Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
ALQ25 Single Output Open-Frame DC-DC Converter Module
Industry Standard ¼ Brick: 36V-75V Input / 5V Output
The ALQ25 series is Astec's next generation single output, high-density standard quarter brick offering. It operates from a 36V
to 75V DC Bus and comes in different Isolated Logic Output voltages (ILO) well suited for DPA applications. It’s designed to
conservatively handle 25A of output current for 5V and at high levels of efficiency (5V @ 91%). It provides tight regulation
and exhibits clean and monotonic output start up characteristics. The ALQ25’s come with industry standard features such as
Input UVLO, OCP, OVP, OTP, Output Trim, differential output Sense pins.
Electrical Parameters
Input
Input Range
Input Surge
Efficiency
36-75 VDC
100V / 100ms
91% (Typ)
Control
Enable
TTL compatible
(Positive and Negative Enable Options)
Output
Load Current
Special Features
•
•
•
•
•
•
•
•
Industry Standard ¼ Brick Footprint
Positive and Negative Enable Options
Regulation to Zero Load
High Capacitive Load Start-up
Fixed Switching Frequency at 200kHz
Output Trim
Input Under-Voltage Lockout
Low profile / open-frame
Load Regulation
Ripple and Noise
Output Voltage
Adjust Range
Transient Response
Remote Sense
Over Current
Protection
5.0V @ 25A max
Line Regulation 0.2 % Vo
0.4 % V O
150mVPK-PK max for 5V
±10% VO
5% VO deviation (Typ)
50% to 75% Load Change
400µ
µ sec settling time (Typ)
+10% VO
140% IO,MAX
Environmental Specifications
•
•
•
-40ºC to 85ºC Operating Temperature
(200LFM)
-40ºC to 120ºC Storage Temperature
MTBF > 1 million hours
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
Safety
UL + cUL 60950, Recognized (Pending)
EN60950 through TUV-PS (Pending)
SHEET 1 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
ALQ25 Series
THIS SPECIFICATION COVERS THE REQUIREMENTS FOR A NEW ¼-BRICK SIZE
25A SINGLE OUTPUT HIGH EFFICIENCY DC/DC CONVERTER.
MODEL NAME
ALQ25A48
ALQ25A48N
ALQ25A48-7
ALQ25A48N-7
VOUT / IOUT
CONSTRUCTION
5.0V/25A
5.0V/25A
5.0V/25A
5.0V/25A
OPTIONS:
Negative Enable:
Positive Enable:
5.8mm pin option
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
Serial No. Prefix
B737
B742
C511
C514
SUFFIX
"N"
No suffix
-7
SHEET 2 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
Electrical Specifications
STANDARD TEST CONDITION on a single module unless otherwise specified.
TA
Airflow
-VIN
ENABLE
+VIN
-VOUT
-Sense
Trim
+Sense
+Vout
PIN 1
PIN 2
PIN 3
PIN 4
PIN 5
PIN 6
PIN 7
PIN 8
25°C (Ambient Air)
See derating curve
48V ± 2V
Dependent on model series
Return pin for +VIN
Connected to Load (return)
Connected to -VOUT
Open
Connected to +VOUT
Connected to Load
ABSOLUTE MAXIMUM RATINGS
Stresses in excess of the absolute maximum ratings can cause permanent damage to the converter. Functional
operation of the device is converter is not implied at these or any other conditions in excess of those given in the
operational section of the specs. Exposure to absolute maximum ratings for extended period can adversely affect
device reliability.
Parameter
Input Voltage1
Continuous
Transient (100ms)
Isolation Voltage
Input to Output
Operating Ambient Temperature
(200LFM)
Storage Temperature
Operating Humidity
Max Output Power
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
Device
Symbol
Min
Typ
Max
Unit
All
All
VIN
VI N, trans
0
0
-
80
100
Vdc
Vdc
All
All
TA
-40
-
1500
+85
Vdc
ºC
All
All
TSTG
-
-40
-
-
120
85
ºC
%
A (5.0V)
PO
-
-
125
W
SHEET 3 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
INPUT SPECIFICATION
Parameter
Operating Input Voltage
Device
All
Input Under-Voltage Lock-out
T_ON Threshold
T_OFF Threshold
Maximum Input Current1
Conditions: VIN =VIN,min
IO = IO,max; TA = 25 ºC
Max PDISS @ IO = 0A (VIN = VIN,NOM)
Input Reflected Ripple Current2
Conditions: PO = PO,max; TA = 25 ºC
BW: 5Hz to 20MHz
Note:
Symbol
VIN
Min
36
Typ
48
Max
75
Unit
VDC
34
33
-
36
35
6
Vdc
IIN,max
31
30
-
-
-
7.5
W
-
-
260
mA PK-PK
All
A (5.0V)
A (5.0V)
