TM
SemiQ
SQM48 Series Data Sheet
Family 25A DC-DC Converters
The new 25A SemiQ™ Family of DC-DC converters provide
a high-efficiency single output in a size that is only 60% of
industry-standard quarter-bricks, while preserving the same
pinout and functionality.
The 25A SQM48 Series converters of the SemiQ™ Family
provide thermal performance in high temperature environments that exceeds most competitors' 25 A quarter-bricks.
This is accomplished through the use of patent pending circuit, packaging and processing techniques to achieve ultrahigh efficiency, excellent thermal management and a very
low body profile.
Low body profile and the preclusion of heatsinks minimize
airflow shadowing, thus enhancing cooling for downstream
devices. The use of 100% automation for assembly, coupled
with advanced electric and thermal design, results in a product with extremely high reliability.
Operating from a 36-75 V input, the 25A SQM48 Series
converters provide any standard output voltage from 2.5 V
down to 1.2 V. Outputs can be trimmed from –20% to +10%
of the nominal output voltage (±10% for output voltage 1.2
V), thus providing outstanding design flexibility.
With a standard pinout and trim equations, the SQM48
Series converters are perfect drop-in replacements for existing 25 A quarter-brick designs. Inclusion of this converter in
new designs can result in significant board space and cost
savings. The device is also available in a surface mount
package.
In both cases the designer can expect reliability improvement over other available converters because of the SQM48
Series’ optimized thermal efficiency.
Applications
Telecommunications
Data communications
Wireless
Servers
SQM48T and SQM48S Converters
Features
MCD10085 Rev. 1.1, 08-Jul-10
Page 1 of 30
RoHS lead-free solder and lead-solder-exempted
products are available
Delivers up to 25 A (62.5 W)
Industry-standard quarter-brick pinout
Extremely small footprint: 0.896” x 2.30” (2.06 in2),
40% smaller than conventional quarter-bricks
Higher current capability at elevated temperatures
than most competitors' 25 A quarter-bricks
On-board input differential LC-filter for the lowest input
ripple current in industry
Outputs available in 2.5, 2.0, 1.8, 1.5, and 1.2 V
High efficiency – no heatsink required
Start-up into pre-biased output
No minimum load required
Available in through-hole and SM packages
Low profile: 0.28” (7.1 mm)
Light weight: 0.66 oz (18.5 g)
Meets Basic Insulation requirements of EN60950
Withstands 100 V input transient for 100 ms
Fixed-frequency operation
Fully protected
Remote output sense
Output voltage trim range: +10%/−20% with Industrystandard trim equations (except 1.2 V output)
High reliability: MTBF of 3.4 million hours, calculated
per Telcordia TR-332, Method I Case 1
Positive or negative logic ON/OFF option
UL 60950 recognized in US and Canada and DEMKO
certified per IEC/EN 60950 (pending)
Meets conducted emissions requirements of FCC
Class B and EN 55022 Class B with external filter
All materials meet UL94, V-0 flammability rating
www.power-one.com
TM
SemiQ
SQM48 Series Data Sheet
Family 25A DC-DC Converters
Electrical Specifications (common to all versions)
Conditions: TA=25ºC, Airflow=300 LFM (1.5 m/s), Vin=48 Vdc, All output voltages, unless otherwise specified.
