Laird BT85, BT850-ST, BT850-SA User Manual

A

User Guide

BT85x Series

Bluetooth v4.2 Dual-Mode USB HCI Module

Version 1.0

BT85x Series

Datasheet

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www.lairdtech.com/bluetooth

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R

EVISION HISTORY

Version Date Notes Contributor Approver

1.0 07 Nov 2017 Initial Release Jacky Kuo Jonathan Kaye

BT85x Series

Datasheet

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C

ONTENTS

1 Scope ....................................................................................................................................................... 4

2 Operational Description ........................................................................................................................... 4

3 Block Diagram and Descriptions ............................................................................................................... 5

4 Specifications ........................................................................................................................................... 6

5 Pin Definitions .......................................................................................................................................... 6

6 DC Electrical Characteristics ..................................................................................................................... 8

7 RF Characteristics ..................................................................................................................................... 8

8 Interface .................................................................................................................................................. 9

8.1. Global Coexistence Interface .................................................................................................................... 9

8.2. USB Interface ......................................................................................................................................... 10

8.3. PCM Interface ........................................................................................................................................ 10

8.3.1. Slot Mapping .......................................................................................................................................... 10

8.3.2. Frame Synchronization ........................................................................................................................... 10

8.3.3.

Data Formatting

....................................................................................................................................... 13

8.3.4. Wideband Speech Support ..................................................................................................................... 13

8.3.5. Multiplexed Bluetooth Over PCM ........................................................................................................... 14

8.3.6. Burst PCM Mode .................................................................................................................................... 14

8.4. I2S Interface............................................................................................................................................ 15

8.5. BSC (Cypress Serial Control) Master Interface ......................................................................................... 17

9 Antenna Performance ............................................................................................................................ 19

10 Mechanical Dimensions and Land Pattern .............................................................................................. 21

11 Implementation Note ............................................................................................................................. 22

11.1. PCB Layout on Host PCB ......................................................................................................................... 22

11.1.1. Antenna Keep-out and Proximity to Metal or Plastic .............................................................................. 22

11.1.2. USB Dongle Design Example Using BT850-SA .......................................................................................... 23

12 Application Note for Surface Mount Modules ........................................................................................ 24

12.1. Introduction ........................................................................................................................................... 24

12.2. Shipping ................................................................................................................................................. 24

12.2.1. Tray Package .......................................................................................................................................... 24

12.2.2. Tape and Reel Package Information ....................................................................................................... 25

12.3. Reflow Parameters ................................................................................................................................. 26

13 Japan (MIC) Regulatory .......................................................................................................................... 27

13.1. Antenna Information .............................................................................................................................. 27

14 FCC Regulatory ....................................................................................................................................... 28

15 Industry Canada Regulatory ................................................................................................................... 30

16 European Union Regulatory ................................................................................................................... 32

17 Ordering Information ............................................................................................................................. 33

17.1. General Comments ................................................................................................................................ 33

18 Bluetooth SIG Approvals......................................................................................................................... 33

19 Additional Assistance ............................................................................................................................. 35

BT85x Series

Datasheet

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1 S

COPE

This document describes key hardware aspects of the Laird BT85x Bluetooth HCI module and Adapter . This
document is mainly intended to assist device manufacturers and related parties with the integration of this
module into their host devices. Data in this document are drawn from several sources including data sheets for
the Cypress CYW20704A2.
Because the BT850-Sx is currently in development stage, this document is preliminary and the information in
this document is subject to change. Please contact Laird Technologies or visit the product page on the Laird
website to obtain the most recent version of this document.

BT850-SA

BT850-ST

BT851

2 O

PERATIONAL DESCRIPTION

The BT85x series of USB HCI modules and Adapter leverage the Cypress CYW20704 A2 chipset to provide
exceptionally low power consumption with outstanding range for OEMs needing both Classic Bluetooth and
Bluetooth Low Energy support. The Bluetooth v4.2 core specification shortens your development time and
provides enhanced throughput, security and privacy.

The BT850 modules are ideal when designers need both performance and minimum size. For maximum
flexibility in integration, they support a host USB interface, I2S and PCM audio interfaces, GPIO, and Cypress’GCI
coexistence (2-Wire). The modules provide excellent RF performance and identical footprint options for
integrated antenna or an external antenna via a trace pin.

These modules present a Bluetooth standard HCI interface with native support for Windows, Linux and Android
Bluetooth software stacks for operating system backed devices. The BT851 Pluggable USB Adapter with inbuilt
Bluetooth stack simply plugs into any Windows, Android or Linux device via external USB connection.

