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®
®
INNOVATION and EXCELLENCE
Single Output
USQ 40A Models
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Model
High-Current, Quarter-Brick
40 Amp, DC/DC Converters
Features
To
40 Amperes Output Current
Low-profile, industry
standard
quarter-brick package and pinout;
1.45" x 2.28" x 0.40"
24V
and 48V nominal inputs
Output Voltages: 1.2/1.5/1.8/2.5/3.3V
Outstanding
Full
110mVp-p
Fast
efficiency: 89%
synchronous-rectifier topology
noise
transient response (200μsec to 1%)
Impressive
±0.05% line/load regulation
Fully
isolated, 1500Vdc guaranteed
Fully
I/O protected; Thermal shutdown
Remote
Output
On/Off control
trim and sense functions
UL1950/EN60950
approvals, HALT
tested, EMI compliant
An unrivaled combination of power, size, long-term reliability and affordable cost
defines DATEL’s new 40 Ampere output series Quarter-Bricks. By exploiting a fully
synchronous forward topology and the newest available components, the USQ 40A
model converters achieve an 89% efficiency. The extremely high efficiency enables
these units to reliably deliver up to 40 Amps of output power from a low-height
profile, industry-standard “quarter-brick” format package (1.45" x 2.28" x 0.40") with
aluminum baseplate and open-to-airflow shell. The USQ 40A models are a pincompatible, high-current, companion product family to DATEL’s USQ 30A and 20A
families, and the ULQ Series 10A and 15A family of quarter bricks.
Additional features include output noise of 110 millivolts, ±0.05% line/load regulation maximum, and quick transient response (200μsec to ±1%). Device functionality
includes remote on/off control (positive or negative polarity), and output trim (+10%,
–20%), sense function, and nominal input ranges of 24V (18-36V) and 48V (36-75V).
In order to safeguard both the power converter and its load, USQ 40A models,
offers the most extensive I/O protection including input undervoltage lockout, and
reverse-polarity protection, as well as output overvoltage protection, current limiting,
short-circuit protection (“hiccup” technique), and thermal shutdown (and optional
input overvoltage lockout).
The USQ 40A Series are designed to meet the BASIC insulation requirements of
UL1950 and EN60950. The “D48” models carry the CE mark. Safety certifications, as
well as EMC compliance testing and qualification testing (including HALT), have been
successfully completed. Contact DATEL for the latest information.
+SENSE
(7)
+VOUT
(8)
+VIN
(3)
SWITCH
CONTROL
–VOUT
(4)
–VIN
(1)
–SENSE
(5)
PWM
CONTROLLER
INPUT UNDERVOLTAGE, INPUT
OVERVOLTAGE, AND OUTPUT
OVERVOLTAGE COMPARATORS
REMOTE
ON/OFF
CONTROL*
(2)
OPTO
ISOLATION
REFERENCE &
ERROR AMP
VOUT
TRIM
(6)
* Can be ordered with positive (standard) or negative (optional) polarity.
Figure 1. Simplified Schematic
DATEL, Inc., Mansfield, MA 02048 (USA) · Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 · Email: [email protected] · Internet: www.datel.com
USQ Series
40A, SINGLE OUTPUT DC/DC CONVERTERS
Performance Specifications and Ordering Guide
➀
Input
Output
VOUT ➁
(Volts)
IOUT
(Amps)
Typ.
Max.
Line
Load ➃
VIN Nom.
(Volts) ➄
Efficiency
Package
(Case,
Pinout)
USQ-1.2/40-D24
1.2
40
90
110
±0.05%
±0
±0.05%
0.05%
244
18
18-36
83
2.4/3.5
80%
C33, P32
USQ-1.2/40-D48
1.2
40
80
110
±0.05%
±0
±0.05%
0.05%
488
36-75
366-75
1.23/1.76
82%
C33, P32
USQ-1.5/40-D24
1.5
40
110
TBD
±0.05%
±0
±0.05%
0.05%
05%
244
18-36
18
188--36
2.9/4.0
84%
C33, P32
Model
R/N (mVp-p) ➂
Regulation (Max.)
Range
(Volts) ➄
IIN ➅
(Amps)
USQ-1.5/40-D48
1.5
40
110
TBD
±0.05%
±0
±0.05%
0.05%
05%
4488
36
36-75
36-75
1.5/2.1
84%
C33, P32
USQ-1.8/40-D24
1.8
40
100
TBD
±0.05%
±0
±0.05%
0.05%
244
18-36
188-36
3.5/4.9
84%
C33, P32
USQ-1.8/40-D48
1.8
40
±0.05% a ±0
±0.05%
0.05%
05% n Model
4488 d 36-75
366-75
Contact
a 100Factory
c TBD for
o Replacement
1.8/2.5
84%
C33, P32
USQ-2.5/40-D24
2.5
40
145
TBD
±0.05%
±0
±0.05%
0.05%
244
18-36
188-36
4.7/7.0
88%
C33, P32
USQ-2.5/40-D48
2.5
40
145
TBD
±0.05%
±0
±0.05%
0.05%
488
36-75
366-75
2.4/3.3
88%
C33, P32
USQ-3.3/35-D24
3.3
35
155
TBD
±0.05%
±0.05%
24
18-36
5.4/7.5
89%
C33, P32
USQ-3.3/35-D48
3.3
35
155
TBD
±0.05%
±0.05%
48
36-75
2.8/3.9
89%
C33, P32
➃ The load-regulation specs apply over the 0-100% range. All models in the USQ Series have
no minimum-load requirements and will regulate within spec under no-load conditions (with
perhaps a slight increase in ripple/noise). Additionally, all models are unconditionally stable,
including start-up and short-circuit-shutdown situations, with capacitive loads up to 25,000μF.
➄ Contact DATEL for VIN ranges other than those listed.
➅ For each model, the two listed dc currents are for the following conditions: full load/nominal
input voltage and full load/low line voltage (36V). The latter is usually the worst-case condition
for input current.
