pth03010 Astec Powe, pth03010 Datasheet - Page 11

• Manufacturer Part Number: pth03010
• Description: Pth03020 3.3vin Single
• Manufacturer: Astec Powe

9. Use in a Manufacturing Environment
9.1 Recommended Land Pattern
It is recommended that the customer uses a solder mask defined
land pattern similar to that shown in Figures 13 and 13.
Power pin connection should utilize four or more vias to the interior
power plane of 0.025 (0.63) I.D. per input, ground and output pin (or
the electrical equivalent).
As a surface-mount power component, interconnection to internal
power planes will typically be required. This is accomplished by
placing a number of vias between the SMT pad and the relevant
plane. the number and exact location of these vias should be
determined based on electrical resistivity, current flow and thermal
requirements.
Figure 13 - Recommended Land Pattern (Through - Hole Model)
Figure 14 - Recommended Land Pattern (Surface-Mount Model)
(2.03)
(2.03)
0.080
0.080
Recommended
keep Out Area
Recommended
keep Out Area
0.125 (3.18)
0.125 (3.18)
2
2
1
1
(12.70)
(12.70)
0.125 (3.18)
0.125 (3.18)
0.500
0.500
10
10
3
3
1.535 (38.99)
1.535 (38.99)
4
4
9
9
File Name: an_pth03020.pdf Rev (05): 21 Dec 2005
5
5
8
8
0.625 (15.88)
0.625 (15.88)
ø
ø
Paste screen opening: 0.80 (2.03 to 0.85 (2.16)
Paste screen thickness: 0.006 (0.150
0.055 (1.40) 10 Places
0.085 (2.16) 10 Places
7
6
7
6
(2.03)
(19.05)
(2.03)
(19.05)
0.080
0.750
0.080
0.750
(23.11)
(23.11)
0.910
0.910
10. Auto-Track™
10.1 Auto-Track™ Function
The Auto-Track™ function is unique to the PTH family, and is
available with the all “Point-of-Load Alliance” (POLA) products. Auto-
Track was designed to simplify the amount of circuitry required to
make the output voltage from each module power up and power
down in sequence. The sequencing of two or more supply voltages
during power up is a common requirement for complex mixed-signal
applications, that use dual-voltage VLSI ICs such as DSPs, micro-
processors, and ASICs.
10.2 How Auto-Track™ Works
Auto-Track™ works by forcing the module’s output voltage to follow
a voltage presented at the Track control pin. This control range is
limited to between 0 V and the module’s set-point voltage. Once the
track-pin voltage is raised above the set-point voltage, the module’s
output remains at its set-point
2.5 V regulator is at 1 V, the regulated output will be 1 V. But if the
voltage at the Track pin rises to 3 V, the regulated output will not go
higher than 2.5 V.
As the regulated output from the module simply follows the voltage
at the Track pin, it is able to ‘track’ virtually any voltage source
during the power-up sequence
externally generated master ramp waveform, or the output voltage
from another power supply circuit
is also provided with an internal RC charge circuit that can produce a
compatible voltage ramp from the input source voltage.
10.3 Typical Application
The simplest implementation of Auto-Track™ is to connect the Track
control pins of two or more compliant PTH modules together. This
forces the Track pins of the modules to follow the same collective
internal RC ramp waveform, and also allows them to be controlled
through a single transistor or switch.
To initiate a power-up sequence, it is recommended that the Track
control be first pulled to ground potential. This should be done at or
before input power is applied to the modules, and then held for at
least 20 ms
complete their internal soft-start initialization. Applying a logic level
high signal to the circuit’s ON/0FF Control turns Q1 on and applies a
ground signal to the Track pins. After completing their internal soft-
start intialization, the output of all modules will remain at zero volts
while Q1 is on.
20 ms after a valid input voltage has been applied to the modules,
Q1 may be turned off. This allows the track control voltage to
automatically rise toward to the modules' input voltage. During this
period the output voltage of each module will rise in unison with
other modules, to its respective set-point voltage.
Figure 16 shows the output voltage waveforms from the circuit of
Figure 15 after the ON/OFF Control is set from a high to a low-level
voltage. The waveforms, V
from the two power modules, U1 (3.3 V) and U2 (2.0 V) respectively.
V
simultaneous power-up characteristic.
Application Note 151
o
1 and V
www.artesyn.com
o
2 are shown rising together to produce the desired
(4)
thereafter. This brief period gives the modules time to
o
1 and V
(1)
(2)
. As an example, if the Track pin of a
. This can be the rising voltage of an
(3)
o
. For convenience, each Track pin
2 represent the output voltages
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