Astec ALO25F24 Single output 8th brick: open-frame module Datasheet

Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
ALO25F24 Single Output 8th Brick: Open-Frame Module
The ALO25F24 is Astec’s 8th Brick industry standard offering. Operating from an input voltage range of 18V to 36V. It
delivers up to 25A max current at 3.3V output voltage. It provides tight regulation and exhibits clean and monotonic output
start up characteristics. This model comes with industry standard features such as Input UVLO; Enable On/Off, OCP, OVP and
OTP; Output Trim; Differential Remote Sense pins. Open frame construction is available with TH and SMT termination. With
its wide operating temperature range of -40°C to 85°C ambient, the converter is deployable into almost any environment.
Electrical Parameters
Input
Input Range
Input Surge
18-36 VDC
50V / 100ms
Control
Enable
TTL compatible
(Positive or Negative Logic Enable Options)
Output
Special Features
•
•
•
•
•
•
•
•
Industry Standard 8th Brick Footprint
Open frame construction
Low Ripple and Noise
Regulation to zero load
High Capacitive Load Start-up
Fixed Switching Frequency
Industry standard features: Input UVLO;
Enable; OVP, OCP and OTP; Output Trim,
Remote Sense
Meets Basic Insulation
Load Current
Line/Load Regulation
Ripple and Noise
Output Voltage
Adjust Range
Transient Response
Remote Sense
Over Current
Protection
Over Voltage
Protection
Over Temperature
Protection
3.3V @ 25A max (PO = 82.5W)
< 1% VO
75mVP-P
±10% VO
5% Typical deviation
50% to 75% Load Change
100µ
µs settling time (Typ)
+10%VO
120% (Typ)
130% (Typ)
103°°C
Environmental Specifications
Safety
•
•
•
UL + cUL 60950, Recognized
EN60950 through TUV-PS
-40ºC to 85ºC Operating Temperature
-40ºC to 125ºC Storage Temperature
MTBF > 1 million hours
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
SHEET 1 OF 13
Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
Electrical Specifications
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 Voltage
Continuous
Transient (100ms)
Device
Symbol
Min
Typical
Max
Unit
All
Vin
Vin trans
-
-
36
50
Vdc
All
All
All
All
All
All
TA
TSTG
PO,MAX
-40
-40
10
-
-
1500
85
125
85
25
82.5
Vdc
ºC
ºC
%
Vdc
W
Symbol
VIN
Min
18
Typical
24
Max
36
Unit
Vdc
17.2
15.8
-
17.95
16.50
Vdc
5
1
-
-
6.0
ms
-
-
4.6
W
-
6
-
mAp-p
All
-
-
1.7
V/ms
All
-
-
5
Apk
I/O Isolation
(Conditions 50µA for 5 sec, slew
rate of 1500V/10sec)
Input-to-Output
Operating Temperature
Storage Temperature
Operating Humidity
Max Voltage at Enable Pin
Max Output Power
INPUT SPECIFICATIONS
Parameter
Operating Input Voltage Range
Input Under-Voltage Lock-out
T_ON Threshold
T_OFF Threshold
Input Line Drop Out Time (25°C)
- within overshoot spec
- within 450mV overshoot
Max Input Current 1
(VIN = VIN, Min ; IO = IO, Max)
Max Pdiss @ IO = 0A
(VIN = VIN, Nom)
Temperature: TA = 25°C
Input Ripple Current 2
5Hz to 20MHz
Input Voltage Rise Time
10% to 90% of Vout
Inrush Current
dIIN/dt
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
Device
All
All
All
All
All
VIN
VIN
Iinmax
All
All
II1
A
SHEET 2 OF 13
Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
Electrical Specifications (continued)
OUTPUT SPECIFICATIONS
Parameter
Output Voltage Set point
VIN = VIN, Min to VIN, Max
IO = IO, Max
Output Regulation
Line
VIN = VIN, Min to VIN, Max
Load
IO = IO, Min to IO, Max
Temperature:
TA = -40°C to 85°C
Output Ripple and Noise 3
Peak-to-Peak: (5Hz to 20MHz)
External Load Capacitance
Capacitor ESR
