Automotive Module Series
AG525R-GL QuecOpen
Hardware Design
AG525R-GL_QuecOpen_Hardware_Design 43 / 104
Table 7: VBAT and GND Pins
Pin Name
Pin No.
Description
Min.
Typ.
Max.
Unit
VBAT_BB
241, 242, 244
Power supply for the
module’s baseband part
3.3 3.8 4.3
V
VBAT_RF
109, 111, 112, 114
Power supply for the
module’s RF part
3.3 3.8 4.3
V
GND
12, 18, 26, 33, 42, 86, 92, 98, 115, 117, 118, 120, 121, 124–131,133–135, 137, 138,
140, 141, 144–151,153, 155, 156, 158, 159, 160, 162, 164, 165, 167, 168,
171–174,176, 177, 180, 182, 183, 185, 186, 189, 191, 192, 194, 195, 198, 199,
201–203, 206, 208, 209, 211, 212, 215, 217, 218, 220, 221, 230, 232, 233, 234, 237,
240, 307–400
3.6.2. Decrease Voltage Drop
The power supply range of the module is from 3.3 to 4.3 V. Please make sure that the input voltage will
never drop below 3.3 V. The following figure shows the voltage drop during burst transmission in 2G
network. The voltage drop will be less in 3G and 4G networks.
Figure 7: Power Supply Limits during Burst Transmission
To decrease voltage drop, a bypass capacitor of about 100 µF with low ESR should be used, and a
multi-layer ceramic chip capacitor (MLCC) array should also be reserved due to its low ESR. It is
recommended to use three ceramic capacitors (100 nF, 33 pF, 10 pF) for composing the MLCC array, and
place these capacitors close to VBAT pins. DC_3V8 from an external application has to be a single
voltage source and can be expanded to two sub paths with star structure. The width of VBAT_BB trace
should be no less than 1 mm. The width of VBAT_RF trace should be no less than 2 mm. In principle, the
longer the VBAT trace is, the wider it will be.
In addition, in order to get a stable power source, it is suggested to use high power TVS diode to prevent
static electricity, and place them as close to the VBAT pins as possible. The following figure shows a
reference design of VBAT power supply pins.
