100ms)
Ambient (T
A
)
Component (T
C
)
1
MIN
-0.3
-40
-40
-55
TYP
MAX
80
100
85
125
125
UNITS
VDC
VDC
°C
°C
°C
VDC
VDC
VDC
MΩ
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Operating Temperature
(See Derating Curves)
Storage Temperature
ISOLATION CHARACTERISTICS
Input to Output
Isolation Voltage
Isolation Resistance
Isolation Capacitance
Input to Baseplate
Output to Baseplate
2250
1500
1500
10
-
330
Non-latching
Non-latching Component (T
C
)
1
pF
kHz
130
%
°C
ms
130
130
130
130
0.8
15
15
0.8
ms
ms
ms
ms
VDC
VDC
VDC
VDC
VDC
VDC
VDC
VDC
ADC
mA
mA
mA
PK-PK
mA
RMS
mA
PK-PK
mA
RMS
dB
FEATURE CHARACTERISTICS
Switching Frequency
Output Overvoltage Protection
Over Temperature Shutdown
Auto-Restart Period
Turn-On Time from Vin
Turn-On Time from ON/OFF Control
Turn-On Time from Vin
(w/ Co max.)
Turn-On Time from ON/OFF Control
(w/ Co max.)
ON/OFF Control (Positive Logic)
ON/OFF Control (Negative Logic)
115
125
130
500
100
100
100
100
-15
2.4
2.4
-15
18
16.8
14.9
0.5
Po = 70 W @ 18 VDC In
Vin = 48 V, converter disabled
Vin = 48V, converter enabled (No load on the output)
3
50
600
Vin = 48 V, 20 MHz bandwidth,
Po = 70 W (Figs. 14,15, 16)
Input Reflected-Ripple Current, i
S
Input Voltage Ripple Rejection
120 Hz
200
30
6
45
48
17.2
15.5
1.7
Applies to all protection features
Time from UVLO to Vo = 90% V
OUT
(
NOM
), Resistive load
Time from ON to Vo = 90% V
OUT
(
NOM
), Resistive load
Time from UVLO to Vo = 90% V
OUT
(
NOM
)
Resistive load, C
EXT
= 10000 µF load
Time from ON to Vo = 90% V
OUT
(
NOM
)
Resistive load, C
EXT
= 10000 µF load
Converter Off (logic low)
Converter On (logic high)
Converter Off (logic low)
Converter On (logic high)
INPUT CHARACTERISTICS
Operating Input Voltage Range
Input Undervoltage Lockout
Turn-on Threshold
Turn-off Threshold
Lockout Hysteresis Voltage
Maximum Input Current
Input Standby Current
Input No Load Current
Input Reflected-Ripple Current, ic
17.8
16.1
2.3
5
5
100
75
1
Reference Figure G for component T
C
locations.
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UIS48T14050
OUTPUT CHARACTERISTICS
Output Voltage Setpoint
Output Voltage Trim Range
Output Regulation
Over Line
Over Load
Output Voltage Range
Output Ripple and Noise
Admissible External Load Capacitance
Output Current Range
Current Limit Inception
RMS Short-Circuit Current
I
OUT
= 14 A, T
A
= 25°C
V
IN
= 48 V, T
A
= 25°C
Over line, load and temperature
20 MHz
bandwidth
C
EXT
=10 µF tantalum + 1 µF ceramic
C
EXT
=100 µF tantalum + 1 µF ceramic
C
EXT
ESR
0
16
18
2.9
4.85
±24
±24
5.0
50
25
±48
±48
5.15
100
50
4700
14
20
5
mV
mV
VDC
2
3
V
IN
= 48 V, I
OUT
= 0 A, T
A
= 25°C
Industry-std. equations
Percent of V
OUT
(
NOM
)
4.95
-20
5.00
5.05
+10
+10
VDC
%
%
Remote Sense Compensation
3
mV
PK-PK
µF
m
ADC
ADC
A
RMS
I
OUT
= 14 A (resistive)
Vin:18 V – 75 V
Non-latching
Non-latching Short = 10 mΩ
48V, 10μF Tan & 1μF Ceramic load cap, 0.1A/μs
25% Io.max to 50% Io.max
50% Io.max to 25% Io.max
to 2% of V
OUT
DYNAMIC RESPONSE
Output Voltage Current Transient
Positive Step Change in Output Current
Negative Step Change in Output Current
Settling Time
250
250
300
88
89
89
90
mV
mV
µs
EFFICIENCY
@ 60% Load
@ 100% Load
48V
IN
, T
A
= 25°C, 300LFM
%
2. ENVIRONMENT AND MECHANICAL SPECIFICATIONS
PARAMETER
NOTES
Non-condensing
Non-condensing
Without baseplate / heat spreader
With baseplate / heat spreader
GR-63-CORE, Sect. 5.4.2
Half Sinewave, 3-axis
Telcordia SR-332, Method I Case 1
50% electrical stress, 40°C components
CISPR 22 B with external EMI filter network
1
50
18
24
MIN
TYP
MAX
95
95
UNITS
%
%
g
g
g
g
ENVIRONMENTAL
Operating Humidity
Storage Humidity
MECHANICAL
Weight
Vibration
Shocks
RELIABILITY
MTBF
14.3
MHrs
EMI AND REGULATORY COMPLIANCE
Conducted Emissions
2
3
For input voltage >22 V
See
“Input Output Impedance”
, Page 4
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Europe, Middle East
+353 61 225 977
North America
+1 408 785 5200
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4
UIS48T14050
3. OPERATIONS
3.1. INPUT AND OUTPUT IMPEDANCE
These power converters have been designed to be stable with no external capacitors when used in low inductance
input and output circuits.
