User's Manual

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Address : 1879 Lundy Ave, ste. 138, San Jose, CA 95131
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地址：天津市华苑产业区海泰西路 18 号西 3B-202（300384）
12
4.5.2 Internal Reset Circuit:
Notes:
- R
PU
ranges from 30K ohm to 50K ohm internally.
- R
RST
should be from 1K ohm to 10K ohm
4.6 External LPO Input Circuit
An optional low power oscillator input may be added to allow deep sleep and sniff modes.
13.5
11.6
1 GPIO1
2 GPIO2
3 GPIO3
4 GPIO4
5 GPIO5
6 GPIO6
7 GND
TXD 14
RXD 13
RTS 12
CTS 11
RESET 10
BOOT0 9
VIN 8
18 GPS ANT
17 GPIO7
16 SYSCLK
15 LPO
LPO Parameters:
Frequency: 32.768 KHz
Tolerance: 150 ppm
Voltage Levels:
Low: 0.5 V
High: 1.8 V
Input Capacitance: 2.5 pF maximum
Configurations:
See configuration guide:
UseExtLPO
AllowSniff
Ext 32.768 KHz Clock Input (LPO)