APXH003A0X-SRZ_0910 Datasheet, PDF (14/23 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
Rtrim is the external resistor in kΩ
Vo is the desired output voltage.
Table 1 provides Rtrim values required for some
common output voltages.
Table 1
V_{O, set} (V)
0.6
1.0
1.2
1.5
1.8
2.5
3.3
Rtrim (KΩ)
Open
3.0
2.0
1.333
1.0
0.632
0.444
By using a ±0.5% tolerance trim resistor with a TC of
±25ppm, a set point tolerance of ±1.5% can be
achieved as specified in the electrical specification.
The POL Programming Tool available at
www.lineagepower.com under the Design Tools
section, helps determine the required trim resistor
needed for a specific output voltage.
VIN +
ON/OFF
VO+
SENSE
TRIM
LOAD
Rtrim
GND
Figure 41. Circuit configuration for programming
output voltage using an external resistor.
Remote Sense
The Pico TLynx^TM 3A modules have a Remote Sense
feature to minimize the effects of distribution losses by
regulating the voltage at the SENSE pin. The voltage
between the SENSE pin and VOUT pin must not
exceed 0.5V. Note that the output voltage of the
module cannot exceed the specified maximum value.
This includes the voltage drop between the SENSE
and Vout pins. When the Remote Sense feature is not
being used, connect the SENSE pin to the VOUT pin.
Voltage Margining
Output voltage margining can be implemented in the
Pico TLynx^TM 3A modules by connecting a resistor,
R_margin-up, from the Trim pin to the ground pin for
margining-up the output voltage and by connecting a
resistor, R_margin-down, from the Trim pin to output pin for
margining-down. Figure 42 shows the circuit
configuration for output voltage margining. The POL
Programming Tool, available at
www.lineagepower.com under the Design Tools
section, also calculates the values of R_margin-up and
R_margin-down for a specific output voltage and % margin.
Please consult your local Lineage Power technical
representative for additional details.
Vo
Rmargin-down
MODULE
Q2
Trim
Rmargin-up
Rtrim
Q1
GND
Figure 42. Circuit Configuration for margining
Output voltage
Monotonic Start-up and Shutdown
The Pico TLynx^TM 3A modules have monotonic start-
up and shutdown behavior for any combination of
rated input voltage, output current and operating
temperature range.
Startup into Pre-biased Output
The 5.5V Pico TLynx^TM 6A modules can start into a
prebiased output as long as the prebias voltage is 0.5V
less than the set output voltage. Note that prebias
operation is not supported when output voltage
sequencing is used.
Output Voltage Sequencing
The Pico TLynx^TM modules include a sequencing
feature, EZ-SEQUENCE that enables users to
implement various types of output voltage sequencing
in their applications. This is accomplished via an
additional sequencing pin. When not using the
sequencing feature, either tie the SEQ pin to VIN or
leave it unconnected.
When an analog voltage is applied to the SEQ pin, the
output voltage tracks this voltage until the output
reaches the set-point voltage. The final value of the
SEQ voltage must be set higher than the set-point
voltage of the module. The output voltage follows the
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