Ret-3570lp user manual, 10 hardware interface – RoyalTek RET-3570LP User Manual
Page 12
RoyalTek Confidential
10
RET-3570LP User Manual
1.10 Hardware interface
Interface Pin Number:
Pin # Signal Name
I/O Description
Characteristics
1
V_GPS_3V3
I
DC Supply Voltage input
DC +3.3V
±5%
2 GND
G
Ground
Reference
Ground
3 BOOT
I
Boot
mode
V
V
V
V
V
IL
IH
855
.
0
0.3V
-
15
.
3
995
.
1
≤
≤
≤
≤
4 RXA
I
Serial
port
A
V
V
V
V
V
IL
IH
855
.
0
0.3V
-
15
.
3
995
.
1
≤
≤
≤
≤
5 TXA
O
Serial
port
A
V
V
V
V
V
OL
OH
715
.
0
85
.
2
375
.
2
≤
≤
≤
6
TXB
O Serial port B
V
V
V
V
V
OL
OH
715
.
0
85
.
2
375
.
2
≤
≤
≤
7
RXB
I
Serial port B
V
V
V
V
IL
IH
855
.
0
0.3V
-
15
.
3
995
.
1
≤
≤
≤
≤
8 N.C
9 RF_ON
O
Indicates power state of RF
part
V
V
V
V
OL
OH
0
;
85
.
2
=
=
10 GND
G
Ground
Reference
Ground
11
AUDIO_R
O Audio right channel output
AFL
V
Output voltage 66mV(typical) ~75mV(max)
AFL
R
Output resistance 50Ω(min) ~ 100Ω
12
AUDIO_L
O Audio Left channel output
AFL
V
Output voltage 66mV(typical) ~75mV(max)
AFL
R
Output resistance 50Ω(min) ~ 100Ω
13 GND
G
Ground
Reference
Ground
14 FM_RF_IN I
FM antenna input
FM antenna input