APXH003A0X-SRZ_0910 Datasheet, PDF (11/23 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
Test Configurations
TO OSCILLOSCOPE
LTEST
1μH
CURRENT PROBE
VIN(+)
CS 1000μF
Electrolytic
E.S.R.<0.1Ω
@ 20°C 100kHz
CIN
2x100μF
Tantalum
COM
NOTE: Measure input reflected ripple current with a simulated
source inductance (LTEST) of 1μH. Capacitor CS offsets
possible battery impedance. Measure current as shown
above.
Figure 31. Input Reflected Ripple Current Test
Setup.
COPPER STRIP
Vo+
0.1u F
10uF
RES IS TI VE
LOAD
COM
SCOPE USING
BNC SOCKET
GROUND PLANE
NOTE: All voltage measurements to be taken at the module
terminals, as shown above. If sockets are used then
Kelvin connections are required at the module terminals
to avoid measurement errors due to socket contact
res is ta nc e.
Figure 32. Output Ripple and Noise Test Setup.
Rdistribution Rcontact
VIN(+)
VO
Rcontact Rdistribution
VIN
VO
RLOAD
Rdistribution Rcontact
COM COM
Rcontact Rdistribution
NOTE: All voltage measurements to be taken at the module
terminals, as shown above. If sockets are used then
Kelvin connections are required at the module terminals
to avoid measurement errors due to socket contact
resistance.
Figure 33. Output Voltage and Efficiency Test
Setup.
Efficiency η =
VO. IO
VIN. IIN
x 100 %
Design Considerations
Input Filtering
The Pico TLynx^TM 3A module should be connected
to a low ac-impedance source. A highly inductive
source can affect the stability of the module. An
input capacitance must be placed directly adjacent
to the input pin of the module, to minimize input
ripple voltage and ensure module stability.
To minimize input voltage ripple, low-ESR ceramic
capacitors are recommended at the input of the
module. Figure 34 shows the input ripple voltage for
various output voltages at 3A of load current with 1x22
µF or 2x22 µF ceramic capacitors and an input of 5V.
Figure 35 shows data for the 3.3Vin case, with 1x22µF
or 2x22µF of ceramic capacitors at the input.
60
50
40
30
20
1x22uF
10
2x22uF
0
0.5
1
1.5
2
2.5
3
3.5
Output Voltage (Vdc)
Figure 34. Input ripple voltage for various output
voltages with 1x22 µF or 2x22 µF ceramic
capacitors at the input (3A load). Input voltage is
5V.
60
50
40
30
20
1x22uF
10
2x22uF
0
0.5
1
1.5
2
2.5
3
Output Voltage (Vdc)
Figure 35. Input ripple voltage in mV, p-p for
various output voltages with 1x22 µF or 2x22 µF
ceramic capacitors at the input (3A load). Input
voltage is 3.3V.
LINEAGE POWER
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