➀ Typical at TA = +25°C under nominal line voltage and full-load conditions, unless otherwise
noted. All models are tested and specified with external output capacitors (1μF ceramic in
parallel with 10μF tantalum).
➁ Contact DATEL for fixed output voltages (such as 2V) other than those listed.
➂ Ripple/Noise (R/N) is tested/specified over a 20MHz bandwidth. Output noise may be further
reduced with the installation of additional external output filtering. See I/O Filtering, Input
Ripple Current, and Output Noise for details.
PA R T N U M B E R S T R U C T U R E
U SQ - 2.5 / 40 - D48 N D
Output Configuration:
U = Unipolar/Single
Negative Trim: Contact DATEL for "D" suffixed negative trim devices. See Technical Notes.
Remote On/Off Control Polarity: Add "P" for positive polarity (pin 2 open = converter on)
Add "N" for negative polarity (pin 2 open = converter off)
Input Voltage Range:
D48 = 36-75 Volts (48V nominal)
Quarter-Brick Package
Nominal Output Voltage:
1.2, 1.5, 1.8, 2.5 or 3.3 Volts
Note: Not all part number
combinations are available.
Contact DATEL.
Maximum Rated Output
Current in Amps
M E C H A N I C A L S P E C I F I C AT I O N S
2.28
(57.91)
Case C33
A
2.28 (57.91)
BAR CODE AND
SERIAL NUMBER
APPLIED TO
THIS SURFACE.
MODEL NUMBER ON
OPPOSITE SURFACE.
0.40 MAX.
(10.16)
PINS 1-3, 5-7:
0.040 ±0.001 (1.016 ±0.025)
PINS 4, 8:
0.062 ±0.001 (1.575 ±0.025)
Optional
Heat Sink
1.03
1.45
(26.16) (36.83)
0.15 MIN (3.81)
OPEN-FRAME, CAST
ALUMINUM CASE
2.00 (50.80)
A
1.860 (47.24)
A
0.140 DIA. (3.56) (4 PLACES)
2
3
0.300
(7.62)
4
(4) 0.170 DIA.
#M3 THD. THRU
WITH 0.090
THREAD RELIEF
5
6
7
8
BOTTOM VIEW
DIMENSIONS ARE IN INCHES (MM)
➀ DATEL conforms to industry-standard quarter-brick pinout (see Figure 15).
➁ A "baseplate only" model with a maximum height of 0.375" (9.53mm) is
available with the addition of an "H" suffix. Contact DATEL.
1.45 (36.83)
1
0.600
(15.24)
1.03 (26.16)
B
B
B
B
STANDOFF
0.015 (0.38)
1.860
(47.24)
0.600 (15.24)
4 EQ. SP. @
0.150 (3.81)
I/O Connections
Pin Function P32
1
–Input
2 Remote On/Off*
3
+Input
4
–Output
5
–Sense
6
Output Trim
7
+Sense
8
+Output
* The Remote On/Off
can be provided with
either positive (standard)
or negative (optional)
polarity.
2
*
MATERIAL: BLACK ANODIZED ALUMINUM
0.10
(2.54)
* USQ SERIES HEATSINKS ARE AVAILABLE IN 3 HEIGHTS:
0.25 (6.35), 0.50 (12.70) AND 1.00 (25.4)
Heat Sink Ordering Information
Heat Sink Height
0.25 inches (6.35mm)
0.50 inches (12.70mm)
1.00 inches (25.40mm)
DATEL Part Number
HS-QB25
HS-QB50
HS-QB100
All heat sinks include 4 mounting screws and a thermal pad.
If using heatsinks other than DATEL's HS-QB series, the screw length
should accomodate the 0.090 thread relief.
USQ Models
40A, SINGLE OUTPUT DC/DC CONVERTERS
Performance/Functional Specifications
Typical @ TA = +25°C under nominal line voltage and full-load conditions, unless noted.
Dynamic Characteristics
(1)
Dynamic Load Response (11)
See Dynamic Load Response
under Technical Notes
Input
Input Voltage Range:
D24 Models
D48 Models
18-36 Volts (24V nominal)
36-75 Volts (48V nominal)
Overvoltage Shutdown
None (3)
Start-Up Threshold:
D24 Models
D48 Models
Start-Up Time: (4) (12)
VIN to VOUT
On/Off to VOUT
5msec typical, 8msec maximum
5msec typical, 8msec maximum
Switching Frequency
(4)
(11)Environmental
14-16.5 Volts (15.3V nominal)
27-29.5 Volts (28.3V typical)
Calculated MTBF:
USQ-1.2/40-D24 -D48
USQ-1.5/40-D24 -D48
USQ-1.8/40-D24 -D48
USQ-2.5/40-D24 -D48
USQ-3.3/35-D24 -D48
See Ordering Guide
0.05A2 sec maximum
Operating Temperature (Ambient):
Without Derating
With Derating
(13)
15.5-18 Volts (16.5V nominal)
28.5-36 Volts (30V typical)
Undervoltage Shutdown: (4)
D24 Models
D48 Models
Input Current:
Normal Operating Conditions
Inrush Transient
Standby Mode:
Off, UV, Thermal Shutdown
Baseplate Temperature:
Maximum Allowable
Thermal Shutdown
4mA
Input Reflected Ripple Current (5)
6mAp-p
IInternal Input Filter Type:
D24 Models
D48 Models
Pi (0.01μF - 1.5μH - 3.3μF)
Pi (0.01μF - 4.7μH - 3.3μF)
Reverse-Polarity Protection (3)
1 minute duration, 5A maximum
>2.5 million hours
>2.5 million hours
>2.5 million hours
>2.5 million hours
>2.5 million hours
(4) (14)
Model and air flow dependent
To +110°C (baseplate)
(4) (14)
+110°C
+115-122°C, +118°C typical.
