User's Manual

Smart Machine Smart Decision
SIM7600SA-H_User Manual_V1.00 2017-10-11
3.1.1 Power Supply Design Guide
Make sure that the voltage on the VBAT pins will never drop below 3.4V, even during a transmit
burst, when current consumption may rise up to 2A. If the voltage drops below 3.4V, the RF
performance may be affected.
Note: If the power supply for VBAT pins can support up to 2A, using a total of more than 300uF
capacitors is recommended, or else users must using a total of 1000uF capacitors typically, in
order to avoid the voltage drop is more than 300mV.
Some multi-layer ceramic chip (MLCC) capacitors (0.1/1uF) with low ESR in high frequency band
can be used for EMC.
These capacitors should be put as close as possible to VBAT pads. Also, users should keep VBAT
trace on circuit board wider than 2 mm to minimize PCB trace impedance. The following figure
shows the recommended circuit.
VBAT
VBAT
VBAT
VBAT
62
63
38
39
Cf
Ce
100nF
100uF
61
64
GND
GND
37
40
GND
GND
MODULE
Cb
Cc
FB101
5.1V
500mW
100uF
1uF
VBAT
Ca
100uF
Cd
100uF
Figure 6: Power supply application circuit
In addition, in order to guard for over voltage protection, it is suggested to use a zener diode with
5.1V reverse zener voltage and more than 500mW power dissipation.
Table 7: Recommended Zener diode list
No.
Manufacturer
Part Number
Power dissipation
Package
1
On semi
MMSZ5231BT1G
500mW
SOD123
2
Prisemi
PZ3D4V2H
500mW
SOD323
3
Vishay
MMSZ4689-V
500mW
SOD123
4
Crownpo
CDZ55C5V1SM
500mW
0805