ST Teseo-LIV3F User manual

October 2018 UM2231 Rev 4 1/26
1
UM2231
User manual
Teseo-LIV3F GNSS Module - Hardware Manual
Introduction
Teseo-LIV3F is a tiny GNSS module sized 9.7 mm × 10.1 mm × 2.5 mm featuring
STMicroelectronics®positioning receiver Teseo III. It is a standalone positioning receiver
which embeds the new ST GNSS positioning engine capable of receiving signals from
multiple satellite navigation systems, including GPS, Glonass or Beidou, Galileo and QZSS.
It embeds a 16M-Bit serial Flash.
In Figure 1 pinout of the module is represented as follows:
Figure 1. Teseo-LIV3F pinout
www.st.com

Contents UM2231
2/26 UM2231 Rev 4
Contents
1 Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.1 VCC (pin8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2 VBAT (pin6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.3 VCC_IO (pin7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.4 VCC_RF (pin14) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.5 Power supply design reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.6 Current consumption optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2 Reserved (pin15, 18) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3 Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1 I2C (pin16, 17) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
3.2 UART (pin2, 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
4 I/O pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.1 PPS (pin4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.2 Wake_Up (pin5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.3 SYS_RESETn (pin9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.4 RF_IN (pin10) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.5 AntOFF (pin13) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5 Standby modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.1 Software standby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.2 Hardware standby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6 Front ends management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.1 External LNA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.2 Active antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7 Reference schematic and BOM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.1 Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.1.1 Bill of material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

UM2231 Rev 4 3/26
UM2231 Contents
3
8 Layout recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
9 Antenna recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.1 Patch antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.1.1 Antenna on the opposite side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.1.2 Antenna on the same side than Teseo-LIV3F . . . . . . . . . . . . . . . . . . . . 22
9.2 Chip antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
9.3 Remote antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

List of tables UM2231
4/26 UM2231 Rev 4
List of tables
Table 1. Bill of material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Table 2. List of suggested antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Table 3. List of SMD antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Table 4. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

UM2231 Rev 4 5/26
UM2231 List of figures
5
List of figures
Figure 1. Teseo-LIV3F pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Figure 2. Inductor on VCC power line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Figure 3. Teseo-LIV3F minimum connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 4. Output supply filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 5. Power supply filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Figure 6. Example of SMPS to improve current consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Figure 7. UART filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Figure 8. PPS pin filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Figure 9. External LNA control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Figure 10. Active antenna current switch control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 11. Active antenna current sense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 12. General schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 13. Placing parallel component pads on 50 ohms line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 14. Reuse pads of one component on the line bypassing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 15. Layout proposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 16. Antenna vs Teseo-LIV3F placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 17. Antenna on bottom layer and Teseo-LIV3F on top layout example . . . . . . . . . . . . . . . . . . 22
Figure 18. 25×25mm SMD Antenna and LIV3F on same layer example. . . . . . . . . . . . . . . . . . . . . . . 23
Figure 19. Chip Antenna and Teseo-LIV3F on same example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Power UM2231
6/26 UM2231 Rev 4
1 Power
Teseo-LIV3F is supplied by 3 power pins: VCC (pin8), VCC_IO (pin7) and VBAT (pin6).
1.1 VCC (pin8)
VCC is the main supply. VCC limiting values are: 2.1 V - 4.3 V.
At startup or during low power application current can change suddenly. It is important that
supply IC is able to provide this current variation.
Take care that interference on VCC power line could degrade Teseo-LIV3F sensitivity
performance, to avoid that it’s recommended a 27 nH inductor (Murata LQG15HS27NJ02)
as shown in Figure 2: Inductor on VCC power line.
Figure 2. Inductor on VCC power line
The suggested inductor on the VCC power line is able to recover interference coming from
VCC power line.
1.2 VBAT (pin6)
VBAT is the supply for the low power domain backup: backup RAM and RTC.
VBAT can be either connected to VCC or it can be supplied by a dedicated supply always
ON. When VBAT supply is kept ON during low power mode to allow fast recovery of GNSS

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UM2231 Power
24
fix VBAT prevents current flow as soon as VBAT is lower than VCC. It is important when
VBAT is supplied with small battery and especially if battery is not rechargeable.
VBAT range can be from 2.1 V to 4.3 V.
1.3 VCC_IO (pin7)
VCC_IO is 3.3 V.
Figure 3 shows the minimum connection to make Teseo-LIV3F GNSS working.
Figure 3. Teseo-LIV3F minimum connection
1.4 VCC_RF (pin14)
VCC_RF is an output image of VCC with a filtering for LNA or active antenna supply.
It can be filtered to remove high frequency noise as shown in Figure 4.

