Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
ALD12/18/20/25 Single Output 16th Brick: 60Watts
The ALD12/18/20/25 series is Astec’s latest 16th Brick industry standard offering. Operating from an input voltage range of 36V to
75V, the series provides 6 configured outputs from 1.2V all the way up to 5V. It delivers up to 25A max current for 1.8V and
lower at impressive levels of efficiency. The series comes with industry standard features such as Input UVLO; non-latching OCP,
OVP and OTP; Output Trim; Differential Remote Sense pins. With its wide operating temperature range of -40°C to 85°C
ambient, the converters are deployable into almost any environment.
Electrical Parameters
Input
Input Range
Input Surge
36-75 VDC
100V / 100ms
Control
Enable
TTL compatible
(Positive or Negative Logic Enable Options)
Output
Special Features
•
•
•
•
•
•
•
•
Industry Standard 16th Brick Footprint
Low Ripple and Noise
Output pre-bias startup
Regulation to zero load
High Capacitive Load Start-up
Fixed Switching Frequency
Industry standard features: Input UVLO;
Enable; non-latching OVP, OCP and OTP;
Output Trim, Differential Remote Sense
Meets Basic Insulation
Load Current
Line/Load Regulation
Ripple and Noise
Adjust Range
Transient Response
Remote Sense
Over Current
Protection
Over Voltage
Protection
Over Temperature
Protection
Up to 25A max (VO ≤ 1.8V)
< 1% VO
40mVP-P typical
±10% VO
3% Typical deviation
50% to 75% Load Change
80µ
µs settling time (Typ)
+10%VO
120% max
130% max
110 °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: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
SHEET 1 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th 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 Voltage1
Continuous
Transient (100ms)
Isolation Voltage
Input to Output
Operating Temperature
Storage Temperature
Operating Humidity
Max Voltage at Enable Pin
Max Output Power
Device
Symbol
Min
Typ
Max
Unit
All
VIN
VIN, trans
-0.3
-
-
75
100
Vdc
1500
-40
-40
10
-0.6
-
-
85
125
85
25
60
60
50
45
38
30
Vdc
ºC
ºC
%
Vdc
W
W
W
W
W
W
Min
36
Typ
48
Max
75
Unit
Vdc
34.0
31.0
-
34.8
32.5
-
Vdc
-
-
-
-
36.0
33.5
2.4
2.4
1.9
1.6
1.4
1.1
4.1
3.9
3.4
3.4
3.4
2.6
10
mAp-p
-
1
-
V/ms
-
-
1
A2/s
All
All
All
All
All
A (5V0)
F (3V3)
G (2V5)
Y (1V8)
M (1V5)
K (1V2)
Ta
TSTG
-
INPUT SPECIFICATIONS
Parameter
Operating Input Voltage Range
Input Under-Voltage Lock-out
T_ON Threshold
T_OFF Threshold
Input Current1
(VIN = VIN, Min; IO = IO, Max)
Max Pdiss @ IO = 0A
(VIN = VIN, Nom; TA ≥ 25°C)
Input Ripple Current2
5Hz to 20MHz
Input Voltage Rise Time
10% to 90% of Vout
Inrush Current
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
Device
All
All
5V0 (A)
3V3 (F)
2V5 (G)
1V8 (Y)
1V5 (M)
1V2 (K)
5V0 (A)
3V3 (F)
2V5 (G)
1V8 (Y)
1V5 (M)
1V2 (K)
All
Symbol
VIN
IIN-MAX
II1
All
All
