UM-B-077
DA14681 Wearable Development Kit Hardware Manual
User Manual
Revision 1.2
06-Apr-2017
CFR0012
9 of 47
© 2017 Dialog Semiconductor
4
DA14681 Reference Design - Motherboard
4.1
DA14681 System
The DA14681 is a flexible Bluetooth
®
low energy System-on-Chip combining an application
processor, memories, cryptography engine, power management unit, digital and analog peripherals
and a radio transceiver.
The DA14681 is based on an ARM
®
Cortex
®
-M0 CPU delivering up to 84 DMIPS and provides a
flexible memory architecture, enabling code execution from embedded memory (RAM, ROM) or non-
volatile memory (OTP or external Quad-SPI Flash memory for DA14681). The advanced power
management unit of the DA14681 enables it to run from primary and secondary batteries, as well as
provide power to external devices.
An on-chip PLL enables on-the-fly tuning of the system clock between 32 kHz and 96 MHz to meet
the high processing requirements.
Figure 4: DA14681 System Schematic
The DA14681 SoC power management subsystem consists of:
VBUS:
Battery charger input as well as USB bus voltage. A decoupling capacitor equal or less than
4.7
F is placed close to VBUS pin.
VBAT1:
Battery connection. A 1
F decoupling capacitor (C10), is required close to the pin (0402
package, 6.3 V). Voltage range for VBAT1 is 1.7 V to 4.75 V.
VBAT2:
Input of the SIMO DC-DC converter. It is shorted externally with VBAT1. A 1
F decoupling
capacitor (C11) is required next to the pin (0402 package, 6.3 V).
