![SimCom SIM548C HD V1.01 Скачать руководство пользователя страница 24](http://html1.mh-extra.com/html/simcom/sim548c-hd-v1-01/sim548c-hd-v1-01_hardware-design_1274794024.webp)
SIM548C Hardware Design
The circuit design of the power supply depends strongly on the power source where this power is
drained. The following figure is the reference design of +5V input source power supply. The
designed output for the power supply is 4V, thus a linear regulator can be used. If there’s a big
difference between the input source and the desired output (VBAT), a switching converter power
supply will be preferable because of its better efficiency especially with the 2A peak current in
burst mode of the module.
The single 3.6V Li-Ion cell battery type can be connected to the power supply of the module
VBAT directly. But the Ni_Cd or Ni_MH battery types must be used carefully, since their
maximum voltage can rise over the absolute maximum voltage for the module and damage it.
Figure
3
: Reference circuit of the source power supply input
The following figure is the VBAT voltage ripple wave at the maximum power transmit phase, the
test condition is VBAT=4.0V, VBAT maximum output current =2A, C
A
=100µF tantalum
capacitor (ESR=0.7
Ω
) and C
B
=1µF.
Figure
4: VBAT voltage drop during transmit burst
SIM548C_HD_V1.01
09.05.2008
24
Содержание SIM548C HD V1.01
Страница 1: ...Hardware Design SIM548C_HD_V1 01 ...