Microchip Technology BM62, BM64 User Manual
Bluetooth® Stereo Audio Module
BM62/64
Features
• Qualified for Bluetooth v5.0 specification
• Supports A2DP 1.3, AVRCP 1.6, HFP 1.7.2, HSP
1.2 and SPP 1.2
• Supports Bluetooth 5.0 dual-mode (BDR/EDR/
BLE) specifications
• Stand-alone module with on-board PCB antenna
and Bluetooth stack
• Supports high resolution up to 24-bit, 96 kHz
audio data format
• Supports Bluetooth Low Energy data rate up to
1Mbits/s
• Supports connection of two hosts with HFP/A2DP
profiles simultaneously
• Transparent UART mode for seamless serial data
over UART interface
• Supports virtual UART communication between
host MCU and smartphone applications by Bluetooth SPP or BLE link
• Easy to configure with Windows
by external MCU
• Supports firmware field upgrade
• Supports one microphone
• Compact surface mount module:
- BM62: 29 x 15 x 2.5 mm
- BM64: 32 x 15 x 2.5 mm
• Castellated surface mount pads for easy and
reliable host PCB mounting
• RoHS compliant
• Ideal for portable battery-operated devices
• Internal battery regulator circuitry
®
GUI or directly
• Supports Serial Copy Management System
(SCMS-T) content protection
FIGURE 1: BM62 MODULE
FIGURE 2: BM64 MODULE
DSP Audio Processing
• Supports 64 kbps A-Law, -Law PCM format/
Continuous Variable Slope Delta (CVSD) modulation for SCO channel operation
• Supports 8/16 kHz noise suppression
• Supports 8/16 kHz echo cancellation
• Supports Modified Sub-Band Coding (MSBC)
decoder for wide band speech
• Built-in High Definition Clean Audio (HCA) algorithms for both narrow band and wide band
speech processing
• Packet loss concealment (PLC)
• Built-in audio effect algorithms to enhance audio
streaming
2021 Microchip Technology Inc. Advanced DS60001403G-Page 1
Audio Codec
• Sub-band Coding (SBC) and optional Advanced
Audio Coding (AAC) decoding
• 20-bit Digital-to-Analog Converter (DAC) with
98 dB SNR
• 16-bit Analog-to-Digital Converter (ADC) with
92 dB SNR
• Supports up to 24-bit, 96 kHz I
(BM64 only)
2
S digital audio
BM62/64
Peripherals
• Built-in lithium-ion and lithium-polymer battery
charger (up to 350 mA)
• Integrated 1.8V and 3V configurable switching
regulator and Low-Dropout (LDO) regulator
• Built-in ADC for battery monitoring and voltage
sense
• Built-in ADC for charger thermal protection
• Built-in Undervoltage Protection (UVP)
• An auxiliary input port for external audio input
• Two LED drivers
• Multiple I/O pins for control and status
RF/Analog
• Frequency spectrum: 2.402 GHz to 2.480 GHz
• Receive sensitivity: -90 dBm (2 Mbps EDR)
• Output Power
- BM64 Class 1: +15 dBm typical
- BM62/64 Class 2: +2 dBm typical
HCI Interface
• High-speed HCI-UART interface (supports up to
921,600 bps)
Description
The BM62/64 Stereo Audio module is a fully qualified
Bluetooth v5.0 dual-mode (BDR/EDR/BLE) module for
designers to add wireless audio and voice applications
to their products. The BM62/64 module is a Bluetooth
SIG-certified module that provides a complete wireless
solution with a Bluetooth stack, an integrated PCB
antenna, and worldwide radio certifications in a
compact surface-mount package.
The BM62/64 module has several SKUs. The BM62
module is a Class 2 device and the BM64 module is
available in both Class 1 and Class 2 versions.
