Dialog Semiconductor DA14695 USB Kit User manual

User Manual
DA14695 USB Kit
UM-B-103
Abstract
This document outlines the system design, configuration options, and supported features of
DA14695 USB Kit, rev-C (331-22-C).

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
2 of 34
© 2019 Dialog Semiconductor
Contents
Abstract................................................................................................................................................ 1
Contents............................................................................................................................................... 2
Figures.................................................................................................................................................. 3
Tables ................................................................................................................................................... 3
1 Terms and Definitions................................................................................................................... 4
2 References..................................................................................................................................... 4
3 Introduction.................................................................................................................................... 5
4 System Overview........................................................................................................................... 5
4.1 Features................................................................................................................................ 5
4.2 System and Components Description (Top View)................................................................ 6
4.3 System and Components Description (Bottom View)........................................................... 7
4.4 Test Points............................................................................................................................ 8
4.5 Block Diagram..................................................................................................................... 10
5 USB Kit System ........................................................................................................................... 11
5.1 Overview............................................................................................................................. 11
5.2 DA14695 SoC System........................................................................................................ 11
5.3 DA14695 Pin Assignment................................................................................................... 14
5.4 Booting from UART............................................................................................................. 16
5.5 Crystals ............................................................................................................................... 16
5.6 Antenna and RF Port .......................................................................................................... 17
5.6.1 RF Measurements and Antenna Matching.......................................................... 17
5.7 QSPI Data Flash Memory (U5)........................................................................................... 18
5.8 Reset Circuit........................................................................................................................ 19
5.9 General Purpose Push Button............................................................................................ 19
5.10 Debugging Port DIP Switch ................................................................................................ 20
5.11 User Controlled LED........................................................................................................... 21
5.12 MikroBUS™ Modules.......................................................................................................... 21
5.13 GND Test Point................................................................................................................... 23
5.14 Over Voltage Protection Circuit (OVP)................................................................................ 23
5.15 Over-Current Protection Circuit on V30 power rail ............................................................. 24
5.16 USB HUB............................................................................................................................ 24
5.17 Debugging Processor (U4) ................................................................................................. 25
5.18 Power Section..................................................................................................................... 26
5.19 Power Selection Headers ................................................................................................... 27
6 PCB Layout.................................................................................................................................. 28
Appendix A Schematics.................................................................................................................... 29
Appendix B Bill of Materials............................................................................................................. 32
Revision History................................................................................................................................ 33

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
3 of 34
© 2019 Dialog Semiconductor
Figures
Figure 1: DA14695 USB Kit................................................................................................................... 5
Figure 2: DA14695 USB Kit - Top Side................................................................................................. 6
Figure 3: DA14695 USB Kit - Bottom Side............................................................................................ 7
Figure 4: Test Points Topology (BOTTOM View).................................................................................. 9
Figure 5: Block Diagram of DA14695 USB Kit.................................................................................... 10
Figure 6: DA14695 Schematic ............................................................................................................ 12
Figure 7: RF Matching Circuit, Printed Antenna, and SMA Connector............................................... 17
Figure 8: RF Port, RF Connector, RF Matching, and SMD Chip Antenna.......................................... 17
Figure 9: QSPI Data Flash .................................................................................................................. 18
Figure 10: Available packages for QSPI Data Flash........................................................................... 18
Figure 11: Reset Circuit....................................................................................................................... 19
Figure 12: RESET Push Button (K2)................................................................................................... 19
Figure 13: General Purpose Push Button ........................................................................................... 19
Figure 14: General Purpose Push Button K1 (Populated at TOP)...................................................... 20
Figure 15: Debugging DIP Switch....................................................................................................... 20
Figure 16: Debugging DIP switch........................................................................................................ 20
Figure 17: General Purpose Red LED ................................................................................................ 21
Figure 18: General Purpose Red LED D7........................................................................................... 21
Figure 19: Mikrobus™ Pin Assignment ............................................................................................... 21
Figure 20: J15, J16, J17, and J18 Female Sockets (Must Be Soldered by Users)............................. 22
Figure 21: Guides for Proper Mikrobus™ Click Boards Insertion ....................................................... 22
Figure 22: Mikrobus™ Pin Assignment............................................................................................... 22
Figure 23: GND Support Point ............................................................................................................ 23
Figure 24: GND Support Point (Must Be Placed by Users) ................................................................ 23
Figure 25: Over Voltage Protection Circuit.......................................................................................... 23
Figure 26: Over Current Protection Circuit on V30 Power Rail........................................................... 24
Figure 27: USB HUB Circuitry............................................................................................................. 24
Figure 28: Debugging Processor UART And JTAG Interface (U4)..................................................... 25
Figure 29: DA14695 USB Kit Power Tree........................................................................................... 26
Figure 30: Linear Voltage Regulators (LDOs) U2 And U3.................................................................. 26
Figure 31: PCB Cross Section ............................................................................................................ 28
Figure 32: DA14695 SoC Section....................................................................................................... 29
Figure 33: UART & JTAG Interface Chip Section............................................................................... 30
Figure 34: USB Hub Section ............................................................................................................... 31
Figure 35: Bill of Materials (BOM)....................................................................................................... 32
Tables
Table 1: Test Points Assignment........................................................................................................... 8
Table 2: USB Kit Pin Assignment........................................................................................................ 14
Table 3: Y1 (32 MHz crystal) characteristics....................................................................................... 16
Table 4: Y2 (32.768 kHz crystal) characteristics................................................................................. 16
Table 5: RF Components Names and Values..................................................................................... 17
Table 6: DA14695 power configurations............................................................................................. 27