Output Current 4
Output Current-limit Inception
VOUT = 90% VO, Set ;
TA = 25°C
Output Over Voltage Protection
Over Temperature Protection
Device
All
Symbol
VO, SET
Min
3.24
Typical
3.30
Max
3.35
Unit
Vdc
All
-
-
-
± 0.20
%
-
-
-
± 0.20
-
-
-
± 1.00
All
-
-
40
75
mVp-p
All
-
All
All
IO
IO
15
0
26.5
-
15,000
25
35
µF
mΩ
A
A
All
All
VO
3.9
103
4.1
-
4.9
117
°C
All
η
87
88
-
%
All
-
-
-
15
ms
All
-
-
-
15
ms
All
-
-
-
15
ms
All
All
All
-
580
90
660
-
740
10
110
kHz
%VO
%VO
All
-
0.01
-
-
V/ms
-
0
2.95
-
0.8
20
V
V
-
2.95
0
-
20
0.8
V
V
V
(AVG. PCB TEMP)
Efficiency
VIN = VIN, Nom; IO = IO, Max
TA = 25ºC
Turn On Response Time
VIN = VIN, Min toVIN, Max
Enable to Output Turn-On Delay
VIN = VIN, Min toVIN, Max
IO = IO, Min to IO, Max
+ VIN to Output Turn-On Delay
Enable Pin: Active
VIN = VIN, Nom
IO = IO, Max
Switching Frequency
Output Voltage Remote Sensing
Output Voltage Trim Range 5
Output Enable ON/OFF 6
Enable Signal Slew Rate
Negative Enable (“N” suffix)
Enable Pin Voltage: Mod-ON
Mod-OFF
Positive Enable (No suffix)
Enable Pin Voltage: Mod-ON
Mod-OFF
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
SHEET 3 OF 13
Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
Electrical Specifications (continued)
OUTPUT SPECIFICATIONS
Parameter
Dynamic Response
CO = 0µF
Device
Symbol
∆IO/∆t
-
Peak Deviation
Load Change from IO = 50% to
75% of IO, Max :
Settling Time to VO, Set Tolerance
All
Peak Deviation
Load Change from IO = 50% to
25% of IO, Max :
Settling Time to VO, Set Tolerance
Output Overshoot
At T-on / t-off
Passive Resistive Full Load
T < 0°C
All
All
All
Min
Typical
Max
Unit
-
0.1
-
A/µs
-
-
5
-
-
100
-
300
µs
3
%VO
-
-
-
4
%VO
100
%VO
µs
300
5
%VO
Note: 1. The converter is not internally fused. An input line fuse such as Littlefuse 3AB type must be used.
2. Refer to Figure 1 for the external input capacitance required.
3. Refer to Figure 2 for output ripple and noise test measurement setup.
4. Output power derating applies at elevated temperature. Refer to Figure 11.
5. Refer to the output trim equations provided (Equations 1 and 2).
6. For temperature greater than -20°C, minimum pin disable time is 100ms.
For temperature less than -20°C, minimum pin disable time is 1s.
SAFETY AGENCY / MATERIAL RATING / ISOLATION
Parameter
Safety Approval
Device
All
Material Flammability Rating
Parameter
Input to Output Capacitance
Input to Output Resistance
Input to Output Insulation Type
All
Device
All
All
All
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
UL/cUL 60950, 3rd Edition – Recognized
EN 60950 through TUV
UL94V-0
Symbol
Min
Typical
Max
1000
TBD
Basic
-
Unit
pF
Ohms
-
SHEET 4 OF 13
Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
Electrical Specifications (continued)
TO OSCILLOSCOPE
Vi(+)
Ltest
12 uH
BATTERY
Cs 220 uF
ESR < 0.1 OHM
@ 20 ºC, 100 kHz
33 uF
ESR < 0.7 OHM
@ 20 ºC, 100 kHz
Vi(-)
Measure input reflected-ripple current with a simulated source inductance (Ltest) of
12uH. Capacitor Cs offsets possible battery impedance. Measure current as shown
above.
Figure 1. Input Reflected Ripple Current Measurement Setup.
COPPER STRIP
Vo(+)
0.1 uF
10 uF SCOPE
RESISTIVE
LOAD
Vo(-)
Use a 0.1µF @50V X7R ceramic capacitor (connected an inch away from the output
terminals of the UUT) and a 10µF @ 25V tantalum capacitor (2 inches away from
the output terminals of the UUT). Scope measurement should be made using a BNC
socket, positioned 3 inches away from output terminals of the converter.
