WT32i BLUETOOTH AUDIO MODULE
DATA SHEET
Tuesday, 22 July 2014
Version 1.21
Copyright © 2000-2014 Bluegiga Technologies
All rights reserved.
Bluegiga Technologies assumes no responsibility for any errors which may appear in this manual.
Furthermore, Bluegiga Technologies reserves the right to alter the hardware, software, and/or specifications
detailed here at any time without notice and does not make any commitment to update the information
contained here. Bluegiga’s products are not authorized for use as critical components in life support devices
or systems.
The WRAP is a registered trademark of Bluegiga Technologies
The Bluetooth trademark is owned by the Bluetooth SIG Inc., USA and is licensed to Bluegiga Technologies.
All other trademarks listed herein are owned by their respective owners.
Bluegiga Technologies Oy
VERSION HISTORY
VERSION
COMMENT
1.0
First version
1.1
Added example how to protect the battery by shutting down the regulators at
certain voltage level
1.2
Fixed PCM pin numbering
1.21
Design check list added
Bluegiga Technologies Oy
TABLE OF CONTENTS
1
Design Check List..........................................................................................................................................7
2
WT32i Product Numbering ............................................................................................................................8
3
Block diagram ................................................................................................................................................9
4
Pinout and Terminal Description ................................................................................................................ 10
5
Electrical Characteristics ............................................................................................................................ 13
5.1
Absolute Maximum Ratings ................................................................................................................ 13
5.2
Recommended Operating Conditions ................................................................................................. 13
5.3
Digital Terminals.................................................................................................................................. 13
5.4
Audio Characteristics .......................................................................................................................... 14
5.4.1
ADC .............................................................................................................................................. 14
5.4.2
DAC .............................................................................................................................................. 15
5.4.3
A2DP Codecs............................................................................................................................... 15
5.5
5.5.1
RF Transceiver ............................................................................................................................ 17
5.5.2
Antenna Characteristics ............................................................................................................... 18
5.6
6
RF Characteristics ............................................................................................................................... 17
Current Consumption .......................................................................................................................... 21
Power Control and Regulation ................................................................................................................... 22
6.1
Protecting the Battery by Configuring the Module to Turn Off at Certain Voltage .............................. 24
6.2
Reset ................................................................................................................................................... 25
6.2.1
Internal POR ................................................................................................................................ 25
7
Battery Charger .......................................................................................................................................... 27
8
GPIO and AIO Functions ............................................................................................................................ 28
8.1
iWRAP supported GPIO Functions ..................................................................................................... 28
8.2
Outputting Internal Clocks ................................................................................................................... 28
8.3
Auxiliary ADC ...................................................................................................................................... 29
8.4
Software I2C Interface ........................................................................................................................ 29
9
Serial Interfaces.......................................................................................................................................... 30
9.1
UART Interface.................................................................................................................................... 30
9.1.1
Resetting Through UART Break Signal ....................................................................................... 31
9.1.2
UART Configuration While Reset is Active .................................................................................. 31
9.1.3
UART Bypass Mode .................................................................................................................... 31
9.2
USB Interface ...................................................................................................................................... 32
9.3
Programming and Debug Interface (SPI) ............................................................................................ 33
10
Audio Interfaces ...................................................................................................................................... 34
10.1
Stereo Audio Codec Interface ...................................................................................................... 34
10.1.1
ADC .............................................................................................................................................. 34
10.1.2
DAC .............................................................................................................................................. 36
Bluegiga Technologies Oy
10.1.3
Microphone Input ......................................................................................................................... 37
10.1.4
Line Input ..................................................................................................................................... 38
10.1.5
Output Stage ................................................................................................................................ 39
