ST Teseo-LIV3F User Manual

February 2019 UM2231 Rev 6 1/26

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UM2231

User manual

Teseo-LIV3 GNSS Modules - Hardware Manual

Introduction

Teseo-LIV3 is a family of tiny GNSS modules 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.

This document is relevant for the following Teseo-LIV3 modules.

In Figure 1 pinout of the module is represented as follows:

Figure 1. Teseo-LIV3 pinout

Table 1. Teseo-LIV3 supported devices

Device type Description

Teseo-LIV3F Tiny GNSS module flash based

Teseo-LIV3R Tiny GNSS module ROM based

www.st.com

Contents UM2231

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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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

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) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

5 Standby modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5.1 Software standby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5.2 Hardware standby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

6 Front ends management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

6.1 External LNA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

6.2 Active antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

7 Reference schematic and BOM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

7.1 Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

7.1.1 Bill of material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

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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-LIV3 . . . . . . . . . . . . . . . . . . . . . 22

9.2 Chip antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

9.3 Remote antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

10 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

List of tables UM2231

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List of tables

Table 1. Teseo-LIV3 supported devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Table 2. Bill of material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 3. List of suggested antennas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Table 4. List of SMD antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Table 5. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

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UM2231 List of figures

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List of figures

Figure 1. Teseo-LIV3 pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 2. Inductor on VCC power line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3. Teseo-LIV3 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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 10. Active antenna current switch control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 11. Active antenna current sense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 12. General schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 13. Placing parallel component pads on 50 ohms line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 14. Reuse pads of one component on the line bypassing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 15. Layout proposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Figure 16. Pin1 gnd “isolation” example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Figure 17. Antenna vs Teseo-LIV3 placement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Figure 18. Antenna on bottom layer and Teseo-LIV3 on top layout example . . . . . . . . . . . . . . . . . . . 22

Figure 19. 25×25mm SMD Antenna and Teseo-LIV3 on same layer example . . . . . . . . . . . . . . . . . . 23

Figure 20. Chip Antenna and Teseo-LIV3 on same layer example . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Power UM2231

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1 Power

Teseo-LIV3 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-LIV3 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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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-LIV3 GNSS working.

Figure 3. Teseo-LIV3 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

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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-LIV3 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.

If all 3 pins have common supply, 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%.