Additionally, Laird has partnered with Searan for support of their ultra small, flexible ‘dotstack’ platform for
embedded Cortex M3 and M4 implementations.

Features and Benefits

Application Areas



Bluetooth v4.

2 - Du

al Mode (Classic Bluetooth and BLE)

 Compact footprint
 2-wire Cypress Global Coexistence Interface (GCI)
 High antenna radiation gain and efficiency
 Good interference rejection for multi-com system (GSM/WCDMA)
 Class 1 output – 8 dBm
 USB, I2S, and PCM
 Industrial temperature range
 512 k EEPROM support
 Bluetooth Controller subsystem
 FCC, IC, CE, RCM and Giteki approvals



Medical devices

 ePOS terminals
 Barcode scanners
 Industrial cable replacement
 IoT Platforms Automotive

Diagnostic Equipment

 Personal Digital Assistants (PDA)

BT85x Series

Datasheet

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3 B

LOCK DIAGRAM AND DESCRIPTIONS

Figure 1: BT850 module block diagram

CYW20704A2

(Main chip)

The BT85x is based on CYW20704A2 dual mode chip. The chip is a single-chip radio with on-

chip LDO regulators and baseband IC for Bluetooth 2.4 GHz systems including EDR to 3 Mbps.

Dedicated signal and baseband processing is included for full Bluetooth operation. The chip

provides I2S/PCM and USB interfaces. There are two general purpose I/Os be configured for

proprietary of Cypress GCI used and a general purpose I/O can be configured for

scan/inquire/paging/data traffic of indicator. These three I/O pins are controlled by

firmware.

Antenna BT850-SA & BT851 – The antenna is a ceramic monopole chip antenna.

BT850-ST – Trace Pad provision for use with a range of certified External Antennas

Band Pass

Filter

The band pass filter filters the out-of-band emissions from the transmitter to meet the

specific regulations for type approvals of various countries.

EEPROM There are 512 k bits EEPROM embedded on the BT85x which can be used to store

parameters, such as BD_ADDR, USB enumeration information, maximum TX power, PCM

configuration, USB product ID, USB vendor ID, and USB product description. With that, the

BT850 module can support UHE/HCI Proxy mode.

Crystal The embedded 40 MHz crystal is used for generating the clock for the entire module.

BT85x Series

Datasheet

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4 S

PECIFICATIONS

Table 1: BT850 specifications

Categories Feature Implementation

Wireless

Specification

Bluetooth® V4.2 Dual Mode – BR / EDR / LE

Frequency 2.402 - 2.480 GHz

Maximum Transmit

Power

Class 1

+8 dBm from antenna

Receive Sensitivity -94 dBm

Range Circa 100 meters

Data Rates Up to 3 Mbps (over-the-air)

Host Interface USB Full speed USB 2.0

GPIO 3.3V for all general purpose I/Os

Operational Modes

HCI Host Controller Interface over USB

UHE USB HID Emulation

EEPROM 2-wire 512 K bits

Coexistence 802.11 (Wi-Fi) 2-Wire Cypress Global Coexistence Interface (GCI)

Supply Voltage Supply 3.3V +/-10%

Power

Consumption

Current

Idle Mode ~8 mA

File Transfer ~43 mA

Antenna Options Internal

External

Multilayer ceramic antenna

Trace Pad

Physical Dimensions

8.5 x 13 x 1.6 mm (BT850-Sx - modules)

16 x 43 x 11 (BT851 – USB dongle)

Environmental Operating -30° C to +85° C

Storage -40° C to +85° C

Miscellaneous

Lead Free Lead-free and RoHS-compliant

Warranty 1-Year warranty

Approvals Bluetooth® Controller Subsystem Approved

FCC/IC/CE/RCM/Giteki

All BT85x series

5 P

IN DEFINITIONS

Table 2: BT850 pin definitions

Pin No. Pin Name I/O Supply Domain

Description If Unused

1 NC NC

2 NC

3 GND GND Ground GND

4 USB_D+ Bidirectional

3V3 USB data plus N/A

BT85x Series

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Pin No. Pin Name I/O Supply Domain

