UNICORECOMM UM220-IV M0 User manual

WWW.UNICORECOMM.COM
Data subject to change without notice.
Copyright© 2009-2020, Unicore Communications, Inc.
REFERENCE DESIGN
HARDWARE
GNSS Positioning Module
UM220-IV M0

I
Revision History
Version
Revision History
Date
Ver. 1.0
HW reference design, primary
Aug. 2018
Ver. 1.1
Change the symbol of V_BCKP from button
battery to power
TXD connects 1K resistance in series
Aug. 2019
R1.2
Update Copyright time
Apr. 2020
Disclaimer
Information in this document is subject to change without notices and does not
represent a commitment on the part of Unicore Communication, Inc. No part of this
manual may be reproduced or transmitted in any form or by any means, electronic or
mechanical, including photocopying and recording, for any purpose without the express
written permission of a duly authorized representative of Unicore Communications, Inc.
The information contained within this manual is believed to be true and correct at the
time of publication.
© Copyright 2009-2020 Unicore Communications, Inc. All rights reserved.

UM220-IV M0 Hardware Reference Design
II
Contens
1. Minimum System Reference Circuit.........................................................................................1
2. Reference Circuit Using a Passive Antenna..............................................................................2
3. Attachment................................................................................................................................5

1
1. Minimum System Reference Circuit
Supply 2.8V~3.6V power VCC
Ground all GND pins of the module
Connect RF_IN signal to antenna, note the 50 Ω impedance match on the circuit
Figure 1 Minimum System Reference Circuit
GND
nRESET
RXD
TXD
L1
68nH
GND
C2 100pF
C1 100nF
R2 0
R5 0
GND C10 100nF
VBCKP
VBCKP：1.4V~3.6V
VCC：2.8V~3.6V
GND
GND
C4
10 uF
VCC
GND
C3
100nF
J1
Active Ant
1
2 3 4 5
+3V
TXD
RXD
A1
UM220-IV-M0
nREST
9
NC2 13
TIMEPULSE
4
NC1
5NC3 15
VCC_RF 14
GND 10
RF_IN 11
GND 12 VCC_IO
7
NC6 18
NC4 16
NC5 17 TXD
2
RXD
3
V_BCKP
6
VCC
8
GND
1
GND
C7100nF
C9100nF
C8
100nF
C5
100nF
U1
MAX3232EUE+
DIN1
11
DIN2
10
ROUT1
12 ROUT2
9
DOUT1 14
DOUT2 7
RIN1 13
RIN2 8
V+
2
C1+ 1
C1- 3
C2+ 4
C2- 5 V-
6
VCC
16
GND
15
GND
GND
GND
C6
100nF
GND
GND
GND
J2
DB9
5
9
4
8
3
7
2
6
1
10
11
R3 100
R4 100
R1 1K
Active Low

UM220-IV M0 Hardware Reference Design
2
2. Reference Circuit Using a Passive Antenna
To ensure the system performance, low noise amplifier and filter should be added
between the passive antenna and the module RF_IN
The VCC_RF output of the module is recommended for power supply with LNA
RF wire (Antenna → LNA → SAW → RF_IN), note the impedance matching at 50Ω
Figure 2 Reference Circuit Using a Passive Antenna
A1
UM220-IV-M0
nREST
9
NC2 13
TIMEPULSE
4
NC1
5NC3 15
VCC_RF 14
GND 10
RF_IN 11
GND 12 VCC_IO
7
NC6 18
NC4 16
NC5 17 TXD
2
RXD
3
V_BCKP
6
VCC
8
GND
1
FB1
220@100MHz
VCC_RF
GND C12 100nF
VBCKP
VCC：2.8V~3.6V
VBCKP：1.4V~3.6V
R1 1K
Active Low
R2 0
R5 0
nRESET
GND
RXD
TXD
GND
GND
C6
10 uF
GND
VCC C5
100nF
+3V
TXD
RXD
C9 100nF
C11 100nF
C10
100nF
C7
100nF
U3
MAX3232EUE+
DIN1
11
DIN2
10
ROUT1
12 ROUT2
9
DOUT1 14
DOUT2 7
RIN1 13
RIN2 8
V+
2
C1+ 1
C1- 3
C2+ 4
C2- 5 V-
6
VCC
16
GND
15
GND
GND
GND
C8
100nF GND
GND GND
J2
DB9
5
9
4
8
3
7
2
6
1
10
11
R3 100
R4 100
GND
MAX2659ELT+U1
GND#1 1
GND#2 2
RFIN
3
VCC
4
SHDN#
5
RFOUT 6U2 TA0757A
GND#2 3
OUT
4GND#3 5
GND#1 2 IN
1
L1 6.8nH
C3
1uF
C4
100nF GND GND
C2 100pFC1 100pF
J1
Passive Ant 1
2 3 4 5
GND VCC_RF

3
3. Attachment
Here are two options to avoid module startup abnormality caused by string power.
Option 1
No external pull-up resistor is allowed to connect with the output pin TXD；
Option 2
When the module is not powered on, make sure the IO port connected to the
module is in high resistance state or low level to avoid string power.

www.unicorecomm.com
和芯星通科技（北京）有限公司
Unicore Communications, Inc.
www.unicorecomm.com
Phone: [phone]
Fax: [phone]
[e-mail]
北京市海淀区丰贤东路7号北斗星通大厦三层
F3, No.7, Fengxian East Road, Haidian, Beijing, P.R.China,
100094