MAC/Baseband Processor
• Supports Bluetooth 5.0 dual-mode
- BDR/EDR transport for audio, voice, and
SPP data exchange
- BLE transport for proprietary transparent
service and Apple Notification Center Service
(ANCS) data exchange
Operating Condition
• Operating voltage: 3.2V to 4.2V
• Operating temperature: -20°C to +70°C
Compliance
• Bluetooth Special Interest Group (SIG) QDID:
110148 (BM62, BM64 Class 2) and 110159
(BM64 Class 1)
• Certified to the United States (FCC), Innovation,
Science and Economic Development Canada
(ISED), European Economic Area (CE), Korea
(KCC), Taiwan (NCC), Japan (MIC), China
(SRRC), and Brazil (ANATEL) radio regulations
Applications
• Portable speaker
• Multiple speakers
• Headset
DS60001403G-Page 2 Advanced 2021 Microchip Technology Inc.
BM62/64
Table of Contents
1.0 Device Overview ....................................................................................................................................................... 6
2.0 Audio....................................................................................................................................................................... 15
3.0 Transceiver ............................................................................................................................................................. 20
4.0 Power Management Unit ........................................................................................................................................ 22
5.0 Application Information .......................................................................................................................................... 25
6.0 Printed Antenna Information .................................................................................................................................. 43
7.0 Physical Dimensions.............................................................................................................................................. 46
8.0 Electrical Characteristics........................................................................................................................................ 50
9.0 Soldering Recommendations ................................................................................................................................. 58
10.0 Ordering Information ............................................................................................................................................ 59
Appendix A: Certification Notices................................................................................................................................. 60
Appendix B: Revision History....................................................................................................................................... 70
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2021 Microchip Technology Inc. Advanced DS60001403G-Page 3
BM62/64
1.0 DEVICE OVERVIEW
The BM62 and BM64 Stereo Audio modules are built
around Microchip Technology IS2062 and IS2064
SoCs.
The IS2062/64 SoC integrates the Bluetooth 5.0 dualmode radio transceiver, Power Management Unit
(PMU), a crystal and DSP. Users can configure the
BM62/64 module by using the UI tool and DSP tool, a
Windows-based utility.
Note: The UI and DSP tools are available for
download from the Microchip website at:
www.microchip.com/BM62 and
www.microchip.com/BM64.
Figure 1-1 illustrates a typical example of the BM62
module, which is connected to an external audio
amplifier and the MCU.
FIGURE 1-1: SINGLE SPEAKER APPLICATION USING BM62 MODULE
Figure 1-2 illustrates a typical example of the Class 1
BM64 module, which is connected to an external MCU
and a DSP/codec.
FIGURE 1-2: SINGLE SPEAKER APPLICATION USING BM64 MODULE
DS60001403G-Page 4 Advanced 2021 Microchip Technology Inc.
Figure 1-3 illustrates the multi-speaker application
using the BM64 module.
FIGURE 1-3: MULTI-SPEAKER APPLICATION USING BM64 MODULE
BM62/64
2021 Microchip Technology Inc. Advanced DS60001403G-Page 5
BM62/64
Table 1-1 provides the key features of the BM62/64
module.
TABLE 1-1: BM62/64 KEY FEATURES
Feature BM62 CLASS 2 BM64 CLASS 2 BM64 CLASS 1
Application Headset/Speaker Multi-Speaker/Soundbar
Stereo/mono Stereo Stereo Stereo
Pin count 37 43 43
Dimensions (mm
PCB antenna Yes Yes Yes
Tx power (typical) 2 dBm 2 dBm 15 dBm
Audio DAC output 2-channel 2-channel 2-channel
DAC (single-ended) SNR at 2.8V (dB) -98 -98 -98
DAC (capless) SNR at 2.8V (dB) -98 -98 -98
ADC SNR at 2.8V (dB) -92 -92 -92
2
I
S digital output No Yes Yes
Analog Auxiliary-Input Yes Yes Yes
Mono microphone 1 1 1
External audio amplifier interface Yes Yes Yes
UART Yes Yes Yes
Full-speed USB 1.1 No Yes Yes
LED driver 2 2 2
Internal DC-DC step down regulator Yes Yes Yes
DC 5V adapter input Yes Yes Yes
Battery charger (350 mA max) Yes Yes Yes
ADC for thermal charger protection Yes Yes Yes
Under voltage protection (UVP) Yes Yes Yes
GPIO 10 12 12
Button support 6 6 6
EEPROM Yes Yes Yes
Customized voice prompt 8K Sampling Rate, Stored in EEPROM with approximately
Multitone Yes Yes Yes
DSP functions (audio playback and voice call) Yes Yes Yes
BLE Yes Yes Yes
Bluetooth profiles
A2DP 1.3 1.3 1.3
AVRCP 1.6 1.6 1.6
HFP 1.7.2 1.7.2 1.7.2
HSP 1.2 1.2 1.2
SPP 1.2 1.2 1.2
2
) 15 x 29 15 x 32 15 x 32
800 bytes/second
DS60001403G-Page 6 Advanced 2021 Microchip Technology Inc.