Physical
Remote On/Off Control (Pin 2): (6)
Positive Logic ("P" Suffix Models)
Dimensions
On = open, open collector or
2.5-5V applied. IIN = 150μA max.
Off = pulled low to 0-0.8V IIN = 800μA max.
On = pulled low to 0-0.8V IIN = 800μA max.
Off = open, open collector or
2.5-5V applied. IIN = 150μA max.
Negative Logic ("N" Suffix Models)
Case Material
Cast aluminum
Baseplate Material
Aluminum
Shielding
Neither the aluminum case nor baseplate
are connected to a package pin
Pin Material
Brass, solder coated
Weight:
1.52 ounces (43 grams)
Primary-to-Secondary Insulation Level Basic
(1)
Output
Minimum Loading
No load
Maximum Capacitive Loading (7)
25,000μF
VOUT Accuracy (Full Load):
Initial
Temperature Coefficient
Extreme (8)
±1% maximum
±0.02% per °C
±3%
((5)
VOUT Trim Range (9)
+10%, –20%
(6)
Remote Sense Compensation (4)
+10%
Ripple/Noise (20MHz BW)
See Ordering Guide
(7)
Line/Load Regulation
See Ordering Guide
(8)
Efficiency
See Ordering Guide
Isolation Voltage:
Input-to-Output
Input-to-Case
Output-to-Case
1500Vdc minimum
1500Vdc minimum
1500Vdc minimum
Isolation Resistance
100MΩ
(2)
(3)
(4)
(9)
(10)
Isolation Capacitance
650pF
Current Limit Inception (90% VOUT) (10)
50A typical
Short Circuit: (4)
Current
Duration
Hiccup
Continuous
Overvoltage Protection: (4)
1.2VOUT
1.5VOUT
1.8VOUT
2.5VOUT
Magnetic feedback
1.7 Volts
2.2 Volts
2.7 Volts
3.8 Volts
1.45" x 2.28" x 0.40" (36.8 x 57.9 x 10.2mm)
(11)
(12)
(13)
(14)
3
All models are tested and specified with external output capacitors (1μF ceramic in parallel
with 10μF tantalum) and, unless otherwise noted. These converters have no minimum-load
requirements and will effectively regulate under no-load conditions.
Contact DATEL for input voltage ranges other than those listed.
See Absolute Maximum Ratings for allowable input voltages.
See Technical Notes/Performance Curves for additional explanations and details.
Input Ripple Current is tested/specified over a 5-20MHz bandwidth with an external 33μF input
capacitor and a simulated source impedance of 220μF and 12μH. See I/O Filtering, Input
Ripple Current and Output Noise for details. The 24V input models can benefit by increasing the
33μF external input capacitance to 100μF, if the application has a high source impedance.
The On/Off Control is designed to be driven with open-collector (or equivalent) logic or the
application of appropriate voltages (referenced to –Input (pin 1). See Remote On/Off Control
for more details.
USQ Series DC/DC converters are unconditionally stable, including start-up and short-circuitshutdown situations, with capacitive loads up to 25,000μF.
Extreme Accuracy refers to the accuracy of either trimmed or untrimmed output voltages over
all normal operating ranges and combinations of input voltage, output load and temperature.
See Output Trimming for detailed trim equations.
The Current-Limit Inception point is the output current level at which the USQ’s power-limiting
circuitry drops the output voltage 10% from its initial value. See Output Current Limiting and
Short-Circuit Protection for more details.
See Dynamic Load Response under Technical Notes for detailed results including switching
frequencies. DATEL has performed extensive evaluations of Dynamic Load Response. In addi
tion to the 10μF || 1μF external capacitors, specifications are also given for 220μF || 1μF
external output capacitors for quick comparison purposes.
For the Start-Up Time specifications, output settling is defined by the output voltage having
reached ±1% of its final value.
MTBF’s are calculated using Telcordia SR-332 (Bellcore) Method 1 Case 3, ground fixed
conditions, +40°C case temperature, and full-load conditions. Contact DATEL for demonstrated
life-test data.
All models are fully operational and meet published specifications, including "cold start," at –40°C.
USQ Series
40A, SINGLE OUTPUT DC/DC CONVERTERS
impedance as highly inductive source impedance can affect system stability.
In Figure 2, CBUS and LBUS simulate a typical dc voltage bus. Your specific
system configuration may necessitate additional considerations.
Absolute Maximum Ratings
Input Voltage:
Continuous:
Transient (100msec)
24V models
39 Volts
50 Volts
48V models
81 Volts
100 Volts
Input Reverse-Polarity Protection
Input Current must be <5A. 1 minute
duration. Fusing recommended.
Output Current
Current limited. Devices can withstand
an indefinite output short circuit.
On/Off Control (Pin 2) Max. Voltages
Referenced to –Input (pin 1)
–0.3 to +7 Volts
Storage Temperature
–40 to +125°C
Lead Temperature (Soldering, 10 sec.)
+300°C
In critical applications, output ripple/noise (also referred to as periodic and
random deviations or PARD) can be reduced below specified limits using
filtering techniques, the simplest of which is the installation of additional
external output capacitors. Output capacitors function as true filter elements
and should be selected for bulk capacitance, low ESR, and appropriate
frequency response. In Figure 3, the two copper strips simulate real-world
pcb impedances between the power supply and its load. Scope measurements
should be made using BNC connectors or the probe ground should be less
than ½ inch and soldered directly to the fixture.
These are stress ratings. Exposure of devices to any of these conditions may adversely
affect long-term reliability. Proper operation under conditions other than those listed in the
Performance/Functional Specifications Table is not implied, nor recommended.
All external capacitors should have appropriate voltage ratings and be
located as close to the converter as possible. Temperature variations for all
relevant parameters should be taken into consideration. OS-CONTM organic
semiconductor capacitors (www.sanyo.com) can be especially effective for
further reduction of ripple/noise.