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
4 of 34
© 2019 Dialog Semiconductor
1 Terms and Definitions
CIB Communication Interface Board
DCR Direct Current Resistor
DMIPS Dhrystone Million Instructions per Second
GPIO General Purpose Input Output
I2C Inter-Integrated Circuit
JTAG Join Test Action Group
LDO Low Dropout
MISO Master In Slave Out
MOSI Master Out Slave In
OTP One Time Programmable
OVP Over Voltage Protection
PC Personal Computer
PLL Phase-Locked Loop
QSPI Quad Serial Peripheral Interface
RF Radio Frequency
RFIO Radio Frequency Input Output
SDK Software Development Kit
SIMO Single-Inductor Multiple-Output
SMA Sub-Miniature version A
SMD Surface-Mount Device
SOC System on Chip
SOIC Small Outline Integrated Circuit
SPI Serial Peripheral Interface
SW Software
UART Universal Asynchronous Receiver-Transmitter
USB Universal Serial Bus
2 References
[1] DA1469x, Datasheet, Dialog Semiconductor.
[2] AN-B-052, DA1458x/68x Development kit J-Link Interface, Application Note, Dialog
Semiconductor.

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
5 of 34
© 2019 Dialog Semiconductor
3 Introduction
This document describes the DA14695 USB Kit. This kit offers a low-cost development board with
basic functionality. The development kit is implemented on a single PCB. The block diagram, the
actual board, the various sections and settings as well as the connectivity are presented. The
purpose of this cost-effective USB kit is to provide users with the capability of:
●Software development
●Programming DA14695 via JTAG or UART using Dialog's SDK
●Connecting MikroBUS™ modules
Figure 1: DA14695 USB Kit
4 System Overview
4.1 Features
The features of DA14695 USB kit include:
■Highly integrated DA14695 Bluetooth® Smart SoC from Dialog Semiconductor
■Access on GPIOs provided from the chip, when no MikroBUS™ is plugged in
■The ability to be connected directly to PC USB without extra cables
■Reset push button
■General purpose LED and button
■Using USB (5 V), LDO (3.3 V), or external battery as power source
■JTAG and UART interface over USB via SEGGER
■32 Mbit QSPI flash on board
■2.4 GHz printed antenna and slot for SMA connector
■32 MHz main crystal and 32.768 kHz low-power crystal
■Low cost
■Compact design
■A dimension of 100 mm × 26.5 mm × 11 mm