Power UM2231
8/26 UM2231 Rev 4
Figure 4. Output supply filtering
1.5 Power supply design reference
During prototyping stage, for the first PCBs, it is recommended to plan to have some filtering
components on Teseo-LIV3F power supplies as shown In Figure 5.
Figure 5. Power supply filtering
Inductor size is 0401 (1.0×0.5mm) and capacitors are 0201 (0.6×0.3mm).
In case VCC_IO is separate from VCC, a serial 27nH inductor could also be planned for first
PCBs.

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UM2231 Power
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If VCC and VCC_IO are same supplies, one single capacitor and one single inductor can be
used. If not it is recommended to duplicate the filtering.
1.6 Current consumption optimization
Use of an SMPS at 2.1 V to supply VCC is recommended to optimize current consumption.
Here is an application example with ST1S12GR with an efficiency around 85%.
Figure 6. Example of SMPS to improve current consumption
If VCC_IO is also supplied by an SMPS, this will reach the lowest current consumption.

Reserved (pin15, 18) UM2231
10/26 UM2231 Rev 4
2 Reserved (pin15, 18)
In Teseo-LIV3F pin15 and 18 are reserved.

UM2231 Rev 4 11/26
UM2231 Interfaces
24
3 Interfaces
3.1 I2C (pin16, 17)
Teseo-LIV3F supports I2C slave mode only.
Internal 10 Kpull-up resistor on VCC_IO is present. It is important to avoid having other
pull-up for current leakage in low power mode.
3.2 UART (pin2, 3)
UART is a Universal Asynchronous Receiver/Transmitter that supports much of the
functionality of the industry-standard 16C650 UART.
These UARTs vary from industry-standard 16C650 on some minor points which are:
Receive FIFO trigger levels
The deltas of the modem status signals are not available
1.5 stop bit is not supported
Independent receive clock feature is not supported
During prototyping stage, for the firsts PCBs, it is recommended to plan to have some
filtering components on Teseo-LIV3F UART lines as shown in Figure 7.
Figure 7. UART filtering

I/O pins UM2231
12/26 UM2231 Rev 4
4 I/O pins
4.1 PPS (pin4)
PPS is the time pulse every one second. It can be configured with different condition of
pulses.
During prototyping stage, for the first PCBs, it is recommended to plan to have some filtering
components on Teseo-LIV3F PPS pin as shown in figure
Figure 8. PPS pin filtering
4.2 Wake_Up (pin5)
It is an external interrupt that is used to wake-up Teseo-LIV3F for asynchronous wake-up
during standby software for instance.
It can be activated by a GPIO from host for instance. Wake_Up signal is active high.
4.3 SYS_RESETn (pin9)
It can force a Teseo-LIV3F under reset.
Reset signal is active low.
Host processor must have full control of this pin to guarantee the Teseo-LIV3F’s firmware
upgrade support.
4.4 RF_IN (pin10)
It is the RF input.

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UM2231 I/O pins
24
4.5 AntOFF (pin13)
AntOFF is a GPIO used to switch OFF external LNA or switch OFF current for the active
antenna.
A 10 kΩpull down is necessary to ensure a low level during standby period.

Standby modes UM2231
14/26 UM2231 Rev 4
5 Standby modes
Standby mode, is the mode where only low power backup domain is running. It means
VBAT must always be maintained. It allows to have very low current consumption and fast
GNSS reacquisition at the end of the standby time due to RTC.
Teseo-LIV3F offers 2 different ways of standby:
Hardware standby
Software standby
As IO buffers are not supplied during standby mode, it is important to keep all IO without
external voltage to avoid any current leakage. UART_RX is an exception it can be left high.
5.1 Software standby
Software standby is activated by the binary for periodic standby. More details of how to set it
are in the Software Manual. As HW standby, all supplies are kept ON.
Periodic fixes are from 5 s up to 24 hours between 2 fixes.
It ensures a current below 20 µA on Teseo-LIV3F. Be careful that VCC_RF is ON during this
standby, then in case of active antenna or external LNA, it is important to switch them OFF.
5.2 Hardware standby
This standby is ensured by switching OFF VCC (pin 8) and VCC_IO (pin 7) supplies and
setting SYS_RESETn (pin 9) to 0 V. It can be activated asynchronously from GNSS binary
with one GPIO switching OFF the supplies from a host.
During this standby only VBAT (pin 6) is kept ON.
It ensures a current below 15 µA. During this standby mode VCC_RF (pin 14) is OFF.