However, in some applications, the inductance associated with the distribution from the power source to the input of
the converter can affect the stability of the converter. A 100 µF electrolytic capacitor with adequate ESR based on input
impedance is recommended to ensure stability of the converter.
In many end applications, a high capacitance value is applied to the converter’s output via distributed capacitors. The
power converter will exhibit stable operation with external load capacitance up to 4700 µF.
3.2. ON/OFF (PIN 2)
The ON/OFF pin is used to turn the power converter on or off remotely via a system signal. There are two remote
control options available, positive and negative logic, with both referenced to Vin (-). A typical connection is shown in
Figure A.
The positive logic version turns on when the ON/OFF pin is at a logic high or left open and turns off when it is at a logic
low. See the Electrical Specifications for logic high/low definitions.
Fig. A: Typ. Circuit configuration for ON/OFF function.
UIS 48 Converter
(Top View )
Vin
ON /OFF
Vin (+)
Vout (+)
SENSE
(+)
Rload
TRIM
SENSE
(- )
Vin (-)
CONTROL
INPUT
Vout (-)
The negative logic version turns on when the ON/OFF pin is at a logic low and turns off when the pin is at logic high.
To enable automatic power up of the converter without the need of an external control signal the ON/OFF pin can be
hard wired directly to Vin (-) for N and left open for P version.
A properly de-bounced mechanical switch, open-collector transistor, or FET can be used to drive the input of the
ON/OFF pin. The device must be capable of sinking up to 0.2 mA at a low level voltage of
0.8 V. An external voltage
source (±15 V maximum) may be connected directly to the ON/OFF input, in which case it must be capable of sourcing
or sinking up to 1 mA depending on the signal polarity. If optocoupler is used to control the on/off, then the ON/OFF
pin should be tied to a 3V3 rail via 3.3kohm resistor to prevent optocoupler leakage from affecting the on/off function.
See the Startup Information section for system timing waveforms associated with use of the ON/OFF pin.
3.3. SENSE (PINS 5 AND 7)
The remote sense feature of the converter compensates for voltage drops occurring between the output pins of the
converter and the load. The SENSE (-) (Pin 5) and SENSE (+) (Pin 7) pins should be connected at the load or at the point
where regulation is required (see Fig. B).
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UIS48T14050
Fig. B: Remote sense circuit configuration.
UIS 48 Converter
(Top View )
SENSE
Vin
ON /OFF
Rw
5
Vin (+)
Vout (+)
100
(+)
Rload
TRIM
SENSE
( -)
10
Vin (- )
Vout (-)
Rw
CAUTION
If remote sensing is not utilized, the SENSE (-) pin must be connected to the Vout (-) pin (Pin 4), and the SENSE (+) pin
must be connected to the Vout (+) pin (Pin 8) to ensure the converter will regulate at the specified output voltage. If
these connections are not made, the converter will deliver an output voltage that is higher than the specified data sheet
value.
Because the sense leads carry minimal current, large traces on the end-user board are not required. However, sense
traces should be run side by side and located close to a ground plane to minimize system noise and ensure optimum
performance.
The converter’s output overvoltage protection (OVP) senses the voltage across Vout (+) and Vout (-), and not across
the sense lines, so the resistance (and resulting voltage drop) between the output pins of the converter and the load
should be minimized to prevent unwanted triggering of the OVP.
When utilizing the remote sense feature, care must be taken not to exceed the maximum allowable output power
capability of the converter, which is equal to the product of the nominal output voltage and the allowable output current
for the given conditions.
When using remote sense, the output voltage at the converter can be increased by as much as 10% above the nominal
rating in order to maintain the required voltage across the load. Therefore, the designer must, if necessary, decrease
the maximum current (originally obtained from the derating curves) by the same percentage to ensure the converter’s
actual output power remains at or below the maximum allowable output power.
3.4. OUTPUT VOLTAGE ADJUST /TRIM (PIN 6)
The output voltage can be adjusted up 10% or down 20%, relative to the rated output voltage by the addition of an
externally connected resistor.
The TRIM pin should be left open if trimming is not being used. To minimize noise pickup, a 0.1 µF capacitor is
connected internally between the TRIM and SENSE (-) pins.
To increase the output voltage, refer to Fig. C. A trim resistor, R
T-INCR
, should be connected between the TRIM (Pin 6)
and SENSE (+) (Pin 7), with a value of:
R
T-INCR
½
where,
5.11(100
Δ)V
O-NOM
- 626
10.22
kΩ
1.225Δ
R
T
INCR
½
Required value of trim-up resistor kΩ]
V
O
NOM
½
Nominal value of output voltage [V]
Δ
½
(V
O-REQ
V
O-NOM
)
X 100
V
O -NOM
[%]
Desired (trimmed) output voltage [V].
When trimming up, care must be taken not to exceed the converter‘s maximum allowable output power. See the
previous section for a complete discussion of this requirement.
V
O
REQ
½
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+353 61 225 977
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+1 408 785 5200
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