10.1.6
Mono Operation ........................................................................................................................... 41
10.1.7
Side Tone ..................................................................................................................................... 41
10.2
PCM Interface .............................................................................................................................. 41
10.3
I2S Interface ................................................................................................................................. 41
10.4
IEC 60958 Interface ..................................................................................................................... 43
11
Design Guidelines ................................................................................................................................... 45
11.1
Audio Layout Guide ..................................................................................................................... 45
11.1.1
EMC Considerations .................................................................................................................... 45
11.1.2
Choosing Capacitors and Resistors ............................................................................................ 45
11.2
RF Layout Guide .......................................................................................................................... 46
11.3
Example Application Schematics ................................................................................................. 49
12
Physical Dimensions ............................................................................................................................... 53
13
Soldering Recommendations .................................................................................................................. 55
14
Package .................................................................................................................................................. 56
15
Certification Guidance for an End Product Using WT32i ....................................................................... 58
15.1
Bluetooth End Product Listing...................................................................................................... 58
15.2
CE Approval of an End-Product ................................................................................................... 58
15.3
FCC Certification of an End Product ............................................................................................ 59
15.3.1
Co-location with Other Transmitters ............................................................................................ 60
15.4
IC Certification of an End Product ............................................................................................... 60
15.5
MIC Japan Certification of an End Product .................................................................................. 60
16
WT32i Certifications ................................................................................................................................ 60
16.1
Bluetooth ...................................................................................................................................... 60
16.2
CE ................................................................................................................................................ 60
16.3
FCC .............................................................................................................................................. 61
16.4
IC .................................................................................................................................................. 62
16.4.1
IC .................................................................................................................................................. 62
16.5
MIC Japan .................................................................................................................................... 63
16.6
KCC (South-Korea) ...................................................................................................................... 63
16.7
Qualified Antenna Types for WT32i-E ......................................................................................... 63
17
Contact Information................................................................................................................................. 64
Bluegiga Technologies Oy
WT32i Bluetooth® Audio Module
DESCRIPTION
KEY FEATURES:
WT32i is an audio specific Bluetooth 3.0
module with excellent radio frequency
performance and enhanced audio features,
enabling a best in class Bluetooth audio
experience.
In
addition
to
a
certified Bluetooth radio and software stack,
WT32i also contains a DSP, stereo audio
codec, and battery charger making it ideal
for fixed and portable audio applications.
WT32i
includes
Bluegiga's
iWRAP6 Bluetooth stack software which
implements A2DP, AVRCP v.1.5 profiles
and supports aptX® and AAC audio codecs
for stereo audio applications. For hands-free
applications
iWRAP6
software
also
supports HFP v.1.6, HSP, MAP and
PBAP and CVC® echo cancellation software.
For data communications to Android and
iOS
applications
iWRAP6
also
implements Bluetooth Serial Port Profile
(SPP) and Apple iAP profiles. WT32i is an
ideal solution for developers who want to
quickly integrate the latest Bluetooth audio
technologies without the time and costs
typically involved with a Bluetooth audio
chipset design.
APPLICATIONS:
Bluetooth 3.0 compliant
Excellent Radio Performance
o Transmit power: +6.5 dBm
o Receiver sensitivity: -90 dBm
o Link budget: 96.5 dB
Integrated chip antenna
antenna connector
Audio features
or
U.FL
o Integrated DSP
o 16-bit stereo codec
o 44.1kHz ADC, 48kHz DAC
o Analog, I2S, PCM, SPDIF, and
microphone interfaces
®
o Optional aptX and AAC stereo
audio codecs
®
o Optional
cancellation
CVC echo
o Wide Band Speech
Built-in battery charger
UART host interface
802.11 co-existence interface
Stereo speakers and sound bars
10 software programmable IO pins
Hi-Fi devices
Operating voltage: 1.8V to 3.6V
Hands-free kits
Temperature range: -40C to +85C
Stereo headsets
Bluetooth, CE, FCC, IC, Korea and
Japan qualified
Integrated iWRAP6 Bluetooth stack
o 13 Bluetooth profiles
o Apple
iAP1
compatibility
Figure 1: WT32i Bluetooth Audio Module
Bluegiga Technologies Oy
and
iAP2
1 Design Check List
POWERING THE MODULE
Make sure that VRE_ENA is connected correctly
Use iWRAP command SET CONTROL VREGEN
command to configure the VREG_ENA pin
according to the HW
Reserve test points for SPI interface for
debugging and FW updates
Battery Voltage
(2.7V...4.4V)
VDD_BAT
VREG_ENA
On/Off cntrl
The internal power on reset does not work
properly if the host pulls the reset line low during
boot. To prevent this, place a diode to the reset
input.