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
6 of 34
© 2019 Dialog Semiconductor
4.2 System and Components Description (Top View)
Figure 2: DA14695 USB Kit - Top Side
The USB kit is based on the DA14695 SoC in an VFBGA86 package. The marked and numbered
sections of the system are:
1. Type-A USB connector (J1)
2. GND support point (not populated)
3. LDO 3.3V (U2)
4. LDO 3.3V (U3)
5. MikroBUS™ slot #2 connection points (Right side - J18, 8 pins)
6. MikroBUS™ slot #2 diagnostical notch (serves as a guideline for add-on board insertion. For
more information, please check MikroBUS™ standard specifications)
7. Reset push button (K2)
8. DA14695 power selection headers (VBUS - J2, VBAT- J3) and battery connector header(J5)
9. MikroBUS™ slot #1 connection points (Right side - J16, 8 pins)
10. MikroBUS™ slot #1 diagnostical notch (serves as a guideline for add-on board insertion. For
more information, please check MikroBUS™ standard specifications)
11. 32 Mbit QSPI Flash (U5)
12. Debugging Connector (J7, CIB can be connected for UART interface access)
13. Red LED (D7)
14. SMA connector (optional - J6)
15. Printed antenna (ANT1)
16. DA14695 Bluetooth® Smart SoC
17. MikroBUS™ slot #1 connection points (Left side - J15, 8 pins)
18. JTAG & UART Switch selection (S1)
19. General purpose push button (K1)
20. MikroBUS™ slot #2 connection points (Left side - J17, 8 pins)
21. UART & JTAG interface (U4)

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
7 of 34
© 2019 Dialog Semiconductor
22. Green LED (D8)
23. USB HUB (U6)
24. OVP Circuit
4.3 System and Components Description (Bottom View)
Figure 3: DA14695 USB Kit - Bottom Side
The bottom side of DA14695 USB kit provides information about the MikroBUS™ pins assignment,
the SEGGER ID, and the date code. Test points have been placed for monitoring various signal
behaviors and voltage levels of the components. The marked and numbered sections of the system
are:
23. ID of UART & JTAG interface (U4)
24. MikroBUS™ slot #1 pins assignment
25. Test points (more details in Table 1)
26. GPIO connection header (not populated)
27. QSPI RAM I/O (1.8 V only, not populated)
28. MikroBUS™ slot #2 pins assignment

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
8 of 34
© 2019 Dialog Semiconductor
4.4 Test Points
Test points have been placed on the bottom side of the board and allow users to have access to
signals and I/Os, or measure supplies voltage levels. Table 1 shows the assignment for each test
point and Figure 4 shows the topology of the test points.
Table 1: Test Points Assignment
Test Point
Assigned to
Comments
TP1
V18
QSPI data flash supply voltage
TP2
VLED
Voltage level for Red LED
TP3
VBUS
Voltage level for VBUS pin of DA14695
TP4
V30
Voltage level for V30 pin of DA14695
TP5
V18
Voltage level for V18 pin of DA14695
TP6
V18P
Voltage level for V18P pin of DA14695
TP7
V14
Voltage level for V14 pin of DA14695
TP8
V12
Voltage level for V12 pin of DA14695
TP9
VBAT3V
Voltage level for VBAT3V pin of DA14695
TP12
GND
Ground
TP13
GND
Ground
TP14
GND
Ground
TP15
VBUS_IN
USB input voltage level
TP16
ESD_WARNING_LABEL
ESD sensitive device - Not electrically connected
TP17
GND
Ground
TP18
HUB_RST
USB HUB reset pin
TP19
3V3D
LDO 3.3V (U3) output voltage level
TP20
P0_06
General Purpose push button (K1)
TP21
P0_12
MicroBus™ BRSTn
TP22
P0_13
P0_13
TP23
P0_16
P0_16
TP24
P0_22
XTAL32km/P0_22
TP25
P0_23
XTAL32kp/P0_23
TP28
VDD_CORE
Core voltage level of UART & JTAG interface (U4)
TP29
NRST
For programming U4 in production - Not used for
development
TP30
ERASE
For programming U4 in production - Not used for
development
TP31
TMS_SWDIO
For programming U4 in production - Not used for
development
TP32
TCK_SWCLK
For programming U4 in production - Not used for
development