Figure 1-4 illustrates the pin diagram of the BM62
module.
FIGURE 1-4: BM62 MODULE PIN DIAGRAM
BM62/64
2021 Microchip Technology Inc. Advanced DS60001403G-Page 7
BM62/64
Table 1-2 provides the pin description of the BM62
module.
TABLE 1-2: BM62 MODULE PIN DESCRIPTION
Pin No Pin Type Pin Name Description
1 I/O P0_0 Configurable control or indication pin
(Internally pulled up, if configured as an input)
• Slide switch detector, active-high
• UART TX_IND, active-low (used by Bluetooth system to wakeup the host MCU)
2 I EAN External address bus negative
System configuration pin along with the P2_0 and
P2_4 pins, used to set the module in any one of the following three modes:
• Application mode (for normal operation)
• Test mode (to change EEPROM values)
• Write Flash mode (to load a new firmware into the
module), refer to Ta b le 5 -1
Flash type module already installed internal pull down
resistor 4.7 kOhm to GND
3 I/O P3_0 Configurable control or indication pin
(Internally pulled up, if configured as an input)
Auxiliary input detector, active-low
4 I/O P2_0 System configuration pin along with P2_4 and EAN
pins used to set the module in any one of the following
three modes:
• Application mode (for normal operation)
• Test mode (to change EEPROM values)
• Write Flash mode (to load a new firmware into the
module), refer to Ta b le 5 -1
5 I/O P1_5 Configurable control or indication pin
(Internally pulled up, if configured as an input)
• NFC detection pin, active-low
• Out_Ind_1
• Slide switch detector, active-high
6 I/O P0_4 Configurable control or indication pin
(Internally pulled up, if configured as an input)
• NFC detection pin, active-low
• Out_Ind_1
7 O SPKR Right-channel, analog headphone output
8 O AOHPM Headphone common mode output/sense input
9 O SPKL Left-channel, analog headphone output
10 P VDDA Analog reference voltage. Do not connect, for internal
use only
11 I MIC1_P MIC1 mono differential analog positive input
12 I MIC1_N MIC1 mono differential analog negative input
13 P MIC1_BIAS Electric microphone biasing voltage
14 I AIR Right-channel, single-ended analog input
15 I AIL Left-channel, single-ended analog input
Legend: I= Input pin O= Output pin I/O= Input/Output pin P= Power pin
Note: All I/O pins can be configured using the UI tool, a Windows utility.
DS60001403G-Page 8 Advanced 2021 Microchip Technology Inc.
BM62/64
TABLE 1-2: BM62 MODULE PIN DESCRIPTION (CONTINUED)
Pin No Pin Type Pin Name Description
16 I RST_N System Reset (active-low)
17 - NC No connection
18 I/O P0_1 Configurable control or indication pin
(Internally pulled up, if configured as an input)
• FWD key when Class 2 RF (default), active-low
• Class 1 Tx control signal for external RF Tx/Rx
switch, active-high
19 P VDD_IO I/O positive supply. Do not connect, for internal use
only
20 P ADAP_IN 5V power adapter input, used to charge the battery in
the Li-Ion battery power applications
21 P BAT_IN Power Supply input.
Voltage range: 3.2V to 4.2V. Source can either be a
Li-Ion battery or any other power rail on the host board
22 P AMB_DET Analog input for ambient temperature detection
23 P GND Ground reference
24 P SYS_PWR System power output derived from ADAP_IN or
BAT_IN. Refer to reference schematic for external connection.