IN
LDO
EN (1.8V...3.6V)
VDD_IO
Battery Voltage
(2.7V...4.4V)
VDD_BAT
VREG_ENA
Host CPU
On/Off cntrl
IN
LDO
EN (1.8V...3.6V)
VDD_IO
WT32i
GPIO
Reset
RF LAYOUT
Make sure that the layout for the antenna is done
as instrcucted.
Board edge
Min 15mm
Min 15mm
6mm
Metal clearance
area
GND plane indentation 2mm
GND plane indentation max 5.9 mm
AUDIO DESIGN AND LAYOUT
See the example schematics on pages 49 -52
Avoid using single ended audio traces. Always
use differential audio signaling when possible
Use solid GND plane and make sure that all the
GND pins are connected to it by placing a GND
via right next to any GND pins.
When routing single ended audio traces, make
sure that the return current (i.e. GND) follows the
traces all the way from start to the end
Differential audio
signalstarces
are traced
parallel
Differential
audio
are
routed
to make sure they have perfect common mode
symmetrically
and parallel
rejection . All the audio traces are routed on a
solid GND plane.
DO NOT COMPROMISE AUDIO ROUTING
Bluegiga Technologies Oy
2 WT32i Product Numbering
Product code
Description
WT32i-A-AI6
WT32i Bluetooth Module with internal chip antenna and iWRAP6 Bluetooth
software
WT32i-A-AI6-APTX
WT32i Bluetooth Module with internal chip antenna and aptX® audio codec
capable iWRAP6 Bluetooth software.
WT32i-A-AI6IAP
WT32i Bluetooth Module with internal chip antenna and Apple iAP capable
iWRAP6 Bluetooth software. Available only to Apple MFI licensees. Contact
sales@bluegiga.com for more information.
WT32i-E-AI6
WT32i Bluetooth Module with U.FL connector and iWRAP6 Bluetooth
software
WT32i-E-AI6-APTX
WT32i Bluetooth Module with U.FL connector and aptX® audio codec
capable iWRAP6 Bluetooth software.
WT32i-E-AI6IAP
WT32i Bluetooth Module with U.FL connector and Apple iAP capable
iWRAP6 Bluetooth software. Available only to Apple MFI licensees. Contact
sales@bluegiga.com for more information.
DKWT32i-A
WT32i development kit
Bluegiga Technologies Oy
3 Block diagram
Flash
BC05-MM
UART/USB
RAM
Antenna
Balanced
filtter
2.4
GHz
Radio
Baseband
DSP
PIO
I/O
Audio In/Out
MCU
PCM/I2S
Kalimba DSP
SPI
XTAL
Reset
circuitry
Figure 2: Block Diagram of WT32i
BC05-MM
The BlueCore®5-Multimedia External is a single-chip radio and baseband IC for Bluetooth 2.4GHz systems. It
provides a fully compliant Bluetooth v3.0 specification system for data and voice. BlueCore5-Multimedia
External contains the Kalimba DSP coprocessor with double the MIPS of BlueCore3-Multimedia External,
supporting enhanced audio applications.
XTAL
Ther reference clock of WT32i is generated with 26 MHz crystal. All BC05-MM internal digital clocks are
generated using a phase locked loop, which is locked to the frequency of either the 26 MHz crystal or an
internally generated watchdog clock frequency of 1kHz.