PARAMETER
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Operating Ambient Temperature
Storage Temperature
NOTES
Continuous
MIN
TYP
0
-40
-55
MAX
UNITS
80
85
125
Vdc
°C
°C
INPUT CHARACTERISTICS
Operating Input Voltage Range
Input Under Voltage Lockout
Turn-on Threshold
Turn-off Threshold
Input Voltage Transient
36
48
75
Vdc
33
31
34
32
35
33
100
Vdc
Vdc
Vdc
Non-latching
100 ms
ISOLATION CHARACTERISTICS
I/O Isolation
Isolation Capacitance
Isolation Resistance
2000
Vdc
pF
MΩ
160
10
FEATURE CHARACTERISTICS
Switching Frequency
1
Output Voltage Trim Range
435
1
Remote Sense Compensation
Output Over-Voltage Protection
Over-Temperature Shutdown (PCB)
Auto-Restart Period
Turn-On Time
ON/OFF Control (Positive Logic)
Converter Off
Converter On
ON/OFF Control (Negative Logic)
Converter Off
Industry-std. equations (2.5 - 1.5 V)
Use trim equation on Page 4 (1.2 V)
Percent of VOUT(NOM)
Non-latching
Non-latching
Applies to all protection features
-20
-10
117
122
125
100
3
+10
+10
+10
127
kHz
%
%
%
%
°C
ms
ms
-20
2.4
0.8
20
Vdc
Vdc
2.4
20
Vdc
Additional Notes:
1. Vout can be increased up to 10% via the sense leads or up to 10% via the trim function, however total output voltage trim from all sources
should not exceed 10% of VOUT(NOM), in order to insure specified operation of over-voltage protection circuitry.
MCD10085 Rev. 1.1, 08-Jul-10
Page 2 of 30
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TM
SemiQ
SQM48 Series Data Sheet
Family 25A DC-DC Converters
tion section for system timing waveforms associated with
use of the ON/OFF pin.
Operation
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 many applications, the inductance associated
with the distribution from the power source to the input of the
converter can affect the stability of the converter. The addition of a 33 µF electrolytic capacitor with an ESR < 1
across the input helps ensure stability of the converter. In
many applications, the user has to use decoupling capacitance at the load. The power converter will exhibit stable operation with external load capacitance up to 20,000 µF on
2.5 – 1.2 V outputs.
Remote 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).
SemiQ Family
Rw
TM
Vin (+)
Converter
(Top View)
Vin
ON/OFF
Vout (+)
100
SENSE (+)
TRIM
Rload
SENSE (-)
10
ON/OFF (Pin 2)
Vin (-)
Vout (+)
Rw
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 logic and negative logic and
both are referenced to Vin(-). Typical connections are shown
in Fig. A.
SemiQ Family
TM
Vin (+)
Converter
(Top View)
ON/OFF
Vin
Vout (+)
SENSE (+)
TRIM
Rload
SENSE (-)
Vin (-)
If remote sensing is not required, 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 slightly higher than the specified value.
Because the sense leads carry minimal current, large traces
on the end-user board are not required. However, sense
traces should be located close to a ground plane to minimize
system noise and insure optimum performance. When wiring
discretely, twisted pair wires should be used to connect the
sense lines to the load to reduce susceptibility to noise.
Vout (-)
CONTROL
INPUT
Fig. A: Circuit configuration for ON/OFF function.
The positive logic version turns on when the ON/OFF pin is
at logic high and turns off when at logic low. The converter is
on when the ON/OFF pin is left open.
The negative logic version turns on when the pin is at logic
low and turns off when the pin is at logic high. The ON/OFF
pin can be hard wired directly to Vin(-) to enable automatic
power up of the converter without the need of an external
control signal.
ON/OFF pin is internally pulled-up to 5 V through a resistor.
A 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 of ±20 V max.
may be connected directly to the ON/OFF input, in which
case it should be capable of sourcing or sinking (depending
on the signal polarity) up to 1 mA. See the Start-up Informa-
MCD10085 Rev. 1.1, 08-Jul-10
Fig. B: Remote sense circuit configuration.
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, 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
Page 3 of 30
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SemiQ
actual output power remains at or below the maximum allowable output power.
Output Voltage Adjust /TRIM (Pin 6)
The output voltage can be adjusted up 10% or down 20% for
Vout ≥ 1.5 V, and ±10% for Vout = 1.2 V 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, RT-INCR, should be connected between the TRIM (Pin 6)
and SENSE(+) (Pin 7), with a value of:
RTINCR
RTINCR
To decrease the output voltage (Fig. D), a trim resistor,
RT-DECR, should be connected between the TRIM (Pin 6) and
SENSE(-) (Pin 5), with a value of:
RTDECR
511
10.22 [k] (2.5 – 1.5 V)
Δ
RTDECR
700
15 [k] (1.2 V)
Δ
where,
RTDECR Required value of trim-down resistor [k]
and Δ is as defined above.
