Bluetooth Smart Ready Audio Module Revised 746421 1/AUG/216 23.9mm 2.3mm 16mm Features Bluetooth Smart Ready (Bluetooth Classic and Bluetooth Smart ) Low Power Consumption IC Antenna Onboard BR/ EDR & GATTBased Profiles HSP, HFP, A2DP, ARCP, PBAP, MAP and SPP (Profiles supported) Bluetooth Classic/ Smart Application Support 8 digital and 2 analogue I/O Microphone input and Speaker output interfaces 23.9mm x 16mm x 2.3mm SMT Side and Bottom Pads for easy production SIG Certified Solution CE, RoHS, REACH and WEEE Compliant Solution Integrated 16bit Stereo Audio CODEC SBC, MP3 and AAC decoder aptx codec (including support for SCMST) and Faststream codec CSR s cc technology for noisecancellation I2S, PCM and SPDIF Audio Interfaces UART and USB 2. (Full Speed) Serial Interfaces 6 Capacitive touch sensor input interfaces LCD segment driver Individual PWM blocks (3 on dedicated LED pads) Applications Wireless Headphones and Speakers Wired or wireless speakers Handfree Headsets Automotive Infotainment systems Home Entertainment Devices Audio Adapters Overview The Bluetooth Smart Ready audio module is an extremely versatile and cost effective solution. Enabling audio data to be wirelessly communicated between audio devices. Using a Bluetooth classic and Bluetooth Smart (LE) connection. It s sound enhancement features, makes it a perfect fit within your premium audio device. The sound enhancement features includes CSR s aptx audio technology. Providing CDlike quality over a Bluetooth connection. And CSR s cc audio technology for noise cancellation. Perfectly suited to wireless headphones, speakers and handfree headsets. This standalone module allows the developer to connect a microphone, speakers, capacitive touch sensors, LCD segment displays and other I/O devices. Running the user application without using an external MCU. LM offer application support to the developer and can create new user applications for the module. Your developed user application and settings can be preloaded to the, simplifying the manufacturing and testing process. It s SMT side and bottom pads allows for easy integrations into your embedded system. Page 1 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 Packaging Options 746421 Module 1 x SMT Plug & Play IC Ant Module Tray General Specification Wireless Bluetooth Standard Firmware OS Compatibility Profiles Profiles Supported v4.1 (Backwards Compatible) Programmable Standalone (Embedded Bluetooth Stack) BR / EDR and GATTBased HSP, HFP, A2DP, ARCP, PBAP, MAP and SPP Hardware Chipset Antenna Flash Memory RAM Program Interface Interfaces Audio Interfaces Power Supply Crystal Oscillators CSR IC Antenna Onboard 16 MB 56 KB SPI UART, PWM, USB 2. (Full Speed), PIO and AIO I2S, PCM and SPDIF 33 (BAT) or 5 (CHG) 26 MHz RF Characteristics Tx Output Power Rx Sensitivity Bandwidth/ Speed Frequency 2 m (Bluetooth Classic) 9 m (Bluetooth Classic) Up to 3Mbps 2.4 GHz to 2.485 GHz Physical Characteristics Operating Temperature Dimensions (L x W x H) Weight Certifications Compliance 2 C to +75 C 23.9mm x 16mm x 2.3mm.9 g SIG CE, RoHS, REACH and WEEE Page 2 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 Pin Outs 55 36 35 21 Pin 1 2 Pin Assignments Pin Name e Supply Domain Description 1 GND Ground Common Ground 2 AIO1 Bidirectional DD_AUX (1.35) input/output 3 AIO Bidirectional DD_AUX (1.35) input/output 4 CAP_SENSE_ DD_AUDIO_DR (18_SMPS) Capacitive touch sensor input 5 CAP_SENSE_1 DD_AUDIO_DR (18_SMPS) Capacitive touch sensor input 6 CAP_SENSE_2 DD_AUDIO_DR (18_SMPS) Capacitive touch sensor input 7 CAP_SENSE_3 DD_AUDIO_DR (18_SMPS) Capacitive touch sensor input 8 CAP_SENSE_4 DD_AUDIO_DR (18_SMPS) Capacitive touch sensor input 9 CAP_SENSE_5 DD_AUDIO_DR (18_SMPS) Capacitive touch sensor input 1 SD_IN & SPDIF_IN Bidirectional with weak pulldown I2S Interface & SPDIF Interface Sync data output. Alt PIO_17 11 SD_OUT & SPDIF_OUT Bidirectional with weak pulldown I2S Interface & SPDIF Interface Sync data output. Alt PIO_18 12 WS Bidirectional with weak pulldown I2S Interface & SPDIF Interface Sync data output. Alt PIO_19 13 SCK Bidirectional with weak pulldown I2S Interface & SPDIF Interface Sync data output. Alt PIO_2 14 SPI_CLK Input with strong pulldown SPI clock 15 SPI_MOSI Input with weak pulldown Master out slave in (SPI) 16 SPI_MISO Output with strong pullup Master in slave out (SPI) 17 SPI_CS# Input with weak pulldown Chip select for SPI, active low 18 RESET Input with strong pullup Reset if low. Pull low for minimum 5ms for reset. 19 UART_RX Bidirectional strong pullup UART data input 2 GND Ground Common Ground 21 UART_TX Bidirectional weak pullup UART data output 22 LED Open drain output LED Driver Page 3 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 Pin Assignments Continued Pin Name e Supply Domain Description 23 LED1 Open drain output LED Driver 24 LED2 Open drain output LED Driver 25 PIO Bidirectional with weak pulldown Programmable input / output line 26 PIO1 Bidirectional with weak pulldown Programmable input / output line 27 PIO2 Bidirectional with weak pulldown Programmable input / output line 28 PIO3 Bidirectional with weak pulldown Programmable input / output line 29 PIO4 Bidirectional with weak pulldown Programmable input / output line 3 PIO5 Bidirectional with weak pulldown Programmable input / output line 31 PIO6 Bidirectional with weak pulldown Programmable input / output line 32 PIO7 Bidirectional with weak pulldown Programmable input / output line 33 USB_DP Bidirectional 33_USB USB data plus 34 USB_DN Bidirectional 33_USB USB data minus 35 DD Positive supply for PIO 36 GND Ground Common Ground 37 18_SMPS DD 18 Output 38 BAT Battery terminal +ve Lithium ion/polymer battery positive terminal. Battery charger output and input to switch mode regulator. 39 BAT_SENSE Battery charger sense input 4 CHG Charger input Lithium ion/polymer battery charger input 41 CHG_EXT External charger control Otherwise leave unconnected 42 REG_ENABLE Regulator enable input 43 UART_CTS Bidirectional weak pulldown UART clear to send, active low. 44 UART_RTS Bidirectional weak pullup UART request to send, active low. Alt PIO16. 45 MIC_LN DD_AUDIO (1.35) Microphone input negative, left. 46 MIC_LP DD_AUDIO (1.35) Microphone input positive, left. 47 MIC_BIAS_A BAT/33_USB Microphone bias A 48 MIC_RN DD_AUDIO (1.35) Microphone input negative, right 49 MIC_RP DD_AUDIO (1.35) Microphone input positive, right 5 MIC_BIAS_B BAT/33_USB Microphone bias B 51 SPKR_RN DD_AUDIO_DR (18_SMPS) Speaker output negative, right 52 SPKR_RP DD_AUDIO_DR (18_SMPS) Speaker output positive, right 53 SPKR_LN DD_AUDIO_DR (18_SMPS) Speaker output negative, left 54 SPKR_LP DD_AUDIO_DR (18_SMPS) Speaker output positive, left 55 GND Ground Common Ground Page 4 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 General Electrical Specification Absolute imum Ratings Recommended Operating Condition Storage Temperature 4 C +85 C Operating Temperature Range 2 C +75 C Supply oltage (CHG).4 5.75 Supply oltage (CHG) 4.75 / 3.1 5.75 Supply oltage (BAT).4 4.4 Supply oltage (BAT) 2.5 4.25 Supply oltage (BAT_SENSE).4 5.75 Supply oltage (BAT_SENSE) 4.25 Supply oltage (REG_ENABLE).4 4.4 Supply oltage (REG_ENABLE) 4.25 Supply oltage (LED [2:] ).4 4.4 Supply oltage (LED [2:] ) 1.1 4.25 Supply oltage ().4 3.6 Supply oltage () 1.7 3.6 1.8 Switchmode Regulator 1.8 Switchmode Regulator Input oltage (BAT) 2.8 3.7 4.25 Output oltage (18_SMPS) 1.7 1.8 1.9 Normal Operation Transient setting time 3 μs Load current 185 Current available for external use, stereo audio with 16Ω load (a) 25 Peak conversion efficiency 9 Switching frequency 3.63 4. 