Description If Unused

5 USB_D- Bidirectional

3V3 USB data negative N/A

6 GND GND Ground GND

7 NC NC

8 RESET Input 3v3

Active-low reset

input

N/A

9 3v3 Input 3v3

Module main DC

power supply,

Input to internal 1.2V

and 2.5V LDO

N/A

10 NC NC

11 GND GND Ground GND

12 GND GND Ground GND

13 GND GND Ground GND

14 GND GND Ground GND

15 GND GND Ground GND

16 GND GND Ground GND

17 RF

BT850-ST RF signal

output (50Ω)
BT850-SA No

connection

18 GND GND Ground GND

19

I2S_WS/PCM_SYNC Bidirectional

3V3 PCM sync/I2S word

select

NC

20 I2S_CLK/PCM_CLK Bidirectional

3V3 PCM/I2S clock NC

21 I2S_DI/PCM_IN Bidirectional

3V3 PCM/I2S data input NC

22 I2S_OUT/PCM_OUT Bidirectional

3V3 PCM/I2S data output

NC

23 NC NC

24 GND GND Ground GND

25

BT_SECI_IN Input 3V3 Coexistence data

input

NC

26

BT_SECI_OUT Output 3V3 Coexistence data

output

NC

27 NC NC

28

GPIO_5 Bidirectional

3V3 Programmable

input/output line

NC

Pin Definition Note:

b

For to meet the pin alignment of BT800, there are several pins which must be put to NC status

(No Connection).

The GPIO_5 controlled by the default firmware for the status of BT850 indications.

BT85x Series

Datasheet

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6 DC E

LECTRICAL CHARACTERISTICS

Table 3: Recommended operating conditions

Rating Min Max Unit

Storage temperature -40 +150

⁰

C

Operating Temperature -30 +85 ⁰C

3V3 Input 3.0 3.6 V

Table 4: Digital I/O characteristics

Normal Operation Min Typ. Max Unit

VIL Input Low Voltage (VDDO = 3.3V) - - 0.8 V

VIH Input High Voltage (VDDO = 3.3V) 2.0 - - V

VOL Output Low Voltage - - 0.4 V

VOH Output High Voltage 3V3-0.4 - - V

IIL Input Low Current - - 1.0 µA

IIH Input High Current - - 1.0 µA

IOL Output Low Current

(VDDO = 3.3V, VOL = 0.4V)

- - 2.0 mA

IOH Output Low Current

(VDDO = 3.3V, VOH = 2.9V)

- - 2.0 mA

CIN Input Capacitance - - 0.4 pF

Table 5: Current consumption

Normal Operation Peak (8 dBm)

AVG Unit

Idle - 8 mA

Inquiry 23 22 mA

File Transfer 43 26 mA

LE Connected (Master) 26 - mA

LE Scan (Master) 26 - mA

LE File Transfer 27 26 mA

7 RF C

HARACTERISTICS

Table 6: BDR/EDR/LE transmitter characteristics (Input = 3V3 @ 25

℃℃℃℃

)

Parameter Min Typ. Max BT. Spec. Unit

GFSK Maximum RF Transmit Power 6 8 10 20 dBm

EDR Maximum RF Transmit Power 2 4 6 20 dBm

RF power variation over temperature range - 2.0 - - dB

RF power variation over BT band - 2 - - dB

RF power control step 2 4 8 - dB

BT85x Series

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Parameter Min Typ. Max BT. Spec. Unit

Initial Carrier Frequency Tolerance - 10 -

±

75 kHz

20 dB Bandwidth - 920 - 1000 kHz

In-Band Spurious

Emissions

1.0 MHz < |M-N| < 1.5 MHz - - -39 -26 dBc

1.5 MHz < |M-N| < 2.5 MHz - - -39 -20 dBm

|M-N| ≧ 2.5 MHz - - -47 -40 dBm

Drift rate - 10 - +/-25 kHz

∆

F

1Avg

- 152 - 140<>175

kHz

∆

F

2Max

100 - - 99.9 %

∆

F

2Avg

/

∆F

1Avg

- 1.0 - ≧ 0.8

LE ∆F

1Avg

- 245 - 225<>275

kHz

LE ∆F

2Max

100 - - 99.9 %

LE ∆F

2Avg

/ ∆F

1Avg

- 1.0 -

≧

0.8

Table 7: BDR/EDR/LE receiver sensitivity (Input = 3V3 @ 25

℃℃℃℃

)

Parameter Conditions Min Typ. Max BT. Spec. Unit

Sensitivity

GFSK, 0.1% BER, 1Mbps -90 -70 dBm

π/4-DQPSK, 0.01% BER, 2Mbps -94 -70 dBm

8-DPSK, 0.01% BER, 3Mbps -87 -70 dBm

GFSK, 30.8% PER, 1Mbps -94 -70 dBm

Sensitivity variation All Modulations (Over BT band) 2 dB

8 I

NTERFACE

8.1. Global Coexistence Interface

The BT850-Sx supports the proprietary Cypress Global Coexistence Interface (GCI) which is a two-wire interface.

