Data Sheet
Pico TLynxTM 6A: Non-isolated DC-DC Power Modules
May 20, 2009
2.4 – 5.5Vdc input; 0.6Vdc to 3.63Vdc output; 6A output current
SEQUENCETM feature must be disabled. For
additional guidelines on using the EZ-SEQUENCETM
feature please refer to Application Note AN04-008
“Application Guidelines for Non-Isolated Converters:
Guidelines for Sequencing of Multiple Modules”, or
contact the Lineage Power technical representative for
additional information.
In applications with tight output voltage limits in the
presence of dynamic current loading, additional output
capacitance will be required. Tables 3 and 5 lists
recommended values of RTUNE and CTUNE in order to
meet 2% output voltage deviation limits for some
common output voltages in the presence of a 3A to 6A
step change (50% of full load), with an input voltage of
5V or 3.3V respectively
Tunable LoopTM
The 5V Pico TLynxTM 6A modules have a new feature
that optimizes transient response of the module called
Please contact your Lineage Power technical
representative to obtain more details of this feature as
well as for guidelines on how to select the right value of
external R-C to tune the module for best transient
performance and stable operation for other output
capacitance values or input voltages other than 5V.
Tunable LoopTM
.
External capacitors are usually added to the output of
the module for two reasons: to reduce output ripple and
noise (see Figures 36 and 37) and to reduce output
voltage deviations from the steady-state value in the
presence of dynamic load current changes. Adding
external capacitance however affects the voltage control
loop of the module, typically causing the loop to slow
down with sluggish response. Larger values of external
capacitance could also cause the module to become
unstable.
Table 2. General recommended values of of RTUNE
and CTUNE for Vin=5V and various external ceramic
capacitor combinations.
Cext
1x47μF 2x47μF 4x47μF 6x47μF 10x47μF 20x47μF
RTUNE
47
47
47
33
33
33
CTUNE 4700pF 10nF
33nF
47nF
56nF
68nF
The Tunable LoopTM allows the user to externally adjust
the voltage control loop to match the filter network
connected to the output of the module. The Tunable
LoopTM is implemented by connecting a series R-C
between the SENSE and TRIM pins of the module, as
shown in Fig. 44. This R-C allows the user to externally
adjust the voltage loop feedback compensation of the
module.
Table 3. Recommended values of RTUNE and CTUNE to
obtain transient deviation of ≤2% of Vout for a 3A
step load with Vin=5V.
Vo
3.3V
2.5V
1.8V
1.2V
0.6V
1 x 47μF 6 x 47μF
Co
3 x 47μF 4 x 47μF 5 x 47μF + 330uF + 330uF
Polymer Polymer
RTUNE
CTUNE
ΔV
100
15nF
58mV
56
47
33
33
VOUT
18nF
45mV
27nF
34mV
47nF
24mV
39nF
12mV
SENSE
RTUNE
Table 4. General recommended values of of RTUNE
and CTUNE for Vin=3.3V and various external ceramic
capacitor combinations.
C O
MODULE
CTUNE
Co
1x47μF 2x47μF 4x47μF 6x47μF 10x47μF 20x47μF
TRIM
RTUNE
47
47
47
33
33
33
CTUNE 10nF
15nF
39nF
47nF
68nF
82nF
RTrim
GND
Table 5. Recommended values of RTUNE and CTUNE to
obtain transient deviation of ≤2% of Vout for a 3A
step load with Vin=3.3V.
Figure. 44. Circuit diagram showing connection of
RTUME and CTUNE to tune the control loop of the
module.
Vo
2.5V
1.8V
1.2V
0.6V
Recommended values of RTUNE and CTUNE for different
output capacitor combinations are given in Tables 2, 3,
4 and 5. Tables 2 and 4 shows the recommended
values of RTUNE and CTUNE for different values of
ceramic output capacitors up to 940uF that might be
needed for an application to meet output ripple and
noise requirements. Selecting RTUNE and CTUNE
according to Tables 3 or 5 will ensure stable operation
of the module.
2 x 47μF +
330uF
Polymer
2 x 330uF
Polymer
Co
6 x 47μF 6 x 47μF
RTUNE
CTUNE
ΔV
33
33
33
33
47nF
46mV
47nF
33mV
68nF
24mV
220nF
12mV
LINEAGE POWER
16
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