I2/s
A
W
SHEET 2 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Electrical Specifications (continued)
OUTPUT SPECIFICATIONS
Parameter
Output Voltage Set point
VIN = VIN, MIN to VIN,MAX;
IO =IO,Max
Device
5V0 (A)
3V3 (F)
2V5 (G)
1V8 (Y)
1V5 (M)
1V2 (K)
Symbol
VO,SET
Min
4.930
3.260
2.465
1.770
1.470
1.180
Typ
5.000
3.300
2.500
1.800
1.500
1.200
Max
5.070
3.340
2.535
1.830
1.530
1.220
Unit
Vdc
Vdc
Vdc
Vdc
Vdc
Vdc
All
-
-
0.1
0.4
%Vo
Load: IO = IO, Min to IO, Max
All
-
-
0.1
0.4
%Vo
Temperature: TA = -40 ºC to
+85ºC
Ripple and Noise3
Peak-to-Peak: (5Hz to 20MHz)
Output Current
All
-
-
0.3
0.8
%Vo
All
-
-
40
100
mVp-p
5V0 (A)
3V3 (F)
2V5 (G)
1V8 (Y)
1V5 (M)
1V2 (K)
All
IO
IO
6.2
4.1
3.2
2.4
2.1
1.6
-
12
18
20
25
25
25
10,000
19
25
30
34
34
34
6.9
4.9
3.9
2.9
2.5
2.1
120
A
5V0 (A)
3V3 (F)
2V5 (G)
1V8 (Y)
1V5 (M)
1V2 (K)
5V0 (A)
3V3 (F)
2V5 (G)
1V8 (Y)
1V5 (M)
1V2 (K)
All
0
0
0
0
0
0
4
13.0
19.5
21.5
26.5
26.5
26.5
5.9
3.9
3.0
2.1
1.8
1.4
110
5V0 (A)
3V3 (F)
2V5 (G)
1V8 (Y)
1V5 (M)
1V2 (K)
η
η
η
η
η
η
90.0
89.0
88.5
87.0
83.5
82.0
91.0
90.0
89.5
88.0
84.5
83.0
94.0
93.0
92.0
90.0
88.0
86.0
Output Regulation
Line: VIN = VIN, Min to VIN,
Max
External Load Capacitance
Capacitor ESR
Output Current-limit Inception
VOUT = 90% VO,SET
(Autorecovery)
Over Voltage Range
(Autorecovery)
Over Temperature Range
-
(AVG. PCB TEMP) - Auto recovery
Efficiency
VIN = VIN-NOM
IO = IO,MAX
TA=25°C
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
µF
mΩ
A
V
°C
%
%
%
%
%
%
SHEET 3 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Electrical Specifications (continued)
OUTPUT SPECIFICATIONS (continued)
Parameter
Turn-On Response Time4
VIN = VIN-MIN to VIN-MAX
Enable to Output Turn-ON Delay
VIN = VIN-MIN to VIN-MAX
IO = IO,MIN to IO,MAX
+VIN to Output Turn-On Delay
Enable Pin: Active
VIN = VIN-MIN to VIN-MAX
IO = IO,MIN to IO,MAX
Switching Frequency
Dynamic Response:
CO = use Figure 2 test setup
Peak Deviation for Load Step
Change from
IO = 50% to 75% of IO, Max :
Settling Time to within 1% of
output set point voltage – VO,SET:
Peak Deviation for Load Step
Change from
IO = 50% to 25% of IO, Max :
Settling Time to within 1% of
output set point voltage – VO,SET:
Output Overshoot at Turn-on
Passive Resistive Full Load
Output Enable ON/OFF
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
Output Voltage Remote Sensing
Output Voltage Trim Range5
Device
Symbol
All
All
-
All
All
2V5, 5V0
∆IO/∆t
Min
Typ
Max
Unit
-
2
-
5
10
ms
ms
-
-
-
10
ms
-
625
725
0.1
690
800
-
KHz
-
560
650
-
A/µs
All
-
-
3
6
% Vo
All
-
-
80
200
µs
All
-
-
3
6
% Vo
All
Vo ≤ 1V8
Vo > 1V8
-
-
80
0
0
200
5
4
µs
%Vo
All
N suffix
-
0.01
-
-
V/ms
-
-0.5
2.95
-
1.2
20
V
V
-
2.95
-0.5
90
-
20
1.2
10
110
V
No suffix
All
All
%VO
%VO
NOTES: 1. The converter is not internally fused; an external fuse must be used.