TECHNICAL NOTES
The most effective combination of external I/O capacitors will be a function
of line voltage and source impedance, as well as particular load and layout
conditions. Our Applications Engineers can recommend potential solutions
and discuss the possibility of our modifying a given device’s internal filtering
to meet your specific requirements. Contact our Applications Engineering
Group for additional details.
Removal of Soldered USQ's from PCB's
Should removal of the USQ from its soldered connection be needed, it is very
important to thoroughly de-solder the pins using solder wicks or de-soldering
tools. At no time should any prying or leverage be used to remove boards that
have not been properly de-soldered first.
Input Source Impedance
USQ converters must be driven from a low ac-impedance input source.
The DC/DC’s performance and stability can be compromised by the use of
highly inductive source impedances. The input circuit shown in Figure 2 is a
practical solution that can be used to minimize the effects of inductance in
the input traces. For optimum performance, components should be mounted
close to the DC/DC converter. The 24V models can benefit by increasing
the 33μF external input capacitors to 100μF, if the application has a high
source impedance.
+SENSE
+OUTPUT
VIN
CBUS
SCOPE
RLOAD
4
5
–SENSE
COPPER STRIP
C1 = 1μF CERAMIC
C2 = 10μF TANTALUM
LOAD 2-3 INCHES (51-76mm) FROM MODULE
Figure 3. Measuring Output Ripple/Noise (PARD)
Input Overvoltage Shutdown
3
+INPUT
Standard USQ DC/DC converters do not feature overvoltage shutdown.
They are equipped with this function, however. Many of our customers need
their devices to withstand brief input surges to 100V without shutting down.
Consequently, we disabled the function. Please contact us if you would like it
enabled, at any voltage, for your application.
LBUS
+
C2
–OUTPUT
All models in the USQ Series are tested/specified for input ripple current (also
called input reflected ripple current) and output noise using the circuits and
layout shown in Figures 2 and 3.
CURRENT
PROBE
COPPER STRIP
8
C1
I/O Filtering, Input Ripple Current, and Output Noise
TO
OSCILLOSCOPE
7
CIN
–
1
–INPUT
CIN = 33μF, ESR < 700mΩ @ 100kHz
CBUS = 220μF, ESR < 100mΩ @ 100kHz
LBUS = 12μH
Start-Up Threshold and Undervoltage Shutdown
Under normal start-up conditions, the USQ Series will not begin to regulate
properly until the ramping input voltage exceeds the Start-Up Threshold.
Once operating, devices will turn off when the applied voltage drops below
the Undervoltage Shutdown point. Devices will remain off as long as the
undervoltage condition continues. Units will automatically re-start when the
applied voltage is brought back above the Start-Up Threshold. The hysteresis built into this function avoids an indeterminate on/off condition at a single
input voltage. See Performance/Functional Specifications table for actual limits.
Figure 2. Measuring Input Ripple Current
External input capacitors (CIN in Figure 2) serve primarily as energy-storage
elements. They should be selected for bulk capacitance (at appropriate
frequencies), low ESR, and high rms-ripple-current ratings. The switching
nature of DC/DC converters requires that dc voltage sources have low ac
4
USQ Models
40A, SINGLE OUTPUT DC/DC CONVERTERS
of 5 to 15 milliseconds, the PWM will restart, causing the output voltages to begin
ramping to their appropriate values. If the short-circuit condition persists,
another shutdown cycle will be initiated. This on/off cycling is referred to
as “hiccup” mode. The hiccup cycling reduces the average output current,
thereby preventing internal temperatures from rising to excessive levels. The
USQ is capable of enduring an indefinite short circuit output condition.
Start-Up Time
The VIN to VOUT Start-Up Time is the interval between the point at which
a ramping input voltage crosses the Start-Up Threshold voltage and the
point at which the fully loaded output voltage enters and remains within it
specified ±1% accuracy band. Actual measured times will vary with input
source impedance, external input capacitance, and the slew rate and final
value of the input voltage as it appears to the converter.The On/Off to VOUT
Start-Up Time assumes the converter is turned off via the Remote On/Off
Control with the nominal input voltage already applied. The specification
defines the interval between the point at which the converter is turned on
(released) and the point at which the fully loaded output voltage enters and
remains within its specified ±1% accuracy band.
Thermal Shutdown
USQ converters are equipped with thermal-shutdown circuitry. If the internal
temperature of the DC/DC converter rises above the designed operating temperature (See Performance Specifications), a precision temperature sensor
will power down the unit. When the internal temperature decreases below
the threshold of the temperature sensor, the unit will self start.
On/Off Control
Output Overvoltage Protection
The primary-side, Remote On/Off Control function (pin 2) can be specified to
operate with either positive or negative polarity. Positive-polarity devices ("P"
suffix) are enabled when pin 2 is left open or is pulled high (+2.5-5V applied
with respect to –Input, pin 1, IIN < 150μA typical). Positive-polarity devices are
disabled when pin 2 is pulled low (0-0.8V with respect to –Input, IIN < 800μA.
Negative-polarity devices are off when pin 2 is high/open and on when pin 2
is pulled low. See Figure 4.
The output voltage is monitored for an overvoltage condition via magnetic
coupling to the primary side. If the output voltage rises to a fault condition,
which could be damaging to the load circuitry (see Performance Specifications), the sensing circuitry will power down the PWM controller causing
the output voltage to decrease. Following a time-out period the PWM will
restart, causing the output voltage to ramp to its appropriate value. If the
fault condition persists, and the output voltages again climb to excessive
levels, the overvoltage circuitry will initiate another shutdown cycle. This
on/off cycling is referred to as "hiccup" mode.
3
EQUIVALENT CIRCUIT FOR
POSITIVE AND NEGATIVE
LOGIC MODELS
+5V
+INPUT
Input Reverse-Polarity Protection
200k
If the input-voltage polarity is accidentally reversed, an internal diode will
become forward biased and likely draw excessive current from the power
source. If the source is not current limited (<5A) nor the circuit appropriately
fused, it could cause permanent damage to the converter.
