BK3431Q Datasheet

Last Updated on : 2024-06-24 06:04:50download

The BK3431Q chip is a highly integrated Bluetooth 4.2 low energy single mode device, with 2 Mbps data rate options. It integrates a high-performance RF transceiver, baseband, ARM9E core, rich feature peripheral units, programmable protocol, and profile to support Bluetooth LE application. The Flash program memory makes it suitable for customized applications.

General description

The BK3431Q is designed with an advanced technical process and integrated with switch DCDC regulator, that it has ultra-low power consumption and ultra-low leakage power. The embedded high-order interference suppression filter and fast automatic gain control logic make it work well in a high interference environment.

Block diagram

BK3431Q Datasheet


Bluetooth® SIG Bluetooth Low Energy Single-Mode (Bluetooth LE) compliant

  • Low-power 2.4GHz Transceiver
  • ARM968E Core Microprocessor integrated
  • 500 KB programmable Flash for Program and 64 KB RAM for Data
  • Operation voltage from 1.8 V to 3.6 V
  • Clock
    • 16 MHz crystal reference clock
    • 64 MHz digital PLL clock
    • 32 kHz ring oscillator
    • External 32KHz crystal oscillator
    • MCU can run with any clock source with internal frequency divider
  • Interface and peripheral units
    • Quad IO FLASH programming
    • JTAG, I2C, SPI interface
    • Two UART interface
    • Multi-channels PWM output
    • On-chip high accurate temperature sensor
    • On-chip 10 bit general ADC
    • GPIO with multiplexed interface functions
    • True random number generator
  • Typical Package Type: 32-pin QFN 4x4

Pin information

BK3431Q Datasheet

BK3431Q Datasheet

BK3431Q Datasheet

BK3431Q Datasheet

BK3431Q Datasheet

Functional description


The BK3431Q has many GPIO pins, which can be configured as either input or output. There are secondary functions available for GPIO pins and configurable by firmware.

At the beginning of the chip starts up, the chip will enter programming mode, JTAG mode, or normal according to the received command from Mode Selecting Pin.

BK3431Q Datasheet

Each GPIO pin can be the source to wake up MCU from shut downstate. In the shutdown state, any voltage level change on the pre-configured GPIO pin will trigger the wake-up procedure.


  • 16bits timers

    There are six 16 bits PWM timers. The clock of PWM timers can be selected as 32 kHz clock or 16 MHz clocks by the register.

    There are two modes of PWM timers. One is timer mode and another is PWM mode. The timer mode can generate interrupt to MCU. The PWM mode can generate PWM waveform and output to GPIO pins to drive external devices such as LEDs. Four GPIO pins can be used to output the PWM waveform separately.

  • 22bits timers

    There are four 22 bits timers, who run with a 16 MHz clock.

  • Watchdog timer and RTC timer

    The watchdog timer and RTC timer run on the always-on power domain, whose clock source is 32 kHz clock.

    The 16 bits watchdog timer runs with a 4 kHz frequency that its period can be up to 16 seconds. After the watchdog timer is expired, it will reset the whole chip.

    The 32 bits RTC timer in the always-on power domain run with ROSC frequency that its period can be up to one day. After the RTC timer is expired, it will wake up the MCU.


A 10-bit generic ADC is integrated into BK3431Q. A total of three external channels and two internal channels can be selected for ADC transfer. It supports both single and continuous modes.

BK3431Q Datasheet

UART, I2C, and SPI

There are two set UARTs, one set I2C, and one set SPI interface, which supports both master and slave mode.

The UART baud rate can be up to 3.2 MHz, and the SPI clock speed can be up to 4 MHz。

True random number generator

By using device noise variation characteristic, it provides a one-bit true random number generator.

Electrical specifications

BK3431Q Datasheet

BK3431Q Datasheet

Package information

The BK3431Q 32-Pin uses the 4mmx4mm QFN package.

BK3431Q Datasheet

Order information

BK3431Q Datasheet