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
9 of 34
© 2019 Dialog Semiconductor
Test Point
Assigned to
Comments
TP33
SWO/TDO
For programming U4 in production - Not used for
development
TP34
DBLED
Voltage level for Green LED
TP35
SWO/TDO
For programming U4 in production - Not used for
development
TP36
GND
Ground
TP37
VBUS_OUT
Voltage level for VBUS pin of DA14695, when jumper
placed to header J2 (pin 2-3)
TP38
3V3
USB_HUB power supply
TP39
VLDO
Voltage level for VBAT pin of DA14695, when jumper
placed to header J3 (pin 1-2)
TP40
UTX
UART
TP41
RTS
UART
TP42
CTS
UART
TP43
URX
UART
TP44
SWDIO
JTAG
TP45
SWCLK
JTAG
TP46
P0_14
USBDP_2
TP47
P0_15
USBDM_2
TP48
VBUS_IN
USB input voltage level
TP49
SWDIO
JTAG
TP50
SWCLK
JTAG
Figure 4: Test Points Topology (BOTTOM View)

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
10 of 34
© 2019 Dialog Semiconductor
4.5 Block Diagram
U5
QSPI
Flash
USB_DP/DM
USB_DP/DM_2 JTAG & UART
Switch selection
3V3D
VBUS
VBUS_OUT
5V
OVP
3.3V LDO (U3)
32MHz 32KHz
LED (D7) &
Push button (K1)
RSTn
T-Reset
T-Reset
SMA
Connector
MikroBus
#1
J1
Type-A USB
Connector
K2
3V3
U6
USB HUB
MikroBus
#2
3.3V LDO (U2) VBAT
U4
SEGGER
NTC
J2
J3
J5
S1
NTC
U1
DA14695
3V3
VLDO
BATT
USB_DP_1
USB_DM_1
Printed
ZOR type
Antenna
Figure 5: Block Diagram of DA14695 USB Kit
The power of Dialog’s DA14695 SoC on the USB kit can be supplied from three different sources
(Figure 5):
●Default configuration: 5 V provided to VBUS pin, when jumper placed to J2 header (pin 2-3)
●Alternative configuration: 3.3 V provided to VBAT pin, through LDO (U2), when jumper placed to
J3 (pin 1-2)
●Alternative configuration: 3.6 V to 4.3 V provided to VBAT pin, from external LiPo battery
(connected to J5 header), when jumper placed to J3 (pin 2-3)

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
11 of 34
© 2019 Dialog Semiconductor
5 USB Kit System
5.1 Overview
●Board name/number:
○DA14695 USB Kit/331-22-C
●SoC:
○DA14695 in a VFBGA86 package
●Flash memory:
○MX25U3235F (32 Mbit) QSPI Flash Memory, 8-pin SOIC (200 mil) package
○1.8 V (V18P to pin V18F) power supply (default)
●Clock inputs:
○32 MHz crystal
○32.768 KHz crystal
●Ports:
○USB port for debugging purposes and battery charging
●Interfaces:
○UART-JLink CDC UART Port (listed under Ports in Device Manager)
○JTAG-JLink Driver (listed under Universal Serial Bus Controllers in Device Manager)
●Connectivity-Expansion connectors:
○Two MikroBUS™ modules can be plugged to J15, J16 and J17, J18 sockets, respectively
(users must solder the sockets manually)
●Power source selection:
○5 V on VBUS pin (default)
○3.3 V on VBAT via LDO (optional)
○3.6 V to 4.3 V from external LiPo battery (optional)
5.2 DA14695 SoC System
The DA14695 is a flexible System-on-Chip (SoC) combining an application processor, an advanced
power management unit, memories, a flexible sensor node controller, a cryptography engine for
enhanced security, digital and analog peripherals, and a new configurable Bluetooth Low Energy
MAC engine with a radio transceiver capable of a 6 dBm output.
The application processor used by DA14695 SoC system is the latest ARM® Cortex® M33™ CPU
which offers up to 144 DMIPS and a RAM of 512 kBytes. This application processor has an 8-region
MPU and a single-precision FPU which enables code execution from embedded memory (RAM) or
external QSPI FLASH via a 16 kB 4-way associative cache controller and the capability of decryption
on-the-fly without extra wait states.
The advanced power management unit of the DA14695 enables it to run from primary and secondary
batteries and provide power to external devices through the SIMO DCDC or integrated LDOs. The
on-chip hardware charger allows the natively rechargeable batteries to be charged over USB.