RESET CIRCUITRY
The internal reset circuitry keeps BC05-MM in reset during boot in order for the supply voltages to stabilize.
This is to prevent corruption of the flash memory during booting. Please see chapter 6.1 for more detailed
description.
BALANCED FILTER
The internal balanced filter provides optimal impedance matching and band pass filtering in order to achieve
lowest possible in-band and out-of-band emissions.
ANTENNA
The antenna is a ceramic chip antenna with high efficiency. The antenna is insensitive to surrounding
dielectric materials and requires only a small clearance underneath which makes it compatible with previous
WT32I designs and well suitable for designs with high density.
FLASH
16 Mbit flash memory is used for storing the Bluetooth protocol stack and Virtual Machine applications. It can
also be used as an optional external RAM for memory-intensive applications.
Bluegiga Technologies Oy
4 Pinout and Terminal Description
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
AUDIO_OUT_P_LEFT
AUDIO_OUT_N_LEFT
GND
AUDIO_OUT_P_RIGHT
AUDIO_OUT_N_RIGHT
AUDIO_IN_N_LEFT
AUDIO_IN_P_LEFT
GND
AUDIO_IN_N_RIGHT
AUDIO_IN_P_RIGHT
MIC_BIAS
GND
VDD_CHG
VDD_BAT
LED0
SPI_MOSI
SPI_MISO
SPI_CLK
SPI_NCSB
GND
GND
RESET
UART_NRTS
UART_NCTS
PIO8
PIO7
PIO6
PIO5
PIO4
PCM_IN
PCM_OUT
PCM_SYNC
PCM_CLK
18
19
20
21
22
23
24
25
26
27
28
29
30
VREG_ENA
GND
GND
GND
AIO0
AIO1
PIO0
PIO1
PIO2
PIO3
USB_DUSB_D+
PIO9
PIO10
UART_RXD
UART_TXD
VDD_IO
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
Figure 3: WT32i
Pin Number
Pin Name
Pad Type
Description
1
VREG_ENA
Input
SW configurable enable pin for the
internal regulators
2-4, 18, 31,
39, 43, 48
GND
GND
GND
17
VDD_IO
Power supply
1.7V - 3.6V power supply for the serial
interfaces and GPIOs
37
VDD_BAT
Power supply / Charger
output
2.7V - 4.4V supply voltage for the
internal regulators and output of the
battery charger
38
VDD_CHG
Power supply
Nominal 5V supply voltage for the
battery charger
Table 1: Supply Terminal Descriptions
Bluegiga Technologies Oy
Page 10 of 64
Pin
Number
Pin Name
19
RESET
5
AIO0
Pin Type
Description
RESET
Active high reset. If not used, leave floating. When
connected, make sure that the reset is either pulled
high or floating (connected to high impedance)
during boot.
Configurable I/O
AIO0 and AIO1 can be used to read the voltage
level through the internal ADC (refer to iWRAP
User Guide for details). AIO pins can also be
configured to be used as general digital IO pins
through PS settings. Internal clocks can be routed
out through AIO pins by setting corresponding PS
settings. Note that the AIO pins are powered from
internal 1.5V supply so the maximum voltage level
of the AIO pins is 1.5V.
General purpose IO's can be configured with
iWRAP for various functions. Each IO can be
configured individually as output or input with
strong or weak pull-up/-down. Using particular PS
setting GPIO pins can be used to implement WiFi
co-existence signaling between WT32i and a WiFi
radio. Software I2C interface can be implemented
for slow I2C functions such as configuring external
audio codec or display.