Note: The above equations for calculation of trim resistor
values match those typically used in conventional industrystandard quarter bricks.
5.11(100 Δ)VONOM 626
10.22 [k] (2.5 –1.5V)
1.225Δ
84.6
7.2 [k]
Δ
SQM48 Series Data Sheet
Family 25A DC-DC Converters
SemiQ Family
TM
Vin (+)
Converter
(Top View)
(1.2 V)
Vin
ON/OFF
Vout (+)
SENSE (+)
TRIM
SENSE (-)
Vin (-)
where,
RTINCR Required value of trim-up resistor k]
VONOM Nominal value of output voltage [V]
VOREQ Desired (trimmed) output voltage [V].
When trimming up, care must be taken not to exceed the
converter‘s maximum allowable output power. See previous
the section for a complete discussion of this requirement.
SemiQ Family
TM
Converter
(Top View)
Vin
ON/OFF
Vout (-)
Fig. D: Configuration for decreasing output voltage.
(VO-REQ VO-NOM)
Δ
X 100 [%]
VO -NOM
Vin (+)
Rload
R T-DECR
Trimming/sensing beyond 110% of the rated output voltage
is not an acceptable design practice, as this condition could
cause unwanted triggering of the output over-voltage protection (OVP) circuit. The designer should ensure that the difference between the voltages across the converter’s output
pins and its sense pins does not exceed 10% of VOUT(NOM),
or:
[VOUT() VOUT()] [VSENSE() VSENSE()] VO - NOM X 10% [V]
This equation is applicable for any condition of output sensing and/or output trim.
Vout (+)
SENSE (+)
R T-INCR
TRIM
Rload
SENSE (-)
Vin (-)
Vout (-)
Fig. C: Configuration for increasing output voltage.
MCD10085 Rev. 1.1, 08-Jul-10
Page 4 of 30
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TM
SemiQ
SQM48 Series Data Sheet
Family 25A DC-DC Converters
(pending). Basic Insulation is provided between input and
output.
Protection Features
Input Undervoltage Lockout
Input undervoltage lockout is standard with this converter.
The converter will shut down when the input voltage drops
below a pre-determined voltage.
To comply with safety agencies requirements, an input line
fuse must be used external to the converter. The Table below provides the recommended fuse rating for use with this
family of products.
The input voltage must be at least 35 V for the converter to
turn on. Once the converter has been turned on, it will shut
off when the input voltage drops below 31 V. This feature is
beneficial in preventing deep discharging of batteries used in
telecom applications.
Output Voltage
2.5 V
2.0 - 1.5 V
1.2 V
Fuse Rating
4-A
3-A
2.5-A
Modules are UL approved for maximum fuse rating of 15-A.
To protect a group of modules with a single fuse, the rating
can be increased from the recommended values above.
Output Overcurrent Protection (OCP)
The converter is protected against overcurrent or short circuit conditions. Upon sensing an overcurrent condition, the
converter will switch to constant current operation and thereby begin to reduce output voltage. When the output voltage
drops below 40-50% of the nominal value of output voltage,
the converter will shut down (Fig. x.11).
Once the converter has shut down, it will attempt to restart
nominally every 100 ms with a typical 1-2% duty cycle
(Fig. x.12). The attempted restart will continue indefinitely
until the overload or short circuit conditions are removed or
the output voltage rises above 40-50% of its nominal value.
Output Overvoltage Protection (OVP)
The converter will shut down if the output voltage across
Vout(+) (Pin 8) and Vout(-) (Pin 4) exceeds the threshold of
the OVP circuitry. The OVP circuitry contains its own reference, independent of the output voltage regulation loop.
Once the converter has shut down, it will attempt to restart
every 100 ms until the OVP condition is removed.
Electromagnetic Compatibility (EMC)
EMC requirements must be met at the end-product system
level, as no specific standards dedicated to EMC characteristics of board mounted component dc-dc converters exist.
However, Power-One tests its converters to several system
level standards, primary of which is the more stringent
EN55022, Information technology equipment - Radio disturbance characteristics - Limits and methods of measurement.