All
II1/ II2
A
1. An input line fuse is recommended for use.
2. External input capacitance required. See Input Ripple Current test measurement setup on Fig 1.
OUTPUT SPECIFICATIONS
Parameter
Output Voltage Set point
VIN = VIN, min to VIN, max;
IO =IO,Max
Output Regulation
Line: VIN = VIN, Min to VIN,
Load: IO = IO, Min to IO, Max
Max
Device
A (5.0V)
Symbol
VO,SET
Min
4.9
Typ
5.0
Max
5.1
Unit
Vdc
A (5.0V)
A (5.0V)
-
-
0.1
0.2
0.2
0.4
%Vo
%Vo
-
-
-
0.02
% / °C
150
mVp-p
Temperature: Ta = -40 ºC to
+85ºC
Ripple and Noise3
Peak-to-Peak: (5Hz to 20MHz)
A (5V)
-
Output Current4
A (5V)
IO
0
-
25
A
External Load Capacitance
A (5V)
-
470
-
8000
µF
Output Current-limit Inception
VOUT = 90% VO,SET
A (5V)
IO
27.5
-
35
A
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
SHEET 4 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
OUTPUT SPECIFICATIONS
Parameter
Over Voltage Protection Range
Over Temperature Range
Device
A (5.0V)
Symbol
All
Min
6
Typ
Max
7
Unit
110
-
120
°C
(AVG PCB TEMPERATURE)
Efficiency
VIN = VIN-NOM; IO = IO,MAX
TA =25°C
Turn-On Response Time
VIN = VIN-MIN to VIN-MAX
Switching Frequency
A (5.0V)
η
89
91
-
%
All
All
-
-
200
20
ms
KHz
-
-
0.1
-
A/µs
-
-
500
mV
-
-
Dynamic Response5 :
∆IO /∆t=0.1A / uS
Load Change from IO = 10% to 100% of
IO, Max:
Peak Deviation Settling Time to VO, Nom
5V
Load Change from IO = 50% to 25% of
IO, Max:
Peak Deviation Settling Time to VO, Nom
Output Overshoot
at T-on / T-off
Passive Resistive Full Load
5V
Note:
V
All
µs
250
400
-
250
mV
5
µs
%Vo
3. See Figure 2 for Ripple and Noise test measurement setup.
4. Appropriate Thermal Derating applies. See Figure 13 for the Thermal Derating Curves
5. The Dynamic Deviation and Recovery time are defined as below
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
SHEET 5 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
FEATURE SPECIFICATION
Parameter
Output Enable ON/OFF10
Negative Enable ("N" suffix)
Enable Pin voltage for Module ON
Module OFF
Positive Enable (No suffix)
Enable Pin voltage for Module ON
Module OFF
Output Voltage Remote Sensing11,13
Output Voltage Trim Range
Note:
12,13
Device
Symbol
Min
Typ
Max
Unit
N
suffix
-
-0.7
3.5
-
1.2
12
V
V
No
suffix
All
-
3.5
-0.7
-
-
12
1.2
10
V
% VO
110
% VO
All
90
10. See Basic Operation and feature section for the recommended/ appropriate Module Enable configuration.
11. The sense pins can be used to compensate for any voltage drops (per indicated max limits) that may
occur along the connection between the output pins to the load. Pin 7 (+Sense) and Pin 5
(-Sense) should be connected to Pin 8 (+Vout) and Pin 4 (Return) respectively at the point where
regulation is desired.
12. Refer to Equation (1) and (2) and Figures 3 and 4 for the Output Trim Adjust configuration.
13. The combination of remote sense and Trim adjust cannot exceed 110% of VO, NOM.
ISOLATION SPECIFICATION
Parameter
Device
Symbol
Min
Typ
Max
Unit
Isolation Capacitance
All
-
-
1000
-
pF
Isolation Resistance
All
-
10
1000
-
MΩ
SAFETY APPROVAL
The ALQ25 series have been certified through:
• UL + cUL 60950, Third Edition - Recognized
• EN 60950 through TUV-PS
• Basic Insulation
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
SHEET 6 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
TO OSCILLOSCOPE
Vi(+)
Ltest
12 uH
Cs 220 uF
ESR < 0.1 OHM
@ 20 ºC, 100 kHz
BATTERY
33 uF
ESR < 0.7 OHM
@ 20 ºC, 100 kHz
Vi(-)
Note:
Measure the input reflected ripple current with a simulated source
inductance (Ltest) of 12uH. Capacitor Cs offsets possible battery/
source impedance. Measure current as shown above.
