Yeoman CHEN
CHECKED BY
Eden LIU
DRAWN BY
A2
2016/11/11
3
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Quectel Wireless Solutions
PROJECT
SIZE
SHEET
DATE
OF 10
VER
C
EC25
TITLE
VDD_1V8=(R310/R312+1)*1.207=1.8V
VDD_3.3V=(R305/R308+1)*1.207=3.3V
Power Supply Design
DC-DC Application
It is used when the input voltage is above 7V. Use a DC-DC converter to convert a high input voltage
e.g. DC12V IN
DC-DC
DC 5V OUT
LDO
DC 3.8V 2.0A
LDO
DC 1.8V
LDO
DC 3.3V
VBAT=(R301/R306+1)*1.24=3.88V
Recommended load current is greater than 10mA.
Codec
Supply Power for FC20 and SGMII
VDD3V3=(R314/R317+1)*1.24=3.3V
LDO
FC20
DC 3.3V 1.2A
SGMII
EC25
into 5V output, and then the LDOs will generate 3.8V, 3.3V and 1.8V typical voltages.
LDO Application
It is used when the input voltage is below 7V.
Note:
1. Recommended load current of MIC29302WU is greater than 10mA.
Notes:
Close to the module VBAT pins.
Notes:
2. VBAT should be routed in star mode to VBAT_BB and VBAT_RF pins.
VBAT Design
Connect to VBAT_BB pins.
Connect to VBAT_RF pins.
1. The power supply must be able to provide sufficient current up to 2A or more.
3. The recommended operating voltage of VBAT is 3.3V~4.3V.
Supply Power for PCM Codec
Reference Design
Note 2
2. RC circuit, which is assembled with R318 and C327, is used to delay the start-up of MOSFET switch circuit.
Note 1
1 IN
3 EN
5
OUT
4
BP
2
GND
U303
SGM2019-ADJYN5G/TR
C320
4.7uF
R310
39K_1%
R312
75K_1%
C318
100nF
C321
100nF
C322
33pF
C319
1uF
C315
4.7uF
R305
73.2K
1%
R308
42.2K
1%
C316
100nF
C313
1uF
C314
100nF
1 IN
3 EN
5
OUT
4
BP
2
GND
U302
SGM2019-ADJYN5G/TR
C317
33pF
R307
100K
R304
0R
R311
100K
R309
0R
+
C323
470uF
1
EN
2 IN
3
GND
4
OUT
5
ADJ
U304
MIC29302WU
C324
100nF
C326
100nF
+
C325
470uF
R314
75K
1%
R317
47K
1%
R313
51K
R315
330R
R316
10K
G
S
D
Q302
SI2333
C327
100nF
R318
100K
Q303
DTC043ZE
+
C311
470uF
1
EN
2 IN
3
GND
4
OUT
5
ADJ
U301 MIC29302WU
C312
100nF
C310
100nF
+
C309
470uF
R301
100K
1%
R306
47K
1%
R302
330R
D302
TVS
Q301
DTC043ZEBTL
R303
51K
+
C301
100uF
D301
PZ3D4V2H
C302
100nF
C303
33pF
C304
10pF
C306
100nF
C307
33pF
C308
10pF
+
C305
100uF
VDD_1V8
VDD_3.3V
[2,3] DC_5V
[2,3] DC_5V
[2,3] CODEC_POWER_EN
[2,3] DC_5V
VDD3V3
[1] PM_ENABLE
[9]
VDD3V3_FC20
[2,3] DC_5V
VBAT
[2] VBAT_EN
[1,3,10]
VBAT
[1,3,10]
VBAT
VBAT
[2,3] CODEC_POWER_EN
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