Smart Module Series
SC606T Series Hardware Design
SC606T_Series_Hardware_Design 38 / 116
3.1 V
Voltage
3.8 V
Input current
3 A
Figure 3: Voltage Drop Sample
To decrease voltage drop, a bypass capacitor of about 100 µF with low ESR (0.7
Ω) should be used for
VBAT pins, and multi-layer ceramic chip capacitor (MLCC) arrays should also be added for their ultra-low
ESR. It is recommended to use three ceramic capacitors (100 nF, 33 pF, 10 pF) to compose each MLCC
array and place these arrays close to the VBAT/VDD_RF/VPH_PWR pins separately. The width of the
VBAT trace should be no less than 3 mm. In principle, the longer the VBAT trace is, the wider it should be.
In addition, in order to get a stable power source, it is suggested to place a 2000 W TVS as close to the
VBAT pins as possible to increase voltage surge withstand capability. The following figure shows the
structure of the power supply.
Module
VPH_PWR
VBAT
VBAT
C1
100
μ
F
C6
100 nF
C7
C8
+
C2
100 nF
C3
33 pF
C4
D1
VDD_RF
VPH_PWR
C10
C11
C12
33 pF
33 pF 10 pF
10 pF
10 pF
100 nF
Figure 4: Star Structure of Power Supply
3.4.3. Reference Design for Power Supply
A good power design for the module is essential, as the performance of the module largely depends on
the capacity and reliability of the power supply. The power supply of the module should be able to provide
a sufficient current of at least 3 A. It is recommended to use a battery to supply power for the module, and
that if not using a battery, add a voltage regulator. In the latter case, if the voltage drop is not too much,
use a low dropout regulator (LDO); otherwise, use a buck converter instead.