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
12 of 34
© 2019 Dialog Semiconductor
Figure 6: DA14695 Schematic
The DA14695 SoC power management subsystem consists of:
●VBUS: battery charger input as well as USB bus voltage
○A decoupling capacitor (C2, 0402 package, 6.3 V) equal or less than 4.7 μF is placed close to
VBUS pin
●VBAT1: battery connection
○It is shorted externally with VBAT2. A 4.7 μF decoupling capacitor (C8, 0402 package, 6.3 V)
is required to be placed close to the pin
○Voltage range for VBAT1 is 1.7 V to 4.75 V
○On this development kit, VBAT1 and VBAT2 are connected
●VBAT2: input of the SIMO DC-DC converter
○It is shorted externally with VBAT1. A 4.7 μF decoupling capacitor (C12, 0402 package, 6.3V)
is required to be placed close to the pin
○On this development kit, VBAT1 and VBAT2 are connected
●V30: output voltage rail (3 V)
○A ceramic decoupling capacitor of 4.7 μF (C36, 0402 package, 10 V) is required to be placed
close to the pin
○V30 cannot be turned off

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
13 of 34
© 2019 Dialog Semiconductor
○V30 is the default option for GPIO voltage levels (expect for the QSPI-RAM I/Os which are
fixed to 1.8 V)
○The current delivery capability of the V30 power rail is 150 mA
○Overcurrent protection circuit limits the current on V30 if an external device misbehaves
●SIMO DC-DC converter outputs: V18, V18P, V12, and V14.
○The inductor needed for DC-DC operation is placed externally. A low DCR inductor (L1) of
470 nH (0805 package) is connected on LX/LY pins
○V18 and V18P: power rails (1.8 V) for supplying external devices, even when the system is in
sleep mode
–Decoupling ceramic capacitors (C4 and C5) of 22 μF (0603 package, 6.3 V), are placed as
close as possible to the V18 and V18P pins.
–V18 is assigned to peripherals devices, QSPI-RAM, and through register setting for GPIOs
–V18P is assigned to external QSPI Data Flash
–The current delivery capability of the V18 and V18P power rails is 50 mA in active mode
○V12: power rail that supplies the digital core of DA14695 and delivers up to 50 mA at 1.2 V in
active mode. It should not be used to supply external devices
–A 10 μF decoupling capacitor (C7, 0603 package, 6.3 V) is placed close to V12 pin
○V14: power rail that delivers up to 20 mA at 1.4 V and should not be used for supplying
external devices
–A 10 μF decoupling capacitor (C6, 0603 package, 6.3 V) is placed close to the V14 pin
●VSUP_RF: radio supply voltage
○It is connected to V14 externally. A 10 μF capacitor (C9, 0603 package, 6.3 V) is placed as
close to the VSUP_RF pin as possible.

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
14 of 34
© 2019 Dialog Semiconductor
5.3 DA14695 Pin Assignment
Most of the available signals are utilized or extracted on the breakout connectors.
Table 2 provides the pin assignment of the breakout connectors on the USB kit and the related pin
name on the VFBGA86 package of the DA14695.
Table 2: USB Kit Pin Assignment
AQFN60 Pin
Name
Development Kit Signal
Header
Pin
Comments
P0_00
P0_00
J8.3
GPIO
P0_01
P0_01
J8.4
GPIO
P0_02
P0_02
J8.5
GPIO
P0_03
P0_03
J8.6
GPIO
P0_04
P0_04
J8.7
GPIO
P0_05
P0_05
J8.8
GPIO
P0_06
P0_06
-
General Purpose push button (K1)
P0_07
CTS
-
UART interface
P0_08
URX
-
UART interface
P0_09
UTX
-
UART interface
P0_10
SWDIO
-
JTAG interface
P0_11
SWCLK
-
JTAG interface
P0_12
P0_12
J15.2/J17.2
MikroBUS™ BRSTn (slot 1,2)
P0_13
P0_13
-
GPIO
P0_14
USBDP_2
-
USB Data plus (+)
P0_15
USBDM_2
-
USB Data minus (-)
P0_16
P0_16
-
GPIO
P0_17
GPIO/MB2_TX
J18.4
GPIO/MikroBUS™ Universal Asynchronous
Transmitter (slot 2)
P0_18
GPIO/MB2_SCL
J18.5
GPIO/MikroBUS™ I2C SCL (slot 2)
P0_19
GPIO/MB2_SDA
J18.6
GPIO/MikroBUS™ I2C SDA (slot 2)
P0_20
GPIO/MB1_CS
J15.3
GPIO/MikroBUS™ CS (slot 1)
P0_21
GPIO/MB1_SCK
J15.4
GPIO/MikroBUS™ SCK (slot 1)
P0_22
XTAL32M
-
XTAL 32.768 kHz minus (-)
P0_23
XTAL32P
-
XTAL 32.768 kHz plus (+)
P0_24
GPIO/MB1_MISO
J15.5
GPIO/MikroBUS™ MISO (slot 1)
P0_25
GPIO/MB2_AN
J17.1
GPIO/MikroBUS™ Analog (slot 2)
P0_26
GPIO/MB1_MOSI
J15.6
GPIO/MikroBUS™ MOSI (slot 1)
P0_27
GPIO/MB1_INT
J16.2
GPIO/MikroBUS™ Interrupt (slot 1)
P0_28
GPIO/MB1_RX
J16.3
GPIO/MikroBUS™ Universal Asynchronous
Receiver (slot 1)