The following key features are associated with the interface:

 Enhanced coexistence data can be exchanged over GCI_SECI_IN and GCI_SECI_OUT a two-wire interface,

one serial input (GCI_SECI_IN), and one serial output (GCI_SECI_OUT). The both pins are controlled by the
configuration file that is stored in EEPROM from the host.

 It supports generic UART communication between WLAN and Bluetooth devices.
 To conserve power, it is disabled when inactive.
 It supports automatic resynchronization upon waking from sleep mode.
 It supports a baud rate of up to 4 Mbps.

Error! Reference source not found. shows the 2-wire BT coexistence interface assignments.

Table 8: BT GCI two-wire coexistence

Coexistence Signal Name Signal Assignment Pin Number

BT_SECI_IN GPIO_6 B6

BT_SECI_OUT GPIO_7 C6

BT85x Series

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8.2. USB Interface

BT85x has a full-speed (12 Mbps) USB interface for communicating with other compatible digital devices. The
USB interface on the BT85x acts as a USB peripheral, responding to requests from a master host controller.

BT85x supports the Universal Serial Bus Specification (USB v2.0 Specification) and USB Battery Charging
Specification, available from http://www.usb.org. For more information on how to integrate the USB interface
on BT85xd, see Figure 15 located in the following section: USB Dongle Design Example Using BT850.

The following USB interface features are supported:

 USB Protocol, revision 2.0, full-speed compliant with LPM support (up to 12 Mbps)
 Bluetooth HCI
 HID, DFU, UHE (proprietary method to emulate an HID device at system boot)
 Integrated detach resistor
 USB termination when interface is not in use
 Internal modules, certification, and non-specification compliant operation

8.3. PCM Interface

The BT850-Sx supports two independent PCM interfaces that share the pins with I2S interfaces. The PCM
interface on the BT850-Sx can connect to linear PCM Codec devices in master or slave mode. In master mode,
the BT850-Sx generates the PCM_CLK and PCM_SYNC signals; in slave mode, these signals are provided by
another master on the PCM interface and are inputs to the BT850-Sx.

The configuration of the PCM interface may be adjusted by the host through the use of vendor-specific HCI
commands.

8.3.1. Slot Mapping

The BT850-Sx supports up to three simultaneous full-duplex SCO or eSCO channels through the PCM interface.
These three channels are time-multiplexed onto the single PCM interface by using a time-slotting scheme where
the 8 kHz or 16 kHz audio sample interval is divided into as many as 16 slots. The number of slots is dependent
on the selected interface rate of 128 kHz, 512 kHz, or 1024 kHz. The corresponding number of slots for these
interface rate is 1, 2, 4, 8, and 16, respectively. Transmit and receive PCM data from an SCO channel is always
mapped to the same slot. The PCM data output driver tristates its output on unused slots to allow other devices
to share the same PCM interface signals. The data output driver tristates its output after the falling edge of the
PCM clock during the last bit of the slot.

8.3.2. Frame Synchronization

The BT850-Sx supports both short- and long-frame synchronization in both master and slave modes. In short­frame synchronization mode, the frame synchronization signals an active-high pulse at the audio frame rate that
is a single-bit period in width and is synchronized to the rising edge of the bit clock. The PCM slave looks for a
high on the falling edge of the bit clock and expects the first bit of the first slot to start at the next rising edge of
the clock.

Figure 2 and Table 9 shows PCM Timing Diagram and Specifications for the master mode of short-frame.

BT85x Series

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Figure 2: PCM timing diagram (Short-Frame Sync, Master Mode)

Table 9: PCM Interface timing specifications (Short-Frame Sync, Master Mode)

Ref No.

Characteristics Minimum Typical Maximum Unit

1 PCM bit clock frequency - - 12 MHz

2 PCM bit clock LOW 41 - - ns

3 PCM bit clock HIGH 41 - - ns

4 PCM_SYNC setup 0 - 25 ns

5 PCM_OUT delay 0 - 25 ns

6 PCM_IN setup 8 - - ns

7 PCM_IN hold 8 - - ns

8

Delay from rising edge of PCM_BCLK during last bit

period to PCM_OUT becoming high impedance

0 - 25 ns

Figure 3 and Table 10 shows PCM Timing Diagram and Specifications for the slave mode of short-frame.

Figure 3: PCM timing diagram (Short-Frame Sync, Slave Mode)

Table 10: PCM Interface timing specifications (Short-Frame Sync, Slave Mode)

Ref No.

Characteristics Minimum Typical Maximum Unit

1 PCM bit clock frequency - - 12 MHz

2 PCM bit clock LOW 41 - - ns