2. Refer to Figure 1 for the input reflected ripple test setup.
3. Refer to Figure 2 for the Output Ripple and Noise Test Measurement Setup.
4. Measure output rise time from 10%VO to 90%VO.
5. Refer to the output trim equations provided (Equations 1 and 2).
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
SHEET 4 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Electrical Specifications (continued)
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
UL/cUL 60950
TUV EN 60950
UL94V-0
Symbol
Min
-
Typical
1000
10
Basic
Max
-
Unit
pF
Mohms
-
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 12 uH.
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: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
SHEET 5 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th 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 34-36 VDC. Likewise, it has also been programmed to turn-off when VIN drops down to 31-33.5 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): 1.5V to 5V
Radj_up =
+Vin
+Vout
5.1 × Voset × ( 100 + ∆%) 510
−
− 10.2 ΚΩ
∆%
1.225 × ∆%
Figure 3. External resistor configuration to increase the outputs
Equation (1b): 1.2V
Radj_up =
5.1 × Voset × ( 100 + ∆%) 510
−
− 10.2 ΚΩ
∆%
0.6 × ∆%
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
-Vout
-Sense
Radj_down
Equation (2):
Radj_down
Enable
510 − 10.2 ⋅ kΩ
∆%
Vadj
Rload
+Sense
+Vin
+Vout
Where: ∆% = percent change in output voltage
Figure 4. External resistor configuration to increase the outputs
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.
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
SHEET 6 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Basic Operation and Features (continued)
OUTPUT ENABLE (continued)
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 circuit is non-latching - auto recovery mode. The converter will shut down and attempt to restart until
the fault is removed. There is a 20-50ms lockout period between restart attempts.
OVER CURRENT PROTECTION (OCP)
The Over Current Protection is non-latching - auto recovery mode. The converter shuts down once the output current reaches the
OCP range. The converter will attempt to restart until the fault is removed. There is a 20-50ms lockout period between restart
attempts. Note that the OCP threshold will be reduced proportionally with the output voltage trim up and/or remote sense
compensation. The percent rise in output voltage will be proportional to the reduction in OCP current inception.
OVER TEMPERATURE PROTECTION (OTP)
The Over Temperature Protection circuit will shutdown the converter once the average PCB temperature (See Figure 43A for OTP
reference sense point) 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 110°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
(-Vout) 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.
TO SOURCE
+Vin
+Vo
33uF
0.1uF
-Vin
10uF
-Vo
L
O
A
D
Figure 5. Typical Application Circuit
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
SHEET 7 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Performance Curves
5V Version
Power Dissipation vs. Output Current, TA=25°C
Efficiency vs. Output Current, TA=25°C
95%
10
Power Dissipation (Watts)
90%
Efficiency
85%
80%
75%
70%
Vin = 36Vdc
65%
Vin = 48Vdc
Vin = 75Vdc
60%
Vin = 36 Vdc
8
Vin = 48 Vdc
Vin = 75 Vdc
6
4
2
0
55%
0
2
4
6
8
Output Current (Amps)
10
12
0
2
4
6
8
Output Current (Amps)
10
Figure 6. 5V Efficiency vs. output current at various
input line conditions, TA = 25°C.
Figure 7. 5V Power Dissipation vs. load current at
various input line conditions, TA = 25°C.
Figure 8. 5V Startup Characteristic at VIN = 48Vdc, IO =
Full Load, TA = 25°C.
Figure 9. 5V Output Ripple at VIN = 48Vdc, IO = Full
Load, TA = 25°C.
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
12
SHEET 8 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Performance Curves
5V Version (continued)
ALD12A48 Current vs. Temperature
12
Output Current (A)
10
8
6
0 LFM
100LFM
200 LFM
300LFM
400 LFM
4
2
0
25
40
55
Temperature (°C)
70
85
Figure 10. 5V Output current vs. ambient temperature
curves at VIN = 48Vdc.
Figure 11. 5V Transient Response 50% to 75% step at
VIN = 48Vdc, TA = 25°C, di/dt = 0.1A/µs, CO = 0.