2
ON/OFF
CONTROL
CONTROL
200k
REF
1
Input Fusing
–INPUT
Certain applications and/or safety agencies may require the installation of
fuses at the inputs of power conversion components. Fuses should also be
used if the possibility of a sustained, non-current-limited, input-voltage polarity reversal exists. For DATEL USQ Series DC/DCConverters, slow-blow
fuses are recommended with values no greater than the following:
Figure 4. Driving the Remote On/Off Control Pin
Dynamic control of the remote on/off function is best accomplished with
a mechanical relay or an open-collector/open-drain drive circuit (optically
isolated if appropriate). The drive circuit should be able to sink appropriate
current (see Performance Specifications) when activated and withstand
appropriate voltage when deactivated.
VOUT Range
1.2VOUT Models
1.5VOUT Models
1.8VOUT Models
2.5VOUT Models
3.3VOUT Models
Current Limiting
When power demands from the output falls within the current limit inception
range for the rated output current, the DC/DC converter will go into a current
limiting mode. In this condition the output voltage will decrease proportionately with increases in output current, thereby maintaining a somewhat
constant power dissipation. This is commonly referred to as power limiting.
Current limit inception is defined as the point where the full-power output
voltage falls below the specified tolerance. If the load current being drawn
from the converter is significant enough, the unit will go into a short circuit
condition. See “Short Circuit Condition.”
Fuse Value -D24
3.5 Amps
5 Amps
6 Amps
8 Amps
10 Amps
Fuse Value -D48
1.5 Amps
2.5 Amps
3 Amps
4 Amps
5 Amps
See Performance Specifications for Input Current and Inrush Transient limits.
Trimming Output Voltage
USQ converters have a trim capability (pin 6) that enables users to adjust
the output voltage from +10% to –20% (refer to the trim equations and trim
graphs that follow). Adjustments to the output voltage can be accomplished
with a single fixed resistor as shown in Figures 5 and 6. A single fixed resistor can increase or decrease the output voltage depending on its connection.
Resistors should be located close to the converter and have TCR's less than
100ppm/°C to minimize sensitivity to changes in temperature. If the trim
function is not used, leave the trim pin open.
Short Circuit Condition
When a converter is in current limit mode the output voltages will drop as
the output current demand increases. If the output voltage drops too low, the
magnetically coupled voltage used to develop primary side voltages will also
drop, thereby shutting down the PWM controller. Following a time-out period
5
USQ Series
40A, SINGLE OUTPUT DC/DC CONVERTERS
Standard USQ's have a "positive trim" where a single resistor connected from
the Trim Pin (pin 6) to the +Sense (pin 7) will increase the output voltage.
A resistor connected from the Trim pin (pin 6) to the –Sense (pin 5) will
decrease the output voltage. DATEL also offers a "negative trim" function (D
suffix added to the part number). Contact DATEL for information on negative
trim devices.
USQ-1.2/40-D24 -D48
RT UP (kΩ) =
RT UP (kΩ) =
RT UP (kΩ) =
6.23(VO – 1.226)
VO – 1.5
7.44(VO – 1.226)
VO – 1.8
10(VO – 1.226)
RT UP (kΩ) =
1.037
1.2 – VO
–1.413
–10.2
RTDOWN (kΩ) =
7.64
1.5 – VO
–10.2
–10.2
RTDOWN (kΩ) =
9.12
1.8 – VO
–10.2
VO – 2.5
–10.2
RTDOWN (kΩ) =
12.26
2.5 – VO
–10.2
USQ-3.3/35-D24 -D48
RT UP (kΩ) =
The Trim pin (pin 6) is a relatively high impedance node that can be susceptible to noise pickup when connected to long conductors in noisy environments. In such cases, a 0.22μF capacitor can be added to reduce this long
lead effect.
+SENSE
RTDOWN (kΩ) =
USQ-2.5/40-D24 -D48
(VOUT at pins) x (IOUT) ≤ rated output power
+OUTPUT
–1.413
USQ-1.8/40-D24 -D48
Temperature/power derating is based on maximum output current and voltage at the converter's output pins. Use of the trim and sense functions can
cause output voltages to increase, thereby increasing output power beyond
the USQ's specified rating, or cause output voltages to climb into the output
overvoltage region. Therefore:
–INPUT
VO – 1.2
USQ-1.5/40-D24 -D48
Trim adjustments greater than the specified +10%/–20% can have an
adverse affect on the converter’s performance and are not recommended.
Excessive voltage differences between VOUT and Sense, in conjunction with
trim adjustment of the output voltage, can cause the overvoltage protection
circuitry to activate (see Performance Specifications for overvoltage limits).
1
1.308(VO – 0.793)
13.3(VO – 1.226)
VO – 3.3
–10.2
RTDOWN (kΩ) =
16.31
3.3 – VO
–10.2
Note: Resistor values are in kΩ. Adjustment accuracy is subject to resistor
tolerances and factory-adjusted output accuracy. VO = desired output voltage.