25 P BK_OUT 1.8V buck regulator output. Do not connect to other
devices. For internal use only
26 I MFB • Multi-Function Button and power-on key
• UART RX_IND, active-high (used by host MCU to
wakeup the Bluetooth system)
27 O LED1 LED driver 1
28 O LED2 LED driver 2
29 I/O P2_4 System configuration pin along with P2_0 and EAN
pins used to set the module in any one of the following
three modes:
• Application mode (for normal operation)
• Test mode (to change EEPROM values)
• Write Flash mode (to load a new firmware into the
module), refer to Ta b le 5 -1
30 I/O P0_2 Configurable control or indication pin
(Internally pulled up, if configured as an input)
Play/Pause key (default), active-low
31 I/O P0_3
32 I/O HCI_TXD HCI UART data output
33 I/O HCI_RXD HCI UART data input
Legend: I= Input pin O= Output pin I/O= Input/Output pin P= Power pin
Note: All I/O pins can be configured using the UI tool, a Windows utility.
Configurable control or indication pin
(Internally pulled up, if configured as an input)
• REV key (default), active-low
• Buzzer signal output
• Out_Ind_2
• Class 1 Rx Control signal of external RF Tx/Rx
switch, active-high
2021 Microchip Technology Inc. Advanced DS60001403G-Page 9
BM62/64
TABLE 1-2: BM62 MODULE PIN DESCRIPTION (CONTINUED)
Pin No Pin Type Pin Name Description
34 I/O P0_5
35 I/O P2_7
36 - NC No connection
37 P GND Ground reference
38 - NC No connection
39 - NC No connection
40 - NC No connection
Legend: I= Input pin O= Output pin I/O= Input/Output pin P= Power pin
Note: All I/O pins can be configured using the UI tool, a Windows utility.
Configurable control or indication pin
(Internally pulled up, if configured as an input)
Volume-down key (default), active-low
Configurable control or indication pin
(Internally pulled up, if configured as an input)
Volume-up key (default), active-low
DS60001403G-Page 10 Advanced 2021 Microchip Technology Inc.
Figure 1-5 illustrates the pin diagram of the BM64
module.
FIGURE 1-5: BM64 MODULE PIN DIAGRAM
BM62/64
2021 Microchip Technology Inc. Advanced DS60001403G-Page 11
BM62/64
Table 1-3 provides the pin description of the BM64
Module.
TABLE 1-3: BM64 MODULE PIN DESCRIPTION
Pin No Pin Type Pin Name Description
2
1 I/O DR0 I
2I/ORFS0I
3I/OSCLK0I
4I/ODT0I
5 O AOHPR Right-channel, analog headphone output
6 O AOHPM Headphone common mode output/sense input
7 O AOHPL Left-channel, analog headphone output
8 I MIC_N1 MIC1 mono differential analog negative input
9 I MIC_P1 MIC1 mono differential analog positive input
10 P MIC_BIAS Electric microphone biasing voltage
11 I AIR Right-channel, single-ended analog input
12 I AIL Left-channel, single-ended analog input
13 I RST_N System Reset (active-low)
14 P GND Ground reference
15 I/O P1_2 EEPROM clock SCL
16 I/O P1_3 EEPROM data SDA
17 I/O P0_4
18 I/O P1_5
19 I HCI_RXD HCI-UART data input
20 O HCI_TXD HCI-UART data output
21 P VDD_IO I/O positive supply. Do not connect, for internal use only
22 P BAT_IN Power Supply input.
23 P ADAP_IN 5V power adapter input, used to charge the battery in the
24 P SYS_PWR System power output derived from ADAP_IN or BAT_IN.
25 P AMB_DET Analog input for ambient temperature detection
26 I MFB • Multi-Function Button and power-on key
27 O LED2 LED driver 2
28 O LED1 LED driver 1
Legend: I= Input pin O= Output pin I/O= Input/Output pin P= Power pin
Note: All I/O pins can be configured using the UI tool, a Windows utility.