3.3V Version
Power Dissipation vs. Output Current, TA=25°C
Efficiency vs. Output Current, TA=25°C
10
95%
Power Dissipation (Watts)
90%
Efficiency
85%
80%
75%
70%
Vin = 36Vdc
65%
Vin = 48Vdc
60%
Vin = 36Vdc
8
Vin = 48Vdc
Vin = 75Vdc
6
4
2
Vin = 75Vdc
0
55%
0
3
6
9
12
Output Current (Amps)
15
18
Figure 12. 3.3V Efficiency vs. output current at various
input line conditions, TA = 25°C.
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
0
3
6
9
12
Output Current (Amps)
15
18
Figure 13. 3.3V Power Dissipation vs. load current at
various input line conditions, TA = 25°C.
SHEET 9 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Performance Curves
3.3V Version (continued)
Figure 14. 3.3V Startup Characteristic at VIN = 48Vdc,
IO = Full Load, TA = 25°C, CO = 0.
Figure 15. 3.3V Output Ripple at VIN = 48Vdc, IO =
Full Load, TA = 25°C.
ALD18F48 Current vs. Temperature
18
Output Current (A)
16
14
12
10
8
0LFM
6
100LFM
200LFM
300LFM
4
2
400LFM
0
25
40
55
Temperature (°C)
70
Figure 16. 3.3V Output current vs. ambient temperature
curves at VIN = 48Vdc.
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
85
Figure 17. 3.3V Transient Response 50% to 75% step at
VIN = 48Vdc, TA = 25°C, di/dt = 0.1A/µs, CO = 0.
SHEET 10 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Performance Curves
2.5V Version
Efficiency vs. Output Current, TA=25°C
Power Dissipation vs. Output Current, TA=25°C
10
95%
Power Dissipation (Watts)
90%
Efficiency
85%
80%
75%
70%
Vin = 36Vdc
65%
Vin = 48Vdc
60%
Vin = 75Vdc
55%
Vin = 36 Vdc
8
Vin = 48 Vdc
Vin = 75 Vdc
6
4
2
0
0
4
8
12
16
Output Current (Amps)
20
0
5
10
15
20
Output Current (Amps)
Figure 18. 2.5V Efficiency vs. output current at various
input line conditions, TA = 25°C.
Figure 19. 2.5V Power Dissipation vs. load current at
various input line conditions, TA = 25°C.
Figure 20. 2.5V Startup Characteristic at VIN = 36Vdc,
IO = Full Load, TA = 25°C, CO = 0.
Figure 21. 2.5V Output Ripple at VIN = 48Vdc, IO =
Full Load, TA = 25°C.
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
SHEET 11 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Performance Curves
2.5V Version (continued)
ALD20G48 Current vs. Tem perature
Output Current (A)
20
15
10
0 LFM
100 LFM
200 LFM
300 LFM
400 LFM
5
0
25
40
55
70
85
Ambient Tem perature (°C)
Figure 22. 2.5V Output current vs. ambient temperature
curves at VIN = 48Vdc.
Figure 23. 2.5V Transient Response 50% to 75% step at
VIN = 48Vdc, TA = 25°C, di/dt = 0.1A/µs, CO = 0.
1.8V Version
Efficiency vs. Output Current, TA=25°C
Power Dissipation vs. Output Current, TA=25°C
10
95%
Power Dissipation (Watts)
90%
Efficiency
85%
80%
75%
70%
Vin = 36Vdc
65%
Vin = 48Vdc
60%
Vin = 36 Vdc
8
Vin = 48 Vdc
Vin = 75 Vdc
6
4
2
Vin = 75Vdc
55%
0
0
5
10
15
20
Output Current (Amps)
Figure 24. 1.8V Efficiency vs. output current at various
input line conditions, TA = 25°C.
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
25
0
5
10
15
20
Output Current (Amps)
25
Figure 25. 1.8V Power Dissipation vs. load current at
various input line conditions, TA = 25°C.
SHEET 12 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Performance Curves
1.8V Version
Figure 26. 1.8V Startup Characteristic at VIN = 36Vdc,
IO = Full Load, TA = 25°C, CO = 0.