Figure 1. Input Reflected Ripple Current Measurement Setup.
COPPER STRIP
Vo(+)
1 uF
10 uF
SCOPE
RESISTIVE
LOAD
Vo(-)
Note:
Use a 1µF 50V X7R ceramic capacitor and a 10µF 25V tantalum cap.
Scope measurement should be made using a BNC probe socket positioned
about 76mm (3 in.) away from the module’s output terminals. The ext.
capacitors should be placed between the BNC socket and the module’s
output terminals, with a minimum distance of 51mm (2in.) from the latter.
Figure 2. Peak to Peak Output Noise Measurement Setup.
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
SHEET 7 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
F1
+VIN
+VOUT
+SENSE
Vin
CNT1
Cin
TRM
Co1
Co2
LOAD
S1
-SENSE
-VIN
-VOUT
Figure 3. Setup for Parametric Test.
F1: Fuse*: Use external fuse (fast blow type 10A) for each unit.
Cin: Recommended input capacitor 100uF/100V high frequency low ESR electrolytic type capacitor .(NICHICON
KME serial OR equate.)
Co1: Recommended 1uF /25V ceramic capacitor
Co2: Recommended output capacitor 1000uF/ 10V high frequency low ESR electrolytic type capacitor. (NICHICON
LXV serial OR equate.)
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
SHEET 8 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
Basic Operation and Features
INPUT UNDER VOLTAGE LOCKOUT
To prevent any instability to the converter, which may affect the end system, the ALQ25 series have been designed to turn-on
once VIN is in the voltage range of 34 - 36 VDC. Likewise, it has also been programmed to turn-off when VIN drops down to 33
- 35 VDC.
OUTPUT VOLTAGE ADJUST/TRIM
The converter comes with a TRIM pin (PIN 6), which is used to adjust the output by as much as 90% to 110% of its set point.
This is achieved by connecting an external resistor as described below.
To INCREASE the output, external Radj_up resistor
should be connected between TRIM PIN (Pin6) and
+SENSE PIN (Pin 7). Please refer to Equation (1) for the
required external resistance and output adjust
relationship.
-Vin
-Vout
-Sense
ENABLE
Rload
Trim
Radj_up
+Sense
Equation (1):
R adj− up =
5 .1 × V o × (100 + ∆ %) 510
−
− 10 .2 ( KΩ)
1. 225 × ∆ %
∆%
To DECREASE the output, external Radj_down resistor
should be connected between TRIM PIN (Pin 6) and
-SENSE PIN (Pin 5). Please refer to Equation (2) for the
required external resistance and output adjust
relationship.
+Vin
Figure 3. External resistor configuration to increase the outputs
-Vin
510
− 10 .2 ( KΩ )
∆%
-Vout
-Sense
Radj_down
ENABLE
R adj− down =
+Vout
Trim
Rload
+Sense
+Vin
+Vout
Figure 4. External resistor configuration to decrease the outputs
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
SHEET 9 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
OUTPUT ENABLE
The ALQ25 series comes with an ENABLE pin (PIN 2), which is primarily used to turn ON/OFF the converter. Both a
Positive (no part number suffix required) and a Negative (suffix “N” required) Enable Logic options are being offered. Please
refer to Table 2 for the Part Numbering Scheme.
For Positive Enable, the converter is turned on when the ENABLE pin is at logic HIGH or left open. The unit turns off when
the ENABLE pin is at logic LOW or directly connected to -VIN. On the other hand, the Negative Enable version turns unit on
when the ENABLE pin is at logic LOW or directly connected to -VIN. The unit turns off when the ENABLE pin is at Logic
HIGH.
OUTPUT OVER VOLTAGE PROTECTION (OVP)
The Over-Voltage Protection consists of circuitry that monitors the voltage on the output terminals. If the output voltage
exceeds the Over Voltage Protection threshold limit, module will work on intermittent model. When the Over Voltage
condition is removed, the module will automatically restart.
The protection mechanism is such that the unit can continue in this condition until the fault is cleared.