8
Trim-Up Resistance vs. Percentage Increase
in Output Voltage
7
1 x 106
ON/OFF
CONTROL
6
TRIM
5
–SENSE
3
+INPUT
LOAD
RTRIM UP
4
–OUTPUT
1 x 105
RESISTANCE
2
Figure 5. Trim Connections To Increase Output Voltages Using Fixed Resistors
1 x 104
1
–INPUT
+OUTPUT
+SENSE
2
ON/OFF
CONTROL
TRIM
+INPUT
7
6
1 x103
LOAD
0
RTRIM DOWN
–SENSE
3
8
–OUTPUT
5
1
2
3
4
5
6
7
8
VOUT INCREASE (%)
Figure 7. USQ-1.2 Trim-Up Resistance vs. % Increase VOUT
4
Figure 6. Trim Connections To Decrease Output Voltages Using Fixed Resistors
6
9
10
USQ Models
40A, SINGLE OUTPUT DC/DC CONVERTERS
Trim-Up Resistance vs. Percentage Increase in Output Voltage
1
x 107
1 x 107
1 x 106
RESISTANCE
RESISTANCE
1 x 106
1 x 105
1 x 105
1 x104
1 x103
1 x104
0
1
2
3
4
5
6
7
8
9
10
0
1
2
3
VOUT INCREASE (%)
4
5
6
7
8
9
10
VOUT INCREASE (%)
Figure 8. USQ-1.5 Trim-Up Resistance vs. % Increase VOUT
Figure 9. USQ-1.8 Trim-Up Resistance vs. % Increase VOUT
1 x 106
1 x 106
RESISTANCE
1 x 107
RESISTANCE
1 x 107
1 x 105
1 x 105
1 x104
1 x104
0
1
2
3
4
5
6
7
8
9
10
0
1
2
3
4
VOUT INCREASE (%)
5
6
7
8
9
10
VOUT INCREASE (%)
Figure 11. USQ-3.3 Trim-Up Resistance vs. % Increase VOUT
Figure 10. USQ-2.5 Trim-Up Resistance vs. % Increase VOUT
Trim-Down Resistance vs. Percentage Decrease in Output Voltage
1 x 105
1 x 106
RESISTANCE
1 x 107
RESISTANCE
1 x 106
1 x 104
1 x 105
1 x103
1 x104
0
2
4
6
8
10
12
14
16
18
20
0
VOUT DECREASE (%)
2
4
6
8
10
12
14
16
18
VOUT DECREASE (%)
Figure 12. USQ-1.2 Trim-Down Resistance vs. % Decrease VOUT
Figure 13. USQ-1.5 to USQ-3.3 Trim-Down Resistance vs. % Decrease VOUT
7
20
USQ Series
40A, SINGLE OUTPUT DC/DC CONVERTERS
Negative-Trim Units ("D" Suffix)
Floating Outputs
Standard USQ's have a "positive-trim" function, consistent with the industry
standard footprints and functionality. DATEL also offers "negative-trim" USQ's
designated with a "D" suffix to the part number. The negative-trim devices
trim up with a single resistor tied from the Output Trim (pin 6) to the –Sense
(pin 5) to increase the output voltage. A resistor connected from the Output
Trim (pin 6) to the +Sense (pin 7) will decrease the ouput voltage.
Since these are isolated DC/DC converters, their outputs are "floating" with
respect to their input. Designers will normally use the –Output (pin 4) as the
ground/return of the load circuit. You can, however, use the +Output (pin 8) as
ground/return to effectively reverse the output polarity.
Remote Sense
Note: The Sense and VOUT lines are not internally connected to each other.
Therefore, if the sense function is not used for remote regulation, the user
must connect the +Sense to +VOUT and –Sense to –VOUT at the DC/DC
converter pins.
The "negative-trim" formula values for USQ 1.2/1.5/1.8 Volt devices with a
48 Volt input and negative logic reads:
RTRIM =
Model
USQ-1.8/40-D48ND
USQ-1.5/40-D48ND
USQ-1.2/40-D48ND
A – Bx ΔV
ΔV
Trim Up
A
0.57
0.283
0.5928
B
1
0.121
3.01
USQ series converters employ a sense feature to provide point-of-use regulation, thereby overcoming moderate IR drops in pcb conductors or cabling.
The remote sense lines carry very little current and therefore require a minimal cross-sectional area conductor. The sense lines, which are capacitively
coupled to their respective output lines, are used by the feedback control-loop
to regulate the output. As such, they are not low impedance points and must
be treated with care in layouts and cabling. Sense lines on a pcb should be
run adjacent to dc signals, preferably ground. In cables and discrete wiring
applications, twisted pair or other techniques should be implemented.
Trim Down
A
0.2711
0.065
0.5686
B
1.4676
0.352
3.96
where ΔV is the absolute value of the output voltage change desired.
USQ DC/DC converters will compensate for drops between the output
voltage at the DC/DC and the sense voltage at the DC/DC:
[VOUT(+) –VOUT(–)] – [Sense(+) –Sense (–)] ≤ 10% VOUT
1
–INPUT
+OUTPUT
+SENSE
Contact and PCB resistance
losses due to IR drops
8
7
IOUT
Sense Current
2
ON/OFF
CONTROL
TRIM
6
LOAD
Sense Return
–SENSE
5
IOUT Return
3
+INPUT
–OUTPUT
4
Contact and PCB resistance
losses due to IR drops
Figure 14. Remote Sense Circuit Configuration
Output overvoltage protection is monitored at the output voltage pin, not
the Sense pin. Therefore, excessive voltage differences between VOUT and
Sense, in conjunction with trim adjustment of the output voltage, can cause
the overvoltage protection circuitry to activate (see Performance Specifications for overvoltage limits). Power derating is based on maximum output
current and voltage at the converter’s output pins. Use of trim and sense
functions can cause output voltages to increase, thereby increasing output
power beyond the USQ’s specified rating, or cause output voltages to climb
into the output overvoltage region. Therefore:
(VOUT at pins) × (IOUT) ≤ rated output power
8
USQ Models
40A, SINGLE OUTPUT DC/DC CONVERTERS
To avoid the added cost of constantly changing test fixtures, we have verified, during our device characterization/verification testing, that 100% testing
under the former conditions (the 100μF || 1μF load), which we guarantee,
correlates extremely well with the latter conditions, for which we and most of
our competitors simply list typicals.
Dynamic Load Response and Switching Frequency
DATEL has performed extensive evaluations, under assorted capacitive-load
conditions, of the dynamic-load capabilities (i.e., the transient or step
response) of USQ Series DC/DC Converters. In particular, we have evaluated devices using the output capacitive-load conditions we use for our
routine production testing (10μF tantalums in parallel with 1μF ceramics), as
well as the load conditions many of our competitors use (220μF tantalums
in parallel with 1μF ceramics) when specifying the dynamic performance of
their devices.