Figure 27. 1.8V Output Ripple at VIN = 48Vdc, IO =
Full Load, TA = 25°C.
ALD25Y48 Current vs. Temperature
Output Current (Amps)
25
20
15
10
0 LFM
100 LFM
200 LFM
5
300 FLM
400 FLM
0
25
40
55
Temperature (°C)
70
Figure 28. 1.8V Output current vs. ambient temperature
curves at VIN = 48Vdc.
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
85
Figure 29. 1.8V Transient Response 50% to 75% step at
VIN = 48Vdc, TA = 25°C, di/dt = 0.1A/µs, CO = 0.
SHEET 13 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Performance Curves
1.5V Version
Efficiency vs. Output Current, TA=25°C
Pow er Dissipation vs. Output Current, T A=25°C
95%
10
90%
Power Dissipation [W
Vin = 36Vdc
Efficiecny [%]
85%
80%
75%
70%
65%
Vin = 36Vdc
Vin = 75Vdc
6
4
2
Vin = 48Vdc
60%
Vin = 48Vdc
8
Vin = 75Vdc
55%
0
0
5
10
15
Output Current [A]
20
25
0
5
10
15
Output Current [A]
20
Figure 30. 1.5V Efficiency vs. output current at various
input line conditions, TA = 25°C.
Figure 31. 1.5V Power dissipation vs. output current at
various input line conditions, TA = 25°C.
Figure 32. 1.5V Startup Characteristic at VIN = 48V, TA
= 25°C.
Figure 33. 1.5V Output Ripple at VIN = 48Vdc, IO =
Full Load, TA = 25°C.
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
25
SHEET 14 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Performance Curves
1.5V Version (continued)
Output Current vs. Temperature
25
Current [A]
20
15
10
0 LFM (0 m/s)
100 LFM (0.5 m/s)
200 LFM (1m/s)
5
400 LFM (3 m/s)
0
25
40
55
70
Ambient Temperature [°C]
85
Figure 34. 1.5V Output current vs. ambient temperature
curves at VIN = 48Vdc.
Figure 35. 1.5V Output Transient Response 50% to 75%
step at VIN = 48Vdc, TA = 25°C, di/dt = 0.1A/µs, CO = 0.
1.2V Version
Power Dissipation vs. Output Curtret, TA=25°C
Efficiency vs. Output Current, TA=25°C
10
95%
Vin = 36Vdc
Power Dissipation [W
90%
Efficiecny [%]
85%
80%
75%
70%
65%
Vin = 36Vdc
Vin = 75Vdc
6
4
2
Vin = 48Vdc
60%
Vin = 48Vdc
8
Vin = 75Vdc
0
55%
0
5
10
15
Output Current [A]
20
Figure 36. 1.2V Efficiency vs. output current at various
input line voltage, TA = 25°C.
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
25
0
5
10
15
Output Current [A]
20
25
Figure 37. 1.2V Power dissipation vs. output current at
various input line conditions, TA = 25°C.
SHEET 15 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Performance Curves
1.2V Version (continued)
Figure 38. 1.2V Startup Characteristic at VIN = 48V, TA =
25°C.
Figure 39. 1.2V Output Ripple at VIN = 48Vdc, IO = Full
Load, TA = 25°C.
ALD25K48 Current vs. Tem perature
25
Output Current (A)
20
15
10
0 LFM
100 LFM
200 LFM
300 LFM
400 LFM
5
0
25
40
55
70
Am bient Tem perature (°C)
Figure 40. 1.2V Output current vs. ambient temperature
VIN = 48V, TA = 25°C.
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
85
Figure 41. 1.2V Output Transient Response 50% to 75%
step at VIN = 48Vdc, TA = 25°C, di/dt = 0.1A/µs, CO = 0.
SHEET 16 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th 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 42). 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.