Effective internal LC differential filter significantly reduces
input reflected ripple current (Fig. x.9), and improves EMC.
With the addition of a simple external filter, all versions of the
SQM48 Series of converters pass the requirements of Class
B conducted emissions per EN55022 and FCC, and meet at
a minimum, Class A radiated emissions per EN 55022 and
Class B per FCC Title 47CFR, Part 15-J. Please contact
di/dt Applications Engineering for details of this testing.
Characterization
Overtemperature Protection (OTP)
General Information
The converter will shut down under an overtemperature condition to protect itself from overheating caused by operation
outside the thermal derating curves, or operation in abnormal conditions such as system fan failure. After the converter has cooled to a safe operating temperature, it will automatically restart.
The converter has been characterized for many operational
aspects, to include thermal derating (maximum load current
as a function of ambient temperature and airflow) for vertical
and horizontal mounting, efficiency, start-up and shutdown
parameters, output ripple and noise, transient response to
load step-change, overload and short circuit.
Safety Requirements
The converters meet North American and International safety regulatory requirements per UL60950 and EN60950
MCD10085 Rev. 1.1, 08-Jul-10
The figures are numbered as Fig. x.y, where x indicates the
different output voltages, and y associates with specific plots
(y = 1 for the vertical thermal derating, …). For example, Fig.
x.1 will refer to the vertical thermal derating for all the output
voltages in general.
Page 5 of 30
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SemiQ
The following pages contain specific plots or waveforms associated with the converter. Additional comments for specific
data are provided below.
Test Conditions
All data presented were taken with the converter soldered to
a test board, specifically a 0.060” thick printed wiring board
(PWB) with four layers. The top and bottom layers were not
metalized. The two inner layers, comprising two-ounce copper, were used to provide traces for connectivity to the converter.
The lack of metalization on the outer layers as well as the
limited thermal connection ensured that heat transfer from
the converter to the PWB was minimized. This provides a
worst-case but consistent scenario for thermal derating purposes.
All measurements requiring airflow were made in vertical
and horizontal wind tunnel facilities using Infrared (IR) thermography and thermocouples for thermometry.
Ensuring components on the converter do not exceed their
ratings is important to maintaining high reliability. If one anticipates operating the converter at or close to the maximum
loads specified in the derating curves, it is prudent to check
actual operating temperatures in the application. Thermographic imaging is preferable; if this capability is not available, then thermocouples may be used. Power-One recommends the use of AWG #40 gauge thermocouples to ensure
measurement accuracy. Careful routing of the thermocouple
leads will further minimize measurement error. Refer to Figure H for optimum measuring thermocouple location.
SQM48 Series Data Sheet
Family 25A DC-DC Converters
Efficiency
Efficiency vs. load current plot is shown in Fig. x.2 for ambient temperature of 25 ºC, airflow rate of 300 LFM (1.5 m/s),
vertical converter mounting, and input voltages of 36 V, 48 V
and 72 V.
Start-up
Output voltage waveforms, during the turn-on transient using
the ON/OFF pin for full rated load currents (resistive load)
are shown without and with external load capacitance in Fig.
x.3 and Fig. x.4, respectively.
Ripple and Noise
Fig. x.7 shows the output voltage ripple waveform, measured
at full rated load current with a 10 µF tantalum and 1 µF ceramic capacitor across the output. Note that all output voltage waveforms are measured across a 1 F ceramic capacitor.
The input reflected ripple current waveforms are obtained
using the test setup shown in Fig x.8. The corresponding
waveforms are shown in Fig. x.9 and Fig. x.10.
Thermal Derating
Load current vs. ambient temperature and airflow rates are
given in Fig. x.1 for through-hole version. Ambient temperature was varied between 25 °C and 85 °C, with airflow rates
from 30 to 500 LFM (0.15 to 2.5 m/s), and vertical converter
mounting.
For each set of conditions, the maximum load current was
defined as the lowest of:
(i) The output current at which either any FET junction temperature did not exceed a maximum specified temperature
(120°C) as indicated by the thermographic image, or
(ii) The nominal rating of the converter (25 A on 2.5 – 1.2 V).