Load Conditions ➀
COUT = 10μF || 1μF
COUT = 220μF || 1μF
If you have any questions about our test methods or would like us to perform
additional testing under your specific load conditions, please contact our
Applications Engineering Group.
Performance Specifications
1.2VOUT
1.5VOUT
1.8VOUT
2.5VOUT
3.3VOUT
Load Step = 50 to 75% of IOUT Max):
Peak Deviation typical
Settling Time to ±1% of Final Value, max. ➁
300mV
250μs
175mV
155μs
155mV
120μs
130mV
60μs
135mV
60μs
Load Step = 75 to 50% of IOUT Max.:
Peak Deviation typical
Settling Time to ±1% of Final Value, max. ➁
300mV
150μs
175mV
100μs
155mV
120μs
100mV
55μs
135mV
60μs
Load Step = 50 to 75% of IOUT Max.:
Peak Deviation typical
Settling Time to ±1% of Final Value, typ. ➁
220mV
130μs
165mV
150μs
85mV
150μs
125mV
55μs
130mV
55μs
Load Step = 75 to 50% of IOUT Max.:
Peak Deviation typical
Settling Time to ±1% of Final Value, typ. ➁
110mV
60μs
165mV
95μs
80mV
130μs
90mV
50μs
130mV
55μs
120/150/180
120/150/180
120/150/180
230/250/280
120/150/180
Switching Frequency (min./typ./max. kHz)
➀ The listed pair of parallel output capacitors consists of a tantalum in parallel with a multi-layer ceramic.
➁ ΔIO/Δt = 1A/1μs, VIN = 48V, TC = 25°C (±2% of final value for 1.2VOUT).
9
USQ Series
40A, SINGLE OUTPUT DC/DC CONVERTERS
Typical Performance Curves for 1.2VOUT Models
USQ-1.2/40-D48: Output Current vs. Ambient Temperature
(Longitudinal air flow, pin 1 to pin 3; VIN = 48V, 1/2" heat sink.)
USQ-1.2/40-D48 Efficiency vs. Line Voltage and Load Current
40
85
35
Output Current (Amps)
80
Efficiency (%)
75
VIN = 36V
70
65
VIN = 48V
60
30
600 lfm
25
400 lfm
20
200 lfm
15
10
55
VIN = 75V
5
50
4
8
12
16
20
24
28
32
36
0
–40
40
–10
0
10
20
30
40
50
60
Load Current (Amps)
Ambient Temperature (°C)
Start-Up from VIN
(VIN = 48V, IOUT = 40A, COUT = 10μF tantalum || 1μF ceramic.)
TBD
TBD
+Input (pin 3)
20V/div
1V/div
1.5VOUT (pin 8)
2msec/div
Start-Up from Remote On/Off Control
(VIN = 48V, IOUT = 40A, COUT = 10μF tantalum || 1μF ceramic.)
TBD
2V/div
TBD
Remote On/Off Control (pin 2)
1V/div
1.5VOUT (pin 8)
2msec/div
10
70
80
90
100
USQ Models
40A, SINGLE OUTPUT DC/DC CONVERTERS
Typical Performance Curves for 1.5VOUT Models
USQ-1.5/40-D48: Output Current vs. Ambient Temperature
(Transverse air flow, pin 1 to pin 3; VIN = 48V, no heat sink.)
USQ-1.5/40-D48 Efficiency vs. Line Voltage and Load Current
40
85
35
Output Current (Amps)
90
Efficiency (%)
80
VIN = 36V
75
70
VIN = 48V
65
60
VIN = 75V
30
600 lfm
25
400 lfm
20
200 lfm
15
Low LFM
10
55
5
50
4
8
12
16
20
24
28
Load Current (Amps)
32
36
0
–40
40
–10
0
10
20
30
40
50
60
70
80
90
100
80
90
100
Ambient Temperature (°C)
USQ-1.5/40-D48: Output Current vs. Ambient Temperature
(Longitudinal air flow, pin 1 to pin 3; VIN = 48V, 1/2" heat sink.)
Start-Up from VIN
(VIN = 48V, IOUT = 40A, COUT = 10μF tantalum || 1μF ceramic.)
40
35
Output Current (Amps)
+Input (pin 3)
20V/div
30
600 lfm
25
400 lfm
20
200 lfm
15
10
1V/div
1.5VOUT (pin 8)
5
0
–40
–10
0
10
20
30
40
50
60
2msec/div
Ambient Temperature (°C)
Start-Up from Remote On/Off Control
(VIN = 48V, IOUT = 40A, COUT = 10μF tantalum || 1μF ceramic.)
2V/div
Remote On/Off Control (pin 2)
1V/div
1.5VOUT (pin 8)
2msec/div
11
70
USQ Series
40A, SINGLE OUTPUT DC/DC CONVERTERS
Typical Performance Curves for 1.8VOUT Models
USQ-1.8/40-D48: Output Current vs. Ambient Temperature
(Transverse air flow, pin 1 to pin 3; VIN = 48V, no heat sink.)
USQ-1.8/40-D48 Efficiency vs. Line Voltage and Load Current
40
85
35
Output Current (Amps)
90
Efficiency (%)
80
75
VIN = 36V
70
65
VIN = 48V
60
30
600 lfm
25
400 lfm
20
200 lfm
15
Low LFM
10
VIN = 75V
55
5
50
4
8
12
16
20
24
28
32
36
0
–40
40
–10
0
10
20
30
40
50
60
70
80
90
100
80
90
100
80
90
100
Load Current (Amps)
Ambient Temperature (°C)
USQ-1.8/40-D48: Output Current vs. Ambient Temperature
(Transverse air flow, pin 1 to pin 3; VIN = 48V, 1/4" heat sink.)
