UM-B-077
DA14681 Wearable Development Kit Hardware Manual
User Manual
Revision 1.2
06-Apr-2017
CFR0012
6 of 47
© 2017 Dialog Semiconductor
2
System Overview
2.1
Features
■
Highly integrated Dialog Semiconductor DA14681 Bluetooth
® Smart SoC
■
Stand-alone module
■
High capacity slim size 190 mAh rechargeable LiPo battery
■
Low power 80
A (sleep current)
■
Low cost PCB touch pads
■
Incorporated heart rate monitor
■
Environmental sensor for temperature, humidity and air pressure readings
■
Combined Gyro/Accelerometer sensor unit
■
NFC module for payment applications
■
Access to processor via JTAG and UART from the enclosure
■
Compact design
■
35 mm x 39 mm x 9 mm PCBA
2.2
Electrical Characteristics
Table 1: DA14681 Wearable Reference Design
Parameter
Description
Conditions
Min
Typ
Max
Unit
V
BAT
battery supply voltage
3.6
3.8
4.2
V
I
SLEEP_TOTAL
average sleep current
conducted; T
A
= 25
°C
18
A
I
CONNECTED
average current when
connected to a host
conducted; T
A
= 25 °C
550
A
f
OPER
operating frequency
2400
2483.5
MHz
P
O
RF output power
conducted;
V
BAT
= 3 V;
T
A
= 25 °C
0
dBm
3
Introduction
Wearable devices are miniature electronic devices worn on the body, often integrated with or
designed to replace an existed accessory, such as a watch. This market segment is currently
booming and is enabled by Internet of Things (IoT) technology. Thus the need for smaller, low power
devices is rapidly increasing. Some of the current trends are smart watches, smart glasses, and
sports and fitness activity tracker equipment. In addition to the consumer market, the medical
industry is creating a demand for such devices that monitor physical conditions and functions.
The DA14681 wearable reference design described in this manual, is a low power and compact
prototype that can easily fit in a suitable enclosure to form a wearable smart watch. The PCB layout
of the wearable reference design is shown in
Figure 2
(top view) and Figure 3 (bottom view).
Each subblock of the system is described in sufficient detail to quickly start using it and test the
functionality. Section
7
presents the actual power measurements taken and describes the wrist watch
type enclosure.
The top level block diagram of the reference design is illustrated in
Figure 1.