6
AIO1
7
8
9
10
13
14
22
23
24
25
26
PIO0
PIO1
PIO2
PIO3
PIO9
PIO10
PIO8
PIO7
PIO6
PIO5
PIO4
Configurable CMOS I/O
11
USB_D-
I/O
12
USB_D+
I/O
15
UART_RXD
CMOS Input, weak internal
pull-down
UART data input
16
UART_TXD
CMOS output, tristate,
weak internal pull-up
UART data output
20
UART_NRTS
CMOS output, tristate,
weak internal pull-up
UART request to send, active low
21
UART_NCTS
CMOS Input, weak internal
pull-down
UART clear to send, active low
32
SPI_NCSB
33
SPI_CLK
USB data minus
USB data plus with selectable internal 1.5k pull-up
resistor
CMOS Input, weak internal
pull-down
CMOS Input, weak internal
pull-down
SPI chip select
SPI clock
Bluegiga Technologies Oy
Page 11 of 64
34
SPI_MISO
35
SPI_MOSI
36
LED0
CMOS Input, weak internal
pull-down
CMOS output, tristate,
weak internal pull-down
SPI data input
SPI data output
Open drain output
LED driver
Table 2: Terminal Descriptions
Pin
Number
Pin Name
Pin Type
40
41
42
44
45
46
47
49
50
MIC_BIAS
AUDIO_IN_P_RIGHT
AUDIO_IN_N_RIGHT
AUDIO_IN_P_LEFT
AUDIO_IN_N_LEFT
AUDIO_OUT_N_RIGHT
AUDIO_OUT_P_RIGHT
AUDIO_OUT_N_LEFT
AUDIO_OUT_P_LEFT
Analog
Analog
Analog
Analog
Analog
Analog
Analog
Analog
Analog
27
PCM_IN / I2S IN
28
PCM_OUT / I2S_OUT
29
PCM_SYNC / I2S_WS
Bidirectional, weak
internal down
PCM sync or I2S word select. WT32i can
operate as a PCM/I2S master providing the
sync or as a slave receiving the sync
30
PCM_CLK / I2S_SCK
Bidirectional, weak
internal down
PCM or I2S clock. WT32i can operate as a
PCM/I2S master providing the clock or as
a slave receiving the clock.
Description
CMOS input, weak
internal pull-down
CMOS outptu, tristate,
weak internal pull-down
PCM or I2S data input
PCM or I2S data output
Table 3: Audio Terminal Descriptions
Bluegiga Technologies Oy
Page 12 of 64
5 Electrical Characteristics
5.1 Absolute Maximum Ratings
Storage temperature range
Operating temperature range
VDD_IO
VDD_BAT
VDD_CHG
Digital Terminal voltages
AIO voltages
Min
Max
Unit
-40
-40
-0.4
-0.4
-0.4
VSS - 0.4V
VSS - 0.4V
+85
+85
3.6
4.4
6.5
VDD + 0.4V
1.9V
°C
V
V
V
V
V
°C
Table 4: Absolute Maximum Ratings
5.2 Recommended Operating Conditions
Storage temperature range
Operating temperature range
VDD_IO
VDD_BAT
VDD_CHG
Digital Terminal voltages
AIO voltages
Min
Max
Unit
-40
-40
1.7
2.7
0
0
0
+85
+85
3.6
4.4
6.5
VDD
1.5V
°C
V
V
V
V
V
°C
Table 5: Recommended Operating Conditions
5.3 Digital Terminals
Input/Output Characteristic
Min
Max
Unit
VIL input logic level low
VIL input logic level high
-0.3
0.625 x VDD
0.25 x VDD
VDD + 0.3
V
V
VOL output logic level low, IOL = 4.0mA
VOL output logic level high, IOL = -4.0mA
Strong pull-up
Strong pull-down
Weak pull-up
Weak pull-down
0
0.75 x VDD
-100
10
-5
0.2
0.125
VDD
-10
100
-0.2
5
V
V
µA
µA
µA
µA
Table 6: Digital Terminal Characteristics
Bluegiga Technologies Oy
Page 13 of 64
5.4 Audio Characteristics
5.4.1
ADC
Parameter
Conditions
Min
Typ
Max
Unit
-
-
-
16
Bits
-
8
-
44.1
kHz
8kHz
-
79
-
dB
11.025kHz
-
77
-
dB
16kHz
-
76
-
dB
22.050kHz
32kHz
-
76
75
-
dB
dB
Resolution
Input Sample
Rate, Fsample
Fsample
Signal to Noise
Ratio, SNR
44.1kHz
-
75
-
dB
Input full scale at maximum gain (differential)
-
4
-
mV rms
Input full scale at minimum gain (differential)
-
800
-
mV rms
3dB Bandwidth
-
20
-
kHz
Microphone mode input impedance
-
6.0
-
kHz
THD+N @ 30mV rms input
-
0.04
-
%
Table 7: ADC characteristics
Bluegiga Technologies Oy
Page 14 of 64
5.4.2
DAC
Parameter
Conditions
Min
Typ
Max
Unit
-
-
-
16
Bits
-
8
-
48
kHz
8kHz
-
95
-
dB
11.025kHz
-
95
-
dB
16kHz
-
95
-
dB
22.050kHz
32kHz
-
95
95
-
dB
dB
44.1kHz
-
95
-
dB
-
750
-
mV rms
Resistive
16
-
O.C.