During normal operation, derating curves with maximum FET
temperature less or equal to 120 °C should not be exceeded.
Temperature on the PCB at the thermocouple location
shown in Fig. H should not exceed 118 °C in order to operate inside the derating curves.
MCD10085 Rev. 1.1, 08-Jul-10
Page 6 of 30
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TM
SemiQ
SQM48 Series Data Sheet
Family 25A DC-DC Converters
V IN
Start-up Information (using negative ON/OFF)
Scenario #1: Initial Start-up From Bulk Supply
ON/OFF function enabled, converter started via application of VIN.
See Figure E.
Time
Comments
t0
ON/OFF pin is ON; system front end power is toggled
on, VIN to converter begins to rise.
t1
VIN crosses Under-Voltage Lockout protection circuit
threshold; converter enabled.
t2
Converter begins to respond to turn-on command
(converter turn-on delay).
t3
Converter VOUT reaches 100% of nominal value.
For this example, the total converter start-up time (t3- t1) is typically
3 ms.
ON/OFF
STATE
OFF
ON
V OUT
t0
t1 t2
t
t3
VIN
Scenario #2: Initial Start-up Using ON/OFF Pin
With VIN previously powered, converter started via ON/OFF pin.
See Figure F.
Time
Comments
t0
VINPUT at nominal value.
t1
Arbitrary time when ON/OFF pin is enabled (converter
enabled).
t2
End of converter turn-on delay.
t3
Converter VOUT reaches 100% of nominal value.
For this example, the total converter start-up time (t3- t1) is typically
3 ms.
Scenario #3: Turn-off and Restart Using ON/OFF Pin
With VIN previously powered, converter is disabled and then
enabled via ON/OFF pin. See Figure G.
Time
Comments
t0
VIN and VOUT are at nominal values; ON/OFF pin ON.
t1
ON/OFF pin arbitrarily disabled; converter output falls
to zero; turn-on inhibit delay period (100 ms typical) is
initiated, and ON/OFF pin action is internally inhibited.
t2
ON/OFF pin is externally re-enabled.
If (t2- t1) ≤ 100 ms, external action of ON/OFF pin
is locked out by start-up inhibit timer.
If (t2- t1) > 100 ms, ON/OFF pin action is internally
enabled.
t3
Turn-on inhibit delay period ends. If ON/OFF pin is ON,
converter begins turn-on; if off, converter awaits
ON/OFF pin ON signal; see Figure F.
t4
End of converter turn-on delay.
t5
Converter VOUT reaches 100% of nominal value.
For the condition, (t2- t1) ≤ 100 ms, the total converter start-up
time (t5- t2) is typically 103 ms. For (t2- t1) > 100 ms, start-up will
be typically 3 ms after release of ON/OFF pin.
ON/OFF
STATE OFF
ON
VOUT
t0
t1 t 2
t
t3
Fig. F: Start-up scenario #2.
VIN
100 ms
ON/OFF
STATE OFF
ON
VOUT
t0
t1
t2
t3 t4
t
t5
Fig. G: Start-up scenario #3.
Fig. E: Start-up scenario #1.
MCD10085 Rev. 1.1, 08-Jul-10
Page 7 of 30
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TM
SemiQ
SQM48 Series Data Sheet
Family 25A DC-DC Converters
Electrical Specifications: SQM48T/S25025 (2.5 Volts Out)
Conditions: TA=25ºC, Airflow=300 LFM (1.5 m/s), Vin=48 Vdc, Vout=2.5 Vdc unless otherwise specified.