S interface: digital left/right data
2
S interface: left/right clock
2
S interface: bit clock
2
S interface: digital left/right data
Configurable control or indication pin
(Internally pulled up, if configured as an input)
• NFC detection pin, active-low
• Out_Ind_1
Configurable control or indication pin
(Internally pulled up, if configured as an input)
• NFC detection pin, active-low
• Slide switch detector, active-high
• Out_Ind_1
• Multi-SPK Central/Peripheral mode control (firmware
dependent)
Voltage range: 3.2V to 4.2V. Source can either be a Li-Ion battery or any other power rail on the host board
Li-Ion battery power applications
Refer to reference schematic for external connection.
• UART RX_IND, active-high (used by host MCU to
wakeup the Bluetooth system)
DS60001403G-Page 12 Advanced 2021 Microchip Technology Inc.
BM62/64
TABLE 1-3: BM64 MODULE PIN DESCRIPTION (CONTINUED)
Pin No Pin Type Pin Name Description
29 I/O P3_7
30 I/O P3_5 Configurable control or indication pin
31 I/O P0_0
32 I EAN External address bus negative
33 I/O DM Differential data-minus USB
34 I/O DP Differential data-plus USB
35 I/O P0_5
36 I/O P3_0
37 I/O P3_1
38 I/O P3_3
39 I/O P3_6
40 I/O P0_2
41 I/O P2_0 System configuration pin along with EAN pins used to set the
42 I/O P2_7
43 P GND Ground reference
Legend: I= Input pin O= Output pin I/O= Input/Output pin P= Power pin
Note: All I/O pins can be configured using the UI tool, a Windows utility.
Configurable control or indication pin
(Internally pulled up, if configured as an input)
UART TX_IND, active-low (used by Bluetooth system to
wakeup the host MCU)
(Internally pulled low, if configured as an input)
• Slide switch detector, active-high
Configurable control or indication pin
(Internally pulled up, if configured as an input)
• Slide switch detector, active-high, Out_Ind_0
System configuration pin along with the P2_0 pins used to set
the module in any one of these modes:
• Application mode (for normal operation)
• Test mode (to change FW and EEPROM values)
• Mode setting, refer to Ta bl e 5- 1
Flash type module already installed internal pull down resistor
4.7 kOhm to GND
Configurable control or indication pin
(Internally pulled up, if configured as an input)
Volume-down key (default), active-low
Configurable control or indication pin
(Internally pulled up, if configured as an input)
Auxiliary input detector, active-low
Configurable control or indication pin
(Internally pulled up, if configured as an input)
REV key (default), active-low
Configurable control or indication pin
(Internally pulled up, if configured as an input)
FWD key (default), active-low
Configurable control or indication pin
(Internally pulled up, if configured as an input)
Multi-SPK Central/Peripheral mode control (firmware dependent)
Configurable control or indication pin
(Internally pulled up, if configured as an input)
Play/Pause key (default)
module in any one of the following modes:
• Application mode (for normal operation)
• Test mode (to change FW and EEPROM values)
• Mode setting, refer to Ta bl e 5- 1
Configurable control or indication pin
(Internally pulled up, if configured as an input)
Volume-up key (default), active-low
2021 Microchip Technology Inc. Advanced DS60001403G-Page 13
BM62/64
NOTES:
DS60001403G-Page 14 Advanced 2021 Microchip Technology Inc.
BM62/64
2.0 AUDIO
The input and output audios have different stages and
each stage can be programmed to vary the gain
response characteristics. For microphone, both single-ended inputs and differential inputs are supported.
To maintain a high quality signal, a stable bias voltage
source to the condenser microphone’s FET is provided.
The DC blocking capacitors can be used at both positive and negative sides of an input. Internally, this
analog signal is converted to 16-bit, 8/16 kHz linear
PCM data.