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UM2231 Front ends management
24
6 Front ends management
RF input impedance is 50 Ω.
6.1 External LNA
External LNA means a passive antenna used with an LNA on the same PCB as Teseo-
LIV3F module. To optimize power consumption during low power mode if needed, the LNA
should have an enable pin compatible with VCC_IO to be switched OFF/ON.
Here is a block diagram describing the connection.
Figure 9. External LNA control

Front ends management UM2231
16/26 UM2231 Rev 4
6.2 Active antenna
To optimize the current during low power operating mode, the active antenna can be used
with a switch to cut the current flow.
Figure 10. Active antenna current switch control
To improve the functionality, a current limiter could be used in order to prevent any short
circuit on the antenna see Figure 11.
Figure 11. Active antenna current sense

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UM2231 Reference schematic and BOM
24
7 Reference schematic and BOM
7.1 Schematic
Figure 12. General schematic

Reference schematic and BOM UM2231
18/26 UM2231 Rev 4
7.1.1 Bill of material
Table 1. Bill of material
Refs Value Description Manufacturing 1 Manufacturing 2
Name Part number Name Part number
C1 4u7
Surface mount 0603
capacitor ceramic 4.7 µF,
10% 10V X7S 4µ7; 10;
X7S
Murata GRM188C71A475KE11
C2 22 uF
Capacitor, Ceramic,
SMD, MLCC,
Temperature Stable,
Class II, 22 µF, +/-20%,
6.3 V, X5R, 0805
KEMET C0805C226M9PACTU
C3 1nF
Automotive Grade
Surface mount 0402
capacitor ceramic 1nF,
10% 50V X7R 1nF; 50;
X7R
Murata GCM155R71H102KA37 TDK CGA2B2X7R1
H102K050BA
C7 10 nF
Multilayer Ceramic
Capacitors MLCC -
SMD/SMT SOFT 0402
50V 0.01uF X7R 10% T:
0.5 mm
TDK CGA2B3X7R1H103K050B
EMurata GCM155R71 H103JA55D
C4, C5 120 pF
Automotive Grade
Surface mount 0402
capacitor ceramic 120 pF,
5% 50 V C0G 120 pF; 50;
C0G
Murata GCM1555C1H121JA16 TDK CGA2B2C0G
1H121J050BA
L1 10 µH
Surface mount
magnetically shielded,
wire wound inductor for
power line applications.
10u ;1.4 A
TDK LTF5022T-100M1R4-LC
L2 5n6H
Surface mount wire
wound inductor. 5n6H;
3%; 0.76 A
Coilcraft 0402CS-5N6XJLU Murata LQW15AN5N
6G80D+00-21
L3 27nH
Unshielded Multilayer
Inductor, 27nH, 350mA,
460 mOhm Max, 0402
(1005 Metric)
Murata LQG15HS27NJ02 TDK MLG1005S27
NJT000
C6,C8,
C9,C10,
C11
NM
56pF surface mount,
general purpose
multilayer ceramic chip
capacitor, COG, 0201,
50V, +/-2%
Murata GRM0335C1H560GA01 TDK CGA1A2C0G
1H560J030BA
R1 1M Surface mount chip
resistor 1M; 5%; 1/16W Yageo RC0402JR-071ML

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UM2231 Layout recommendation
24
8 Layout recommendation
To guarantee good RF performance, 0402 components are preferable because they avoid
having too big component pads compared with RF 50 ohms line.
Place parallel components pads on 50 ohms line as in Figure 13.
Figure 13. Placing parallel component pads on 50 ohms line
For 50 ohms line bypassing it’s suggested to superimpose the pad of one component on the
pad of the other one as in Figure 14.
R2 68K Surface mount chip
resistor 68K; 1%; 1/16W Yageo AC0402FR-0768KL
R3 15K Surface mount chip
resistor 65K; 1%; 1/16W Yageo RC0402FR-1315KL
R4 10K Surface mount chip
resistor 10K; 5%; 1/16W Yageo RC0402JR-0710KP
U1 ST1S12G
R
Synchronous rectification
adjustable step-down
switching regulator
ST1S12GR; 0.7; 1.7
ST ST1S12GR TSOT23-5L
U2 BGA725L6
Low Noise Amplifier for
GPS, GLONASS, Galileo
and Compass BGA725L6
Infineon BGA725L6
Z1 B4327
Automotive SAW RF filter
for
GPS+COMPASS+GLON
ASS
Epcos B39162B4327P810
U3 LIV3F TESEOIII module SMPS
version ST LIV3F
Table 1. Bill of material (continued)
Refs Value Description Manufacturing 1 Manufacturing 2
Name Part number Name Part number

Layout recommendation UM2231
20/26 UM2231 Rev 4
Figure 14. Reuse pads of one component on the line bypassing
Place ground vias below Teseo-LIV3F all around and in the middle and also around the 3
ground pins.
The following layout presents layout recommendation to ensure the best performances of
Teseo-LIV3F. ST heartily recommends having a maximum of ground vias below the module
as illustrated in the Figure 15. In case of difficulties for all these vias, ensure to have several
vias at least around the 3 ground pins (pin1, pin10 and pin 12).
Figure 15. Layout proposal
It is important to have 50 ohms RF traces width as close as possible to components pads
size to avoid too much impedance jumps.
When possible, avoid any trace below Teseo-LIV3F module.