PARAMETER
INPUT CHARACTERISTICS
NOTES
Maximum Input Current
Input Stand-by Current
Input No Load Current (0 load on the output)
Input Reflected-Ripple Current
Input Voltage Ripple Rejection
MIN
25 Adc, 2.5 Vdc Out @ 36 Vdc In
Vin = 48 V, converter disabled
Vin = 48 V, converter enabled
25MHz bandwidth
120Hz
TYP
MAX
UNITS
2.0
Adc
mAdc
mAdc
mAPK-PK
dB
2.500
2.525
Vdc
±2
±2
±5
±5
2.538
50
20,000
25
32
46
6.7
mV
mV
Vdc
mVPK-PK
μF
Adc
Adc
A
Arms
3
37
6
TBD
OUTPUT CHARACTERISTICS
Output Voltage Set Point (no load)
Output Regulation
Over Line
Over Load
Output Voltage Range
Output Ripple and Noise - 25MHz bandwidth
External Load Capacitance
Output Current Range
Current Limit Inception
Peak Short-Circuit Current
RMS Short-Circuit Current
-40ºC to 85ºC
2.475
Over line, load and temperature
Full load + 10 μF tantalum + 1 μF ceramic
Plus full load (resistive)
2.462
30
0
26.5
Non-latching
Non-latching. Short=10mΩ.
Non-latching
30
35
DYNAMIC RESPONSE
Load Change 20% of Iout Max, di/dt = 0.1 A/μS
di/dt = 5 A/μS
Setting Time to 1%
Co = 1 μF ceramic
Co = 450 μF tant. + 1 μF ceramic
80
140
100
mV
mV
µs
85.5
89
%
%
EFFICIENCY
30
0.95
25
0.90
20
0.85
Efficiency
Load Current [Adc]
100% Load
50% Load
15
500 LFM (2.5 m/s)
400 LFM (2.0 m/s)
300 LFM (1.5 m/s)
200 LFM (1.0 m/s)
100 LFM (0.5 m/s)
30 LFM (0.15 m/s)
10
5
0.80
0.75
72 V
48 V
36 V
0.70
0
0.65
20
30
40
50
60
70
80
90
0
Ambient Temperature [°C]
10
15
20
25
30
Load Current [Adc]
Fig. 2.5V.1: Available load current vs. ambient air temperature
and airflow rates for SQM48T25025 converter with D height
pins mounted vertically with air flowing from pin 3 to pin 1,
MOSFET temperature 120 C, Vin = 48 V.
MCD10085 Rev. 1.1, 08-Jul-10
5
Fig. 2.5V.2: Efficiency vs. load current and input voltage for
SQM48T/S25025 converter mounted vertically with air flowing
from pin 3 to pin 1 at a rate of 300 LFM (1.5 m/s) and
Ta = 25 C.
Page 8 of 30
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SemiQ
SQM48 Series Data Sheet
Family 25A DC-DC Converters
SQM48T/S25025 (2.5 Volts Out)
Fig. 2.5V.3: Turn-on transient at full rated load current (resistive) with no output capacitor at Vin = 48 V, triggered via
ON/OFF pin. Top trace: ON/OFF signal (5 V/div.). Bottom
trace: output voltage (1 V/div.). Time scale: 1 ms/div.
Fig. 2.5V.4: Turn-on transient at full rated load current (resistive) plus 20,000 F at Vin = 48 V, triggered via ON/OFF pin.
Top trace: ON/OFF signal (5 V/div.). Bottom trace: output voltage (1 V/div.). Time scale: 2 ms/div.
Fig. 2.5V.5: Output voltage response to load current stepchange (5 A – 10 A – 5 A) at Vin = 48 V. Top trace: output voltage (100 mV/div.). Bottom trace: load current (5 A/div.). Current slew rate: 0.1 A/s. Co = 1 F ceramic. Time scale: 0.2
ms/div.
Fig. 2.5V.6: Output voltage response to load current stepchange (5 A – 10 A – 5 A) at Vin = 48 V. Top trace: output voltage (100 mV/div.). Bottom trace: load current (5 A/div.). Current slew rate: 5 A/s. Co = 450 F tantalum + 1 F ceramic.
Time scale: 0.2 ms/div.
MCD10085 Rev. 1.1, 08-Jul-10
Page 9 of 30
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SemiQ
SQM48 Series Data Sheet
Family 25A DC-DC Converters
SQM48T/S25025 (2.5 Volts Out)
is
10 H
source
inductance
Vsource
ic
33 F
ESR
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