APXH003A0X-SRZ_0910 Datasheet, PDF (12/23 Pages) Lineage Power Corporation – Pico TLynxTM 3A: Non-Isolated DC-DC Power Modules

Data Sheet
October 8, 2009
Pico TLynx^TM 3A: Non-isolated DC-DC Power Modules
2.4 – 5.5Vdc input; 0.6Vdc to 3.63Vdc output; 3A output current
Output Filtering
The Pico TLynx^TM 3A modules are designed for low
output ripple voltage and will meet the maximum
output ripple specification with 0.1 µF ceramic and 10
µF ceramic capacitors at the output of the module.
However, additional output filtering may be required by
the system designer for a number of reasons. First,
there may be a need to further reduce the output ripple
and noise of the module. Second, the dynamic
response characteristics may need to be customized
to a particular load step change.
To reduce the output ripple and improve the dynamic
response to a step load change, additional
capacitance at the output can be used. Low ESR
ceramic and polymer capacitors are recommended to
improve the dynamic response of the module. Figure
36 provides output ripple information for different
external capacitance values at various Vo and for load
currents of 3A while maintaining an input voltage of
5V. Fig 37 shows the performance with a 3.3V input.
For stable operation of the module, limit the
capacitance to less than the maximum output
capacitance as specified in the electrical specification
table. Optimal performance of the module can be
achieved by using the Tunable Loop feature described
later in this data sheet.
30
25
20
1x10uF External Cap
15
1x47uF External cap
2x47uF External Cap
4x47uF external Cap
10
5
0
0.5
1
1.5
2
2.5
3
3.5
Output Voltage(Volts)
Figure 36. Output ripple voltage for various output
voltages with external 1x10 µF, 1x47 µF, 2x47 µF or
4x47 µF ceramic capacitors at the output (3A load).
Input voltage is 5V.
20
15
10
1x10uF External Cap
1x47uF External cap
2x47uF External Cap
5
4x47uF external Cap
0
0.5
1
1.5
2
2.5
3
Output Voltage(Volts)
Figure 37. Output ripple voltage for various output
voltages with external 1x10 µF, 1x47 µF, 2x47 µF or
4x47 µF ceramic capacitors at the output (3A load).
Input voltage is 3.3V.
Safety Considerations
For safety agency approval the power module must be
installed in compliance with the spacing and
separation requirements of the end-use safety agency
standards, i.e., UL 60950-1, CSA C22.2 No. 60950-1-
03, and VDE 0850:2001-12 (EN60950-1) Licensed.
For the converter output to be considered meeting the
requirements of safety extra-low voltage (SELV), the
input must meet SELV requirements. The power
module has extra-low voltage (ELV) outputs when all
inputs are ELV.
The input to these units is to be provided with a fast-
acting fuse with a maximum rating of 5A in the positive
input lead.
Feature Descriptions
Remote On/Off
The Pico TLynx^TM 3A modules feature an On/Off pin
for remote On/Off operation. Two On/Off logic options
are available. In the Positive Logic On/Off option,
(device code suffix “4”- see Ordering Information), the
module turns ON during a logic High on the On/Off pin
and turns OFF during a logic Low. With the Negative
Logic On/Off option, (no device code suffix, see
Ordering Information), the module turns OFF during
logic High and ON during logic Low. The On/Off signal
is always referenced to ground. For either On/Off logic
option, leaving the On/Off pin disconnected will turn
the module ON when input voltage is present.
For positive logic modules, the circuit configuration for
using the On/Off pin is shown in Figure 38. When the
external transistor Q1 is in the OFF state, Q2 is ON,
the internal PWM Enable signal is pulled low and the
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