Figure 2. Peak to Peak Output Noise Measurement Setup.
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
SHEET 5 OF 13
Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
Basic Operation and Features
INPUT UNDER VOLTAGE LOCKOUT
To prevent any instability to the converter, which may affect the end system, the converter have been designed to turn-on once
VIN is in the voltage range of 17.2-17.95 VDC. Likewise, it has also been programmed to turn-off when VIN drops down to
15.8-16.5 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
Vadj
Radj_up
+Sense
Equation (1a):
Radj_up =
+Vin
+Vout

 5.1 × Voset × ( 100 + ∆%) 510

−
− 10.2 ΚΩ
∆%
1.225 × ∆%


Figure 3. Trim UP test configuration (Pin Side Up).
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
-Sense
Radj_down
Enable
Equation (2):
Radj_down
-Vout
Rload
Vadj
+Sense
 510 − 10.2 ⋅ kΩ


 ∆%

Where: ∆% = percent change in output voltage
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
+Vin
+Vout
Figure 4. Trim DOWN test configuration (Pin Side Up).
SHEET 6 OF 13
Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
Basic Operation and Features (continued)
OUTPUT ENABLE
The converter comes with an Enable pin (PIN 2), which is primarily used to turn ON/OFF the converter. Both a Positive (no
“N” suffix required) and a Negative (suffix “N” required) Enable Logic options are being offered.
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.
OVER CURRENT PROTECTION (OCP)
The Over Current Protection is latching with auto-restart. The converter shuts down once the output current reaches the OCP
range. The converter will attempt to restart until the fault is removed. Latching OCP mode is available as an option (no model
part number assigned). This feature is only for module protection and no intention to customer application.
OUTPUT OVER VOLTAGE PROTECTION (OVP)
The Over Voltage Protection circuit is latching with auto-restart. The converter will latch-off and attempt to restart until the
fault is removed. Latching OVP mode is available as an option (no model part number assigned).
OVER TEMPERATURE PROTECTION (OTP)
The Over Temperature Protection circuit will shutdown the converter once the average PCB temperature reaches the OTP
range. This feature prevents the unit from overheating and consequently going into thermal runaway, which may further
damage the converter and the end system. Such overheating may be an effect of operation outside the given power thermal
derating conditions. Restart is possible once the temperature of the sensed location drops to less than 103°C.
REMOTE SENSE
The remote 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. The combination of remote sense and trim adjust cannot
exceed 110% of VO. When output voltage is trimmed up (through remote sensing and/or trim pin), output current must be
derated and maximum output power must not be exceeded.
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
SHEET 7 OF 13
Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
Performance Curves
Pow er Dissipation vs. Output Current, TA=25°C
Efficiency vs. Output Current, TA=25°C
90%
12
Power Dissipation [W]
95%
14
Efficiency [%]
85%
80%
75%
70%
65%
Vin = 18Vdc
Vin = 24Vdc
60%
10
8
6
4
Vin = 18Vdc
Vin = 24Vdc
2
Vin = 36Vdc
Vin = 36Vdc
55%
0
0
5
10
15
Output Current [A]
20
25
0
5
10
15
Output Current [A]
20
Figure 5. Efficiency vs. Load Current at IO = Full Load,
TA = 25°C (ambient temperature).
Figure 6. Power Dissipation vs. Load Current at
IO = Full Load, TA = 25°C (ambient temperature).
Figure 7. Output Turn On Response Time at VIN = 24V,
IO = Full Load TA = 25°C.
Figure 8. Output Ripple Waveform at VIN = 24Vdc,
IO = Full Load, TA = 25°C.
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
25
SHEET 8 OF 13
Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
Performance Curves
Figure 9. Output Transient Response at TA = 25°C;
Peak Deviation (Hi - Lo).
Figure 10. Output Transient Response at TA = 25°C;
Peak Deviation (Lo - Hi).
