BK3432 Module Datasheet

Last Updated on : 2024-06-14 03:09:04download

Product overview

With the data rate of 2 Mbit/s, the BK3432 chip is a highly integrated Bluetooth 5.0 dual-mode data SoC. It’s integrated with a high-performance RF transceiver, baseband, MCU, rich feature peripherals, and the programmable protocol and profile, to support Bluetooth classic and low energy applications. The flash memory enables BK3432 to work for customized applications.

The BK3432 is designed with the advanced technological process and integrated with a switch DCDC regulator so that it has ultra-low power consumption and ultra-low leakage power. Embedded with the high order interference suppression filter and fast automatic gain control logic, the BK3432 can work well in the environment of high interference.

The following figure shows the BK3432 block chip:

BK3432 Module Datasheet


  • Bluetooth® SIG Bluetooth dual-mode 5.0 compliant
  • Low-power 2.4GHz Transceiver
  • MCU integrated
  • 160 KB programmable flash for programs and 20 KB RAM for data
  • Program code read protection
  • The voltage is from 0.9 V to 3.6 V
  • Clock:
    • 16 MHz crystal reference clock
    • 64 MHz digital PLL clock
    • 32 kHz ring oscillator
    • External 32 kHz crystal oscillator
    • MCU can run with any clock source with internal frequency divider
  • Interface and peripheral units:
    • JTAG, I2C, and SPI interfaces
    • Two UARTs
    • Multi-channel PWM output
    • On-chip 10-bit general ADC
    • GPIO with multiplexed interface functions
    • True random number generator
  • Package type:
    • 32-pin QFN 4x4

Pin information


The following figure shows pins of the BK3432 QFN32.

BK3432 Module Datasheet

The following table gives detailed information about pins of the BK3432 QFN32.

Serial number Pin name Function Description
1 P05 Digital I/O General purpose I/O
2 P04 Digital I/O General purpose I/O
3 P03 Digital I/O General purpose I/O
4 P02 Digital I/O General purpose I/O
5 P01 Digital I/O General purpose I/O
6 P00 Digital I/O General purpose I/O
7 VCCRF Power RF power, 1.5 V
8 ANT RF RF signal port
9 VCCXTAL Power Crystal power, 1.5 V
10 XTALO Analog 16 MHz crystal output
11 XTALI Analog 16 MHz crystal input
12 P31 Digital I/O General purpose I/O
13 P32 Digital I/O General purpose I/O
14 P35 Digital I/O General purpose I/O
15 P14 Digital I/O General purpose I/O
16 RSTN Analog Active low, reset pin
17 XTAL32K Analog 32 kHz Crystal input
18 VDD12 Analog LDO output, 1.5 V
19 P17 Digital I/O General purpose I/O
20 P16 Digital I/O General purpose I/O
21 P34 Digital I/O General purpose I/O
22 VCCMCU Power Power, 1.5
23 VCCBAT Analog Power, 3 V
24 SW Analog Switch regulator pin in the two battery mode
25 VSSBAT Analog Ground
26 P33 Digital I/O General purpose I/O
27 P13 Digital I/O General purpose I/O
28 P12 Digital I/O General purpose I/O
29 P11 Digital I/O General purpose I/O
30 P10 Digital I/O General purpose I/O
31 P07 Digital I/O General purpose I/O
32 P06 Digital I/O General purpose I/O

Functional description


The BK3432 QFN32 has 20 GPIO pins in total. The pins can be configured to be input or output. There are secondary functions available to GPIO pins and configurable by firmware.

At the startup, which mode (programming mode, JTAG mode or normal mode) the chip enters depends on the received command from the mode selecting pin.

The following table describes the functional mapping of GPIO of BK3432.

Pin number Description I/O type Program mode Mode selection pin JTAG mode
P10 PWM[0] (20mA) O
P11 PWM[1] (20mA) O
P12 PWM[2] O
P13 PWM[3] O
P14 PWM[4]
P31 Ch1 I
P32 Ch2 I
P33 Ch3
P34 Ch4 I
P35 Ch5 I

Note: Each GPIO pin can wake up an MCU in the shutdown state. In the shutdown state, any change in voltage and level of the pre-configured GPIO pin will trigger the wake-up procedure.