2.1 Digital Signal Processor
A Digital Signal Processor (DSP) is used to perform
speech and audio processing. The advanced speech
features, such as acoustic echo cancellation and noise
reduction are inbuilt. To reduce nonlinear distortion and
to help echo cancellation, an outgoing signal level to
FIGURE 2-1: SPEECH SIGNAL PROCESSING
the speaker is monitored and adjusted to avoid
saturation of speaker output or microphone input.
Adaptive filtering is also applied to track the echo path
impulse in response to provide echo free and
full-duplex user experience.
The embedded noise reduction algorithm helps to
extract clean speech signals from the noisy inputs
captured by the microphones and improves mutual
understanding in communication.
The advanced audio features, such as multi-band
dynamic range control, parametric multi-band equalizer, audio widening and virtual bass are inbuilt. The
audio effect algorithms improve the user’s audio
listening experience in terms of better audio quality
after audio signal processing.
Figure 2-1 and Figure 2-2 illustrate the processing flow
of speakerphone applications for speech and audio signal processing.
FIGURE 2-2: AUDIO SIGNAL PROCESSING
2021 Microchip Technology Inc. Advanced DS60001403G-Page 15
BM62/64
Note: The data corresponds to the 16 Ohm load with 2.8V operating voltage at +25°C room temperature.
Note: The data corresponds to the 16 Ohm load with 2.8V operating voltage at +25°C room temperature.
The DSP parameters can be configured using the DSP
tool. For additional information on the DSP tool, refer to
the “IS206X DSP Application Note”.
Note: The DSP tool and “IS206X DSP Applica-
tion Note” document, are available for
download from the Microchip website at:
www.microchip.com/BM62 and
www.microchip.com/BM64.
FIGURE 2-3: CODEC DAC DYNAMIC RANGE
2.2 Codec
The built-in codec has a high signal-to-noise ratio
(SNR) performance and it consists of an ADC, a DAC
and an additional analog circuitry.
Note: The internal codec supports 16-bit resolu-
tion; by adding trailing zeros in LSBs
2
24-bit I
Figure 2-3 through Figure 2-6 illustrate the dynamic
range and frequency response of the codec.
S port requirements can be met.
FIGURE 2-4: CODEC DAC THD+N VERSUS INPUT POWER
DS60001403G-Page 16 Advanced 2021 Microchip Technology Inc.
FIGURE 2-5: CODEC DAC FREQUENCY RESPONSE (CAPLESS MODE)
Note: The DAC frequency response corresponds to Single-ended mode with a 47 μF DC block capacitor.
BM62/64
FIGURE 2-6: CODEC DAC FREQUENCY RESPONSE (SINGLE-ENDED MODE)
2021 Microchip Technology Inc. Advanced DS60001403G-Page 17
BM62/64
2.3 Auxiliary Port
The BM62/64 module supports one analog (line-in) signal from the external audio source. The analog (line-in)
signal can be processed by the DSP to generate
different sound effects (multi-band dynamic range
compression and audio widening), which can be
configured by using the DSP tool.
2.4 Analog Speaker Output
The BM62/64 module supports the following analog
speaker output modes:
• Capless mode — Recommended for headphone
applications in which capless output connection
helps to save the BOM cost by avoiding a large
DC blocking capacitor. Figure 2-7 illustrates the
analog speaker output capless mode.
• Single-ended mode — Used for driving an external audio amplifier where a DC blocking capacitor
is required. Figure 2-8 illustrates the analog
speaker output single-ended mode.
FIGURE 2-7: ANALOG SPEAKER OUTPUT CAPLESS MODE
FIGURE 2-8: ANALOG SPEAKER OUTPUT SINGLE-ENDED MODE
DS60001403G-Page 18 Advanced 2021 Microchip Technology Inc.