ALO25F24 Derating Curve @ 24Vin
25
Output Current
20
15
10
400 LFM
300 LFM
200 LFM
100 LFM
0 LFM
5
0
25
40
55
70
Am bient Tem p (°C)
85
Figure 11. Output Current vs. Temperature at VIN =24V,
IO = Full Load, TA = 25°C.
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
Figure 12. Enable to Output Turn On Time at VIN =24V,
IO = Full Load, TA = 25°C.
SHEET 9 OF 13
Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
Input Filter for FCC Class B Conducted Noise
A reference design for an input filter that can provide FCC Class B conducted noise levels is shown below (See Figure 13).
Two common mode connected inductors are used in the circuit along with balanced bypass capacitors to shunt common mode
currents into the ground plane. Shunting noise current back to the converter reduces the amount of energy reaching the input
LISN for measurement.
The application circuit shown has an earth ground (frame ground) connected to the converter output (-) terminal. Such a
configuration is common practice to accommodate safety agency requirements. Grounding an output terminal results in much
higher conducted emissions as measured at the input LISN because a hard path for common mode current back to the LISN is
created by the frame ground. “Floating” loads generally result in much lower measured emissions. The electrical equivalent of
a floating load, for EMI measurement purposes, can be created by grounding the converter output (load) through a suitably
sized inductor(s) while maintaining the necessary safety bonding.
FILTER
PARTS LIST
CKT CODE
Common
Mode Choke
X-Cap
Y-Cap
Cin
DESCRIPTION
CTX01-15091
Cooper Electronic
Technologies
0.47 µF X 4pcs
22 nF X 4 pcs
220µF X 1pc
Figure 13: Class B Filter Circuit
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
SHEET 10 OF 13
Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
Mechanical Specifications
Parameter
Dimension
Weight
PIN ASSIGNMENT
1
2
3
4
Device
All
Symbol
L
W
H
All
+VIN
ENABLE
-VIN
-Vo
Min
-
Typ
2.30 [58.42]
0.80 [20.32]
-
Max
0.32 [8.13]
Unit
in [ mm ]
in [ mm ]
in [ mm ]
-
24 [0.85]
-
g [oz]
5
6
7
8
-SENSE
TRIM
+SENSE
+Vo
Figure 14A. Mechanical Outline (Pin Version)
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
SHEET 11 OF 13
Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
Mechanical Specifications (continued)
Figure 14B. Mechanical Outline (Surface Mount)
Figure 15. Recommended Pad layout for SMT (Suffix “S”) version.
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
SHEET 12 OF 13
Technical Reference Notes
ALO25F24
(Single Output 8th Brick)
RECOMMENDED REFLOW PROFILE
SOLDERING CONSIDERATIONS
240
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.
PEAK TEMPERATURE
200°°C - 230°°C
220
200
TEMPERATURE (deg C)
The ALO25F24 converter is 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.
183°°C
180
REFLOW
ZONE
160
140
< 80 sec
110°°C
120
100
120 - 180 sec
PRE-HEAT ZONE
80
60
SLOPE
< 4°°C /sec
40
20
For SMT terminated modules, refer to Figure 16 for
the recommended reflow profile.
0
0
30
60
90
120
150
180
210
240
270
300
TIME (seconds)
Figure 16. Recommended reflow profile for SMT modules.
PART NUMBERING SCHEME
CONSTRUCTION
A
w
L = Open frame
O/P CURRENT
O/P VOLTAGE
Vin
Enable
xx
y
24
N
O
25 = 25A
F = 3.3V
N = Negative
No suffix “N” = Positive
default
-
PIN LENGTH
TERMINATION
6
S
6 = 3.7mm
No suffix “-6” =
5mm default
S = SMT Termination
No suffix “-S” = TH
termination
Note: 1) For Through Hole (TH) termination: - Std pin length is 5mm nominal (min: 0.189 [4.8]; max: 0.205 [5.2] / in [mm])
- “-6” option is 3.7mm nominal (min: 0.137 [3.5]; max: 0.152 [3.9] / in [mm])
- Pins 4 & 8 diameter: ∅ = 0.062 [1.57], others: ∅ = 0.04 [1.0] (6X)
Please call 1-888-41-ASTEC for further inquiries or
visit us at www.astecpower.com
MODEL: ALO25F24
AUGUST 23, 2005 - REVISION H
SHEET 13 OF 13
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