Start-Up from VIN
(VIN = 48V, IOUT = 40A, COUT = 10μF tantalum || 1μF ceramic.)
40
35
Output Current (Amps)
+Input (pin 3)
20V/div
30
600 lfm
25
400 lfm
20
200 lfm
15
10
1V/div
1.8VOUT (pin 8)
5
0
–40
–10
0
10
2msec/div
20
30
40
50
60
70
Ambient Temperature (°C)
USQ-1.8/40-D48: Output Current vs. Ambient Temperature
(Longitudinal air flow, pin 1 to pin 3; VIN = 48V, 1/2" heat sink.)
Start-Up from Remote On/Off Control
(VIN = 48V, IOUT = 40A, COUT = 10μF tantalum || 1μF ceramic.)
40
2V/div
Remote On/Off Control (pin 2)
Output Current (Amps)
35
30
600 lfm
25
400 lfm
20
200 lfm
15
10
1V/div
1.8VOUT (pin 8)
5
0
–40
–10
0
10
20
30
40
50
60
2msec/div
Ambient Temperature (°C)
12
70
USQ Models
40A, SINGLE OUTPUT DC/DC CONVERTERS
Typical Performance Curves for 2.5VOUT Models
USQ-2.5/40-D48: Output Current vs. Ambient Temperature
(Transverse air flow, pin 1 to pin 3; VIN = 48V, no heat sink.)
USQ-2.5/40-D48 Efficiency vs. Line Voltage and Load Current
90
40
85
35
Output Current (Amps)
800 lfm
Efficiency (%)
80
75
VIN = 36V
70
VIN = 48V
65
60
30
600 lfm
25
400 lfm
20
200 lfm
15
Low LFM
10
VIN = 75V
55
5
50
4
8
12
16
20
24
28
32
36
0
–40
40
–10
0
10
Load Current (Amps)
20
30
40
50
60
70
80
90
100
80
90
100
Ambient Temperature (°C)
USQ-2.5/40-D48: Output Current vs. Ambient Temperature
(Longitudinal air flow, pin 1 to pin 3; VIN = 48V, 1/2" heat sink.)
Start-Up from VIN
(VIN = 48V, IOUT = 40A, COUT = 10μF tantalum || 1μF ceramic.)
40
35
Output Current (Amps)
+Input (pin 3)
20V/div
30
600 lfm
25
400 lfm
20
200 lfm
15
Low LFM
10
1V/div
2.5VOUT (pin 8)
5
0
–40
2msec/div
0
10
20
30
40
50
60
Ambient Temperature (°C)
Start-Up from Remote On/Off Control
(VIN = 48V, IOUT = 40A, COUT = 10μF tantalum || 1μF ceramic.)
2V/div
–10
Remote On/Off Control (pin 2)
1V/div
2.5VOUT (pin 8)
2msec/div
13
70
USQ Series
40A, SINGLE OUTPUT DC/DC CONVERTERS
Typical Performance Curves for 3.3VOUT Models
USQ-3.3/35-D48: Output Current vs. Ambient Temperature
(Transverse air flow, pin 1 to pin 3; VIN = 48V, no heat sink.)
USQ-3.3/35-D48 Efficiency vs. Line Voltage and Load Current
95
40
90
35
Output Current (Amps)
85
Efficiency (%)
80
75
VIN = 36V
70
65
VIN = 48V
60
30
600 lfm
25
400 lfm
20
200 lfm
15
Low LFM
10
55
VIN = 75V
5
50
45
3.5
7
10.5
14
17.5
21
24.5
28
31.5
0
–40
35
–10
0
10
20
Load Current (Amps)
30
40
50
60
70
80
90
100
80
90
100
Ambient Temperature (°C)
USQ-3.3/35-D48: Output Current vs. Ambient Temperature
(Transverse air flow, pin 1 to pin 3; VIN = 48V, 1/4" heat sink.)
Start-Up from VIN
(VIN = 48V, IOUT = 35A, COUT = 10μF tantalum || 1μF ceramic.)
40
35
Output Current (Amps)
+Input (pin 3)
20V/div
3.3VOUT (pin 8)
30
600 lfm
25
400 lfm
20
200 lfm
15
10
1V/div
5
0
–40
2msec/div
0
10
20
30
40
50
60
Ambient Temperature (°C)
Start-Up from Remote On/Off Control
(VIN = 48V, IOUT = 35A, COUT = 10μF tantalum || 1μF ceramic.)
2V/div
–10
Remote On/Off Control (pin 2)
3.3VOUT (pin 8)
1V/div
2msec/div
14
70
USQ Models
40A, SINGLE OUTPUT DC/DC CONVERTERS
+Input
Remote
On/Off
–Input
–Input
+Output
X
+Sense
Output Trim
LOCATE
THERMOCOUPLE
HERE
Remote On/Off
–Sense
Output Trim
+Sense
–Sense
+Input
–Output
+Output
BOTTOM VIEW
TOP VIEW
Figure 15.Thermocouple Placement for Temperature Derating Calculations
Figure 16. Industry Standard Quarter-Brick Pinout
The typical derating curves on the previous pages were developed by monitoring the temperature of the case with a thermocouple placed on top of
the USQ case as shown in Figure 15. Users desiring to model their own
application's temperature derating for a particular environment (enclosed
area, orientation, airflow, possible heatsinking) should make sure the case
temperature does not exceed 110°C for any condition.
®
–Output
Figure 16 readily allows users to confirm that DATEL quarter-brick DC/DC
converters are compatible to the industry-standard pinout, independent of
pin-numbering conventions.
®
INNOVATION and EXCELLENCE
ISO 9001 REGISTERED
DS-0510A
12/03
DATEL (UK) LTD. Tadley, England Tel: (01256)-880444
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 01-34-60-01-01
DATEL GmbH München, Germany Tel: 89-544334-0
DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-6354-2025
DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
Internet: www.datel.com
Email: [email protected]
DATEL makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein
do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.
15
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