Ω
Capacitive
-
-
500
pF
THD+N 16Ω Load
-
-
0.1
%
THD+N 100Ω Load
-
-
0.01
%
Resolution
Output Sample
Rate, Fsample
Fsample
Signal to Noise
Ratio, SNR
Output Full Voltage Swing (differential)
Allowed Load
Table 8: DAC Characteristics
5.4.3
A2DP Codecs
5.4.3.1 SBC
SBC codec is the default codec used for Bluetooth A2DP connections. Any Bluetooth device supporting A2DP
audio profile supports SBC codec. SBC was originally design to provide reasonable good audio quality while
keeping low computational complexity. SBC does not require high bit rates. Thus it works sufficiently with
Bluetooth where the bandwidth and the processing power are limited.
5.4.3.2 aptX®
The aptX is widely used in high quality audio devices. aptX can provide dynamic range up to 120 dB and it
®
has the shortest coding delay (100ms) compared to aptX . Because of high
processing capacity requirement for encoding, WT32i does not support AAC as A2DP source. Thus WT32i
can be used for receiving (A2DP sink) AAC (from iPhone for example) but it cannot transmit AAC coded
audio.
Bluegiga Technologies Oy
Page 16 of 64
5.5 RF Characteristics
5.5.1
RF Transceiver
Transceiver characteristic
Min
Typ
Max
Maximum transmit power
Minimum transmit power
5
6.5
-17
8
Transmit power stability over the temperature range
dB
1
-90
-91
-86
-83
-84
-80
dBm
dBm
+/- 0.5
Transmit power variation within the BT band
RT
-40C
Sensitivity DH1
+85C
RT
-40C
Sensitivity 3DH5
+85C
Unit
dB
dBm
dBm
dBm
dBm
dBm
dBm
Table 9: Transceiver characteristics
Table 10: Power control of WT32i
Bluegiga Technologies Oy
Page 17 of 64
Band /
Frequency
Standard
Min
(AVG /
PEAK)
Unit
54 / 74
dBuV/m
54 / 74
dBuV/m
Band edge
2390MHz
54 / 74
dBuV/m
Band edge
2483.5MHz
54 / 74
dBuV/m
Band edge
2400MHz
(conducted)
-20
dBc
Band edge
2483.5MHz
(conducted)
-20
dBc
Band edge
2400MHz
-30
dBm
50 / 61
< 40 /
50
3rd harmonic
ETSI EN 300
328 transmitter
spurious
emissions
ETSI EN 300
328 receiver
spurious
emissions
Max
(AVG /
PEAK)
Limit by the Standard
(AVG / PEAK)
2nd harmonic
FCC part 15
transmitter
spurious
emissions
Typ
(AVG /
PEAK)
2nd harmonic
-35
-30
dBm
3rd harmonic
(2400 - 2479)
MHz