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12v microtlynx, 12a: non-isolated dc-dc power modules, Data sheet – GE Industrial Solutions 12V MicroTLynx 12A User Manual

Page 18: Module

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GE

Data Sheet

12V MicroTLynx

TM

12A: Non-Isolated DC-DC Power Modules

4.5Vdc –14Vdc input; 0.69Vdc to 5.5Vdc output; 12A Output Current

May 2, 2013

©2013 General Electric Company. All rights reserved.

Page 18

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.

The Tunable Loop

TM

allows the user to externally adjust the

voltage control loop to match the filter network connected to
the output of the module. The Tunable Loop

TM

is implemented by

connecting a series R-C between the SENSE and TRIM pins of the
module, as shown in Fig. 48. This R-C allows the user to
externally adjust the voltage loop feedback compensation of the
module.

Recommended values of R

TUNE

and C

TUNE

for different output

capacitor combinations are given in Tables 2 and 3. Table 2

shows the recommended values of R

TUNE

and C

TUNE

for different

values of ceramic output capacitors up to 940 F that might be
needed for an application to meet output ripple and noise

requirements. Selecting R

TUNE

and C

TUNE

according to Table 2 will

ensure stable operation of the module

Figure. 48. Circuit diagram showing connection of R

TUME

and

C

TUNE

to tune the control loop of the module.

In applications with tight output voltage limits in the presence of
dynamic current loading, additional output capacitance will be

required. Table 3 lists recommended values of R

TUNE

and C

TUNE

in

order to meet 2% output voltage deviation limits for some
common output voltages in the presence of a 6A to 12A step
change (50% of full load), with an input voltage of 12V.

Please contact your GE 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 12V.


Table 2. General recommended values of of R

TUNE

and C

TUNE

for Vin=12V and various external ceramic capacitor
combinations.

Co

1x47

μF 2x47μF 4x47μF 10x47μF 20x47μF

R

TUNE

470 270 150 150 150

C

TUNE

1000pF 3300pF 4700pF 8200pF 12nF

Table 3. Recommended values of R

TUNE

and C

TUNE

to obtain

transient deviation of 2% of Vout for a 6A step load with

Vin=12V.

Vo

5V

3.3V

2.5V

1.8V

1.2V

0.69V

Co 4x47μF

1x47

μF

+

330

μF

Polymer

2x47

μF

+

330

μF

Polymer

6x47

μF +

330

μF

Polymer

6x47

μF +

2x330

μF

Polymer

4x47

μF +

6x330

μF

Polymer

R

TUNE

270 220 220 220 150 150

C

TUNE

3300pF 4700pF 6800pF

18nF 33nF 100nF

ΔV

91mV 60mV 47mV 35mV 23mV 12mV

MODULE

VOUT

SENSE

TRIM

GND

RTUNE

CTUNE

RTrim

C O