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
15 of 34
© 2019 Dialog Semiconductor
AQFN60 Pin
Name
Development Kit Signal
Header
Pin
Comments
P0_29
GPIO/MB1_TX
J16.4
GPIO/MikroBUS™ Universal Asynchronous
Transmitter (slot 1)
P0_30
GPIO/MB1_SCL
J16.5
GPIO/MikroBUS™ I2C SCL (slot 1)
P0_31
GPIO/MB1_SDA
J16.6
GPIO/MikroBUS™ I2C SDA (slot 1)
P1_00
RTS
J4.3
UART interface
P1_01
GPIO/MB_PWM/RED_LED
J16.2/J4.4
GPIO/MikroBUS™ I2C PWM (slot 1)/Red LED
P1_02
GPIO/MB2_CS
J17.3/J4.5
GPIO/MikroBUS™ CS (slot 2)
P1_03
GPIO/MB2_SCK
J17.4/J4.6
GPIO/MikroBUS™ SCK (slot 2)
P1_04
GPIO/MB2_MISO
J17.5/J4.7
GPIO/MikroBUS™ MISO (slot 2)
P1_05
GPIO/MB2_MOSI
J17.6/J4.8
GPIO/MikroBUS™ MOSI (slot 2)
P1_06
GPIO/MB2_PWM
J18.1
GPIO/MikroBUS™ PWM (slot 2)
P1_07
GPIO/MB2_INT
J18.2
GPIO/MikroBUS™ interrupt (slot 2)
P1_08
GPIO/MB2_RX
J18.3
GPIO/MikroBUS™ Universal Asynchronous
Receiver (slot 2)
P1_09
GPIO/MB1_AN
J15.1
GPIO/MikroBUS™ Analog (slot 1)
P1_10
-
-
Not connected
P1_11
-
-
Not connected

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
16 of 34
© 2019 Dialog Semiconductor
5.4 Booting from UART
There is only one boot loader option for booting from UART using pins P0_9 (T_TX) and P0_8
(T_RX). Please note that UART-booting does not support hardware handshake signals (RTS/CTS).
The settings for UART booting are:
●Baud rate 115.2 kbps
●8 bits
●No parity
●1 stop bit
For more details on booting with UART, check application note AN-B-052 ([2]).
5.5 Crystals
The DA14695 SoC has two Digitally Controlled Crystal Oscillators, one at 32 MHz (XTAL32M) and
the other at 32.768 kHz (XTAL32K). XTAL32K has no trimming capabilities and is used as the clock
of the Extended/Deep Sleep modes, while XTAL32M can be trimmed.
The crystals used on the USB kit are specified in Table 3 and Table 4.
Table 3: Y1 (32 MHz crystal) characteristics
Reference Designator
Value
Part Number
XRCGB32M000F1H00R0
Frequency
32 MHz
Accuracy
±10 ppm
Load Capacitance (CL)
6 pF
Equivalent Series Resistance (ESR)
60 Ω
Drive Level (PD)
150 μW
Table 4: Y2 (32.768 kHz crystal) characteristics
Reference Designator
Value
Part Number
ABS07-32.768KHZ-7-T
Frequency
32.768 kHz
Accuracy
±20 ppm
Load Capacitance (CL)
12.5 pF
Shunt Capacitance (C0)
0.9 - 1.2 pF
Equivalent Series Resistance (ESR)
100 Ω
Drive Level (PD)
0.1 μW