OVER CURRENT PROTECTION (OCP)
The Over Current Protection circuit comes in latching mode. The converter is latched off if the load current on the output
reaches the OCP threshold limit. The OCP latch can be reset either by cycling the input voltage or toggling the Enable signal
for 100ms. Consult factory for Auto-restart option.
The Over Current Protection (OCP) circuit comes in foldback current limit. If output current exceed the OCP threshold limit,
or at a short circuit condition, the module will work on intermittent model. When the Over Current condition is removed, the
module will automatically restart.
OVER TEMPERATURE PROTECTION (OTP)
These modules feature an over-temperature protection circuit to safeguard against thermal damage. The module will work on
intermittent mode when the maximum device reference temperature is exceeded. When the over-temperature condition is
removed, the converter will automatically restart
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
SHEET 10 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
Performance Curves
ALQ25A48 (5.0V) SERIES
Efficiency vs. Load Curve
Efficiency vs. Load Curve
100
100
90
90
80
80
70
60
Min
50
Max
40
Ave
30
Efficiency (%)
Efficiency [%]
70
Min
60
Max
50
Ave
40
30
20
20
10
10
0
10%
20%
30%
40%
50%
60%
70%
80%
90%
0
10%
100%
Load [A]
20%
30%
40%
50%
60%
70%
80%
90%
100%
Load (A)
Figure 5. Efficiency vs. Load Current Curves at TA =25°C
for 36Vin
Figure 6. Efficciency vs Load Current Curves at TA =25°C
For 48Vin
Efficiency vs. Load Curve
100
90
80
Efficiency (%)
70
Min
60
Max
50
Ave
40
30
20
10
0
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Load (A)
Figure 7. Figure 6. Efficciency vs Load Current Curves at
TA =25°C for 75Vin
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
SHEET 11 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
CURRENT VS. TEMPERATURE CURVES
Derating curve of ALQ25A48.
ALQ25A48 36v DERATING CURVE
OUTPUT CURRENT (A)
25.0
20.0
000 LFM
15.0
100 LFM
200 LFM
10.0
300LFM
400 LFM
5.0
0.0
25
40
55
70
85
Temperature (C)
ALQ25A48 48v DERATING CURVE
OUTPUT CURRENT (A)
25.0
20.0
000 LFM
100 LFM
200 LFM
300 LFM
400 LFM
15.0
10.0
5.0
0.0
25
40
55
70
85
Temperature (C)
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
SHEET 12 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
ALQ25A48 75v DERATING CURVE
OUTPUT CURRENT (A)
25.0
20.0
000 LFM
100 LFM
15.0
200 LFM
10.0
300 LFM
400 LFM
5.0
0.0
25
40
55
70
85
Temperature (C)
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
SHEET 13 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
Mechanical Specifications
Figure 15. ALQ25 Series Mechanical Outline Drawing
Parameter
Dimension
Device
All
Symbol
L
W
H
Weight
PIN ASSIGNMENT
J1
J2
J3
J4
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
Min
-
Typ
2.28 [57.9]
1.45 [36.8]
0.43 [9.70]
Max
-
Unit
in [ mm ]
in [ mm ]
in [ mm ]
-VIN
ENABLE
+VIN
-VO
g [oz]
J5
J6
J7
J8
-SENSE
TRIM
+SENSE
+VO
SHEET 14 OF 15
Technical Reference Notes
ALQ25 Series
(Open Frame Single Output Quarter Brick)
Mechanical Specifications
(continued)
SOLDERING CONSIDERATIONS
The ALQ25 series converters are compatible with standard wave soldering techniques. When wave soldering, the
converter pins should be preheated for 20-30 seconds at 110°C and wave soldered at 260°C for less than 10 seconds.
When hand soldering, the iron temperature should be maintained at 425°C and applied to the converter pins for less
than 5 seconds. Longer exposure can cause internal damage to the converter. Cleaning can be performed with cleaning
solvent IPA or with water.
PART NUMBERING SCHEME FOR ORDERING
OUTPUT
CURRENT
OUTPUT
VOLTAGE
INPUT
VOLTAGE
ENABLE LOGIC
ALQ25
x
48
y
A = 5.0V
N
= Negative
Enable
“Blank” = Positive Enable
(Default)
Please call 1-888-41-ASTEC for further inquiries
or visit us at www.astecpower.com
MODEL: ALQ25 SERIES
Dec 1, 2003 - REVISION B
SHEET 15 OF 15