PARTS LIST
CKT CODE
FILTER
Common
Mode Choke
X-Cap
Y-Cap
Cin
DESCRIPTION
CTX01-15091
Cooper Electronic
Technologies
0.47 µF X 4pcs
22 nF X 4 pcs
33 uF
Figure 42: Class B Filter Circuit
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
SHEET 17 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Mechanical Specifications
Parameter
Dimension
Device
All
Weight
Symbol
L
W
H
Min
1.28 [32.5]
0.88 [22.35]
0.33 [8.38]
Typ
1.30 [33.0]
0.90 [22.9]
0.35 [8.8]
Max
1.32 [33.5]
0.92 [23.36]
0.37 [9.39]
Unit
in [ mm ]
in [ mm ]
in [ mm ]
-
14.17 [0.54]
-
g [oz]
All
PIN ASSIGNMENT
1
2
3
4
+VIN
ENABLE
-VIN
-VOUT
5
6
7
8
-SENSE
TRIM
+SENSE
+VOUT
1.30 [33.0]
0.137 [3.5] MIN ({ -6 OPTION} PIN LENGHT).
0.152 [3.9] MAX
Pin 1
OTP Sense point
Pin 8
0.90 [22.9]
0.189[4.8]MIN.
(STD PIN LENGHT).
0.205 [5.2]MAX.
0.35 [8.8]
PIN SIDE DOWN
0.19 [4.8]
0.062 Ø [1.57Ø] (2x)
0.04Ø [1.0Ø](6X)
0.10 [2.5]
0.10 [2.5]
SIDE VIEW
1.10 [27.9]
0.15 [3.8]
0.15 [3.8]
0.30 [7.6]
0.15 [3.8]
0.45 [11.4]
0.60 [15.2]
0.30 [7.6]
0.60 [15.2]
PIN SIDE UP
Figure 43A. Mechanical Outline – Through hole termination
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
SHEET 18 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Mechanical Specifications (continued)
1.30 [33.0]
Pin 1
Pin 8
0.90 [22.9]
PIN SIDE DOWN
0.36 [9.0]
0.06 [1.4]
0.18 [4.6]
SIDE VIEW
0.15 [3.8]
1.10 [27.9]
0.15 [3.8]
0.15 [3.8]
0.30 [7.6]
0.10 [2.5]
0.45 [11.4]
0.60 [15.2]
0.30 [7.6]
0.30 [7.6]
PIN SIDE UP
Figure 43B. Mechanical Outline – SMT (Solder Ball) Termination.
SOLDERING CONSIDERATIONS
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.
For SMT terminated modules, refer to Figure 44 for
the recommended reflow profile.
RECOMMENDED REFLOW PROFILE
240
PEAK TEMPERATURE
200°°C - 230°°C
220
200
TEMPERATURE (deg C)
The through hole terminated converters are
compatible with standard wave soldering techniques.
When wave soldering, the converter pins should be
preheated for 20-30 sec at 110°C and wave soldered
at 260°C for less than 10 sec.
183°°C
180
REFLOW
ZONE
160
140
< 80 sec
110°°C
120
PRE-HEAT ZONE
120 - 180 sec
100
80
SLOPE
< 4°°C /sec
60
40
20
0
0
30
60
90
120
150
180
210
240
270
300
TIME (seconds)
Figure 44. Recommended reflow profile for SMT modules.
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
SHEET 19 OF 20
Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
PART NUMBERING SCHEME
CONSTRUCTION
A
W
O/P CURRENT
D
L = Open frame
E = Baseplate
Note:
O/P VOLTAGE
Vin
y
48
xx
12 = 12A
18 = 18A
20 = 20A
25 = 25A
25 = 25A
25 = 25A
A
F
G
Y
M
K
=
=
=
=
=
=
5.0V
3.3V
2.5V
1.8V
1.5V
1.2V
TH PIN
LENGTH
Enable
N
N = Negative
Blank = Positive
-
TERMINATION
6
S
6 = 3.7mm
Blank = 5mm
default
S = SMT Termination
(Consult with Factory)
Blank = (TH) thru-hole
1) For Through Hole 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)
2) For SMT termination:
- Recommended surface mount pad ∅ = 0.11 [2.79] ± 0.005 [0.13] (in [mm])
Please call 1-888-41-ASTEC for further inquiries or visit
us at www.astecpower.com
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
SHEET 20 OF 20