Datasheet

PM8903A demonstration board PM8903A
28/33 Doc ID 024147 Rev 1
7.1.1 Power input (V
IN
)
Connect a power supply to connectors J4(VIN) and J5(GND) on the demonstration board to
provide voltage on the power input pins of both devices. Input voltage can range from 2.8 V
to 6 V bus.
If the voltage is between 2.9 V and 5.5 V, it can also supply the signal input pins of both
devices (through the V
CC
pin). In this case, make sure that resistors R2/R20 are NM (not
mounted) and mount 0 Ω resistors on R1/R19 locations.
7.1.2 Signal input (V
CC
)
The controller is usually supplied separately from the power stage through the V
CC
input
pins.
Connect a power supply to connector J2 (pin one is VC and pin two is GND) on the
demonstration board to provide voltage on the signal input pins of both devices. Supply
voltage can range from 2.9 V to 5.5 V.
7.1.3 Output (V
OUT
)
On the standard demonstration board, the output voltage is programmed to be 1.5 V, but it
can be easily changed mounting one of the values suggested in
Tabl e 9 .
Select the R
OS
(R16/R34) resistor value with the following formula in order to program a
custom value for the output voltage of each device.
where:
● V
OUT
is the desiderated output voltage
● V
REF
is the internal voltage reference (0.6 V)
● R
FB
resistor, on the demonstration board, is the sum of two resistors (R14/R15 for
device U1 and R32/R33 for device U2) and has a total value of 3.3 kΩ.
Table 9. Typical R
OS
resistors (R16/R34)
Programmed output voltage Resistor value
0.6 V NM
0.8 V 10 kΩ
1.0 V 4.9 kΩ
1.2 V 3.3 kΩ
1.5 V 2.2 kΩ
1.8 V 1.65 kΩ
2.5 V 1 kΩ
R
OS
R
FB
V
REF
V
OUT
V
REF
–
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