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
17 of 34
© 2019 Dialog Semiconductor
5.6 Antenna and RF Port
A printed type antenna is currently used as the default antenna in the DA14695 USB Kit. The
DA14695 USB Kit provides a single-ended RFIO port matched to 50 Ω. The RF port consists of the
RFIOp, RFIOm, and RFIOm2 pins, of which RFIOm and RFIOm2 are connected to ground. A copper
trace with an impedance of 50 Ω interconnects the RF port and the printed antenna (ANT1). A Pi-
network (Z1, Z2, and Z3) is added for antenna matching purposes.
Figure 7: RF Matching Circuit, Printed Antenna, and SMA Connector
The DA14695 USB Kit provides an RF connector (no populated) in parallel with the SMD chip
antenna. The RF connector can be used for conducted RF evaluation/testing. The RF connector type
is 142-0761-861. To perform RF measurements using the RF connector J6, users must remove the
capacitor Z5 (10 pF) and place the capacitor Z4 (10 pF).
Figure 8: RF Port, RF Connector, RF Matching, and SMD Chip Antenna
5.6.1 RF Measurements and Antenna Matching
RF measurements have been performed to increase the efficiency of the ANT1. The values of the RF
components are shown in Table 5.
Table 5: RF Components Names and Values
Component Name
Component Value
Manufacturer Part Number
Z1
1.6 nH
LQP15MN1N5W02D
Z2
2.4 pF
GJM1555C1H2R4BB01D
Z3
-
Not populated

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
18 of 34
© 2019 Dialog Semiconductor
5.7 QSPI Data Flash Memory (U5)
The DA14695 USB Kit includes an external QSPI Data Flash memory from Macronix. The
MX25U3235F Flash memory supports the standard Serial Peripheral Interface (SPI), Dual/Quad I/O
SPI as well as 2-clock instruction cycle Quad Peripheral Interface (QPI), Serial Clock, Chip Select,
Serial Data I/O0 (DI), I/O1(D0), I/O2 (/WP), and I/O3(/HOLD).
The selected QSPI flash for the DA14695 USB Kit is MX25U3235FM2I-10G in 8-pin SOIC 208mil
package (U5). DA14695 USB Kit can support QSPI Data flash with 8-pin SOIC 150mil package
(U5Y) or QSPI Data flash with 8-pin USON (2x3) package (U5X), as shown in Figure 10.
Figure 9: QSPI Data Flash
The DA14695 uses the external Flash memory for directly executing code with some help from the
internal cache, or simply for mirroring the contents in RAM during booting.
Figure 10: Available packages for QSPI Data Flash

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
19 of 34
© 2019 Dialog Semiconductor
5.8 Reset Circuit
Figure 11: Reset Circuit
The DA14695 comprises an RSTn pad which is active low. The DA14695 USB Kit can be reset by
pressing the on-board RESET push button (K2, Figure 12) or through software from the UART &
JTAG interface processor (U4, Figure 2, #21). The Reset push button drives the RSTn pad to the
ground.
Figure 12: RESET Push Button (K2)
5.9 General Purpose Push Button
Figure 13: General Purpose Push Button
General purpose push button K1 is connected to P0_06 (Figure 13). It is populated and placed on
the top side of the board (Figure 14).

UM-B-103
DA14695 USB Kit
User Manual
Revision 1.0
14-Feb-2019
CFR0012
20 of 34
© 2019 Dialog Semiconductor
Figure 14: General Purpose Push Button K1 (Populated at TOP)
5.10 Debugging Port DIP Switch
Figure 15: Debugging DIP Switch
S1 is a DIP switch which allows users to disconnect the pins used for debugging (default state is all
pins connected) to allow accurate deep sleep power measurement.
Figure 16: Debugging DIP switch