NOTES:
BM62/64
2021 Microchip Technology Inc. Advanced DS60001403G-Page 19
BM62/64
3.0 TRANSCEIVER
The BM62/64 module is designed and optimized for the
Bluetooth 2.4 GHz system. It contains a complete radio
frequency transmitter/receiver section. An internal synthesizer generates a stable clock for synchronizing with
another device.
3.1 Transmitter
The internal power amplifier (PA) has a maximum output power of +4 dBm. This is applied for Class 2 or
Class 3 radios without an external RF PA.
The transmitter performs the IQ conversion to minimize
the frequency drift.
3.2 Receiver
The Low-Noise Amplifier (LNA) operates with TR-combined mode for single port application. It can save a pin
on the package without having an external Tx/Rx
switch.
The ADC is used to sample the input analog signal and
convert it into a digital signal for demodulator analysis.
A channel filter has been integrated into the receiver
channel before the ADC, which is used to reduce the
external component count and increase the anti-interference capability.
The image rejection filter is used to reject the image frequency for low-IF architecture. This filter for low-IF
architecture is intended to reduce external Band Pass
Filter (BPF) component for a super heterodyne
architecture.
The Received Signal Strength Indicator (RSSI) signal
feedback to the processor is used to control the RF
output power to make a good trade-off for effective
distance and current consumption.
BDR, symbol 1 represents 1-bit. However, each symbol in the payload part of EDR packet represents 2/3
bits. This is achieved by using two different modulations, π/4 DQPSK and 8 DPSK.
3.5 Adaptive Frequency Hopping
(AFH)
The BM62/64 module has an AFH function to avoid RF
interference. It has an algorithm to check the nearby
interference and to choose clear channel for
transceiver Bluetooth signal.
3.3 Synthesizer
A synthesizer generates a clock for radio transceiver
operation. There is a VCO inside with a tunable internal
LC tank that can reduce variation for components. A
crystal oscillator with an internal digital trimming circuit
provides a stable clock for the synthesizer.
3.4 Modem
For Bluetooth 1.2 specification and below, 1 Mbps was
the standard data rate based on the Gaussian Frequency Shift Keying (GFSK) modulation scheme. This
basic rate modem meets Basic Data Rate (BDR)
requirements of Bluetooth 2.0 with Enhanced Data
Rate (EDR) specifications.
For Bluetooth 2.0 and above specifications, EDR has
been introduced to provide the data rates of
1/2/3 Mbps. For baseband, both BDR and EDR utilize
the same 1 MHz symbol rate and 1.6 kHz slot rate.
DS60001403G-Page 20 Advanced 2021 Microchip Technology Inc.
For
NOTES:
BM62/64
2021 Microchip Technology Inc. Advanced DS60001403G-Page 21
BM62/64
4.0 POWER MANAGEMENT UNIT
The on-chip Power Management Unit (PMU) has two
main features: lithium-ion and lithium-polymer battery
charger, and voltage regulator. A power switch is used
to switch over the power source between the battery
and an adapter. Also, the PMU provides current to
drive two LEDs.
FIGURE 4-1: BATTERY CHARGING CURVE
4.1 Charging a Battery
The BM62/64 module has a built-in battery charger,
which is optimized for lithium-ion and lithium-polymer
batteries.
The battery charger includes a current sensor for
charging control, user-programmable current regulation, and high accuracy voltage regulation.
The charging current parameters are configured by the
UI tool. Reviving, pre-charging, constant current and
constant voltage modes, and re-charging functions are
included. The maximum charging current is 350 mA.
Figure 4-1 illustrates the charging curve of a battery.
4.2 Voltage Monitoring
A 10-bit, successive approximation register ADC (SAR
ADC) provides a dedicated channel for battery voltage
level detection. The warning level can be programmed
by using the UI tool. The ADC provides a granular resolution to enable the external MCU to take control over
the charging process.
DS60001403G-Page 22 Advanced 2021 Microchip Technology Inc.
4.3 LED Drivers
Two dedicated LED drivers control the LEDs.They provide enough sink current (16 step control and 0.35 mA
for each step), thus LEDs can be connected directly
with the BM62/64 module. The LED settings can be
configured using the UI tool.
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