  • PWM timers

    There are six 16-bit PWM timers. The clock of PWM timers can be 32 KHz or 16 MHz.

    There are two modes for a PWM timer: timer mode and PWM mode. In the timer mode, MCU can be interrupted. In the PWM mode, PWM waveforms can be generated and output to GPIO pins to drive external devices such as LED. Six GPIO pins can be used to output PWM waveforms separately.

  • Dog watching timer and RTC timer

    The dog watching timer and RTC timer run in the always-on-power domain, whose clock rate is 32 kHz.

    The 16-bit dog watching timer runs in the frequency of 4 kHz. Its period can be up to 16 second. After the dog watching timer expires, it will reset the whole chip.

    The 32-bit RTC timer in the always-on-power domain runs in the ROSC frequency. Its period can be up to one day. After an RTC timer expires, it will wake up the MCU.


A 10-bit generic ADC is integrated into BK3432. There are 5 external channels and 1 internal channel selected for transferring of an ADC. The ADC supports both single and continuous modes.

ADC channel number ADC source
Channel 1 GPIO 31
Channel 2 GPIO 32
Channel 3 GPIO 33
Channel 4 GPIO 34
Channel 5 GPIO 35
Channel 7 VCCBAT-pin

UART, I2C, and SPI

There are two sets of UARTs, and one set is I2Cs and the other set are SPI interfaces. All of them support both master and slave modes.

The UART baud rate can be up to 3.2 MHz and the SPI clock rate can be up to 4 MHz.


A generator produces a random number to make the system get better security communication.

Content of the flash will be protected (not readable, but erasable) as long as the LSB Bit 3 or 5 of the last 32-bit word of the last address 0x9FFF is set to 0.

Electrical specifications

The following table describes RF characteristics of BK3432:

Name Parameter (Condition) Minimum value Typical value Maximum value Unit Comment
VCC Voltage 0.9 3.0 3.6 V
TEMP Temperature -40 +27 +125 ºC
VIH High level VCC-0.3 VCC+0.3 V
VIL Low level VSS VSS+0.3 V
VOH High level (IOH=-0.25mA) VCC- 0.3 VCC V
VOL Low level(IOL=0.25mA) VSS VSS+0.3 V
IVDD Deep sleep 0.5 uA
IVDD Sleep current (RF OFF,32kHz clock,DIG Retention 1.8 uA
IVDD Active RX (3.3 V) 5.1 mA With DCDC regulator
IVDD Active TX @ -1 dBm (3.3V) 4.8 mA With DCDC regulator
FOP Operating frequency 2400 2480 MHz
FXTAL Crystal frequency 16 MHz
RFSK Air data rate 1 2 Mbps
PRF Output power -20 -1 +4 dBm
PBW Modulation 20 dB bandwidth 1 MHz
PRF1 Out of band emission 2 MHz -20 dB
PRF2 Out of band emission 3 MHz -58 dB
Dev Transmit FM deviation 115 250 300 kHz
Drift Transmit drift in any position 400 Hz/us
Max Input 1 E-3 BER -10 dBm
RXSENS 1 E-3 BER sensitivity -96 -97 dBm
Intermo dulation Pin=-64 dBm; Punwant=- 50 dBm; f0=2f1-f2, f2- f1=3, 4 or 5MHz -25 -22 dBm
C/ICO Co-channel C/I 7 dB
C/I1ST ACS C/I 1MHz -9 -6 dB
C/I2ND ACS C/I 2MHz -44 dB
C/I3RD ACS C/I 3MHz -50 dB
C/I1STI ACS C/I Image channel -25 dB
C/I2NDI ACS C/I 1 MHz -35 dB
Block Block @ 2399 and 2484 -15 dBm
Block Block @ 2 GHz and 3 GHz -15 dBm
Leakage Leakage @ < 1GHz -71 dBm
Leakage Leakage @ >1GHz -56 dBm

Package information

The BK3432 uses the QFN package of 4 mmx4 mm.

BK3432 Module Datasheet

Order information

Part number Package Shipping packing method Minimum order quantity
BK3432QN32C QFN 4mmx4mm 32-Pin Tape Reel 3000

Revision history

Version Date Description
0.1 Mar 12, 2017 This is the first release.
0.2 Nov 11, 2018 Modified the order information.