4. MHz Low Power Mode, automatically entered in Deep Sleep Transient setting time 2 μs Load current.5 5 Current available for external use 5 Peak conversion efficiency 85 Switching frequency 1 2 Regulator Enable REG_ENABLE, Switching Threshhold Rising Threshold 1. (a) = More current available for audio loads above 16Ω Page 5 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 Battery Charger Battery Charger Input oltage, CHG (a) 4.75 / 3.1 5. 5.75 (a) = Reduced specification from 3.1 to 4.75. Full specification > 4.75 Trickle Charge Mode Charge current Itrickle as percentage of fast charge current 8 1 12 fast rising threshold 2.9 fast rising threshold trim step size.1 fast falling threshold 2.8 Fast Charge Mode Charge current during constant headroom >.55 194 2 26 Current mode, Ifast headroom >.55 1 Reduced headroom charge current, as a percentage of Ifast Mid headroom =.15 5 1 ICTRL charge current step size 1 float threshold, calibrated 4.16 4.2 4.24 Standby Mode oltage hysteresis on BAT, hyst 1 15 m Error Charge Mode Headroom (a) error rising threshold 3 5 m Headroom (a) error threshold hysteresis 2 3 m (a) = Headroom = CHGBAT External Charge Mode Fast charge current Ifast 2 5 Control current into CHG_EXT 2 oltage on CHG_EXT 5.75 External pass device hfe 5 Sense voltage, between BAT_SENSE and BAT at max current 195 2 25 m (a) = In the external mode, the battery charger meets all the previous charger electrical characteristics and the additional or superceeded elecectrical characteristics are listed in this table Stereo Codec: to Digital Converter Parameter Conditions Resolution 16 Bits Input Sample Rate Fsample 8 48 SNR fin = 1 Fsample B/W = 2HzFsample/2 8 93 (2 max) 16 92 AWeighted 32 92 THD+N < 1 44.1 92 1.6pkpk input 48 92 Page 6 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 Stereo Codec: to Digital Converter Continued... Parameter Conditions THD+N fin = 1 B/W = 2HzFsample/2 Fsample (2 max) 8.4 1.6pkpk input 48.8 Digital gain Digital gain resolution = 1 / 32 24 21.5 gain Preamplifier setting 3 42 =, 9, 21 or 3 setting = 3 to 12 in 3 steps Stereo seperation (crosstalk) 89 Stereo Codec: Digital to Converter Parameter Conditions Resolution 16 Bits Output Sample Rate Fsample 8 96 SNR fin = 1 Fsample Load B/W = 2Hz2 AWeighted 48 1Ω 96 THD+N <.1 48 32Ω 96 FS input 48 16Ω 96 Parameter Conditions THD+N fin = 1 Fsample Load B/W = 2Hz2 FS input 8 1kΩ.2 8 32Ω.2 8 16Ω.3 48 1kΩ.3 48 32Ω.3 48 16Ω.4 Digital Gain Digital Gain Resolution = 1 /32 24 21.5 Gain Gain Resolution = 3 21 Stereo seperation (crosstalk) 88 Page 7 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 Digital Digital Terminals Input oltage IL input logic level low.4.4 IH input logic level high.7x +.4 Tr/Tf 25 ns Output oltage OL output logic level low, IOL = 4..4 IH output logic level high, IOH =.4.75x Tr/Tf 5 ns Input and Tristate Currents Strong pullup 15 4 1 ua Strong pulldown 1 4 15 ua Weak pullup 5 1..33 ua Weak pulldown.33 1. 5. ua CI input Capacitance 1. 5. pf LED Driver Pads LED Driver Pads Current, IPAD High impedance state 5 μa Current sink state 1 LED pad voltage, PAD IPAD = 1.55 LED pad resistance PAD <.5 4 Ω OL output logic level low(a) OH output logic level high(a).8 IL input logic level low IH input logic level high.8 (a) LED output port is opendrain and requires a pullup Auxiliary ADC Auxiliary ADC Resolution 1 Bits Input voltage range(a) 1.35 Accuracy INL 1 1 LSB (Guaranteed monotonic) DNL 1 LSB Offset 1 1 LSB Gain error.8.8 Input bandwidth 1 Conversion time 1.38 1.69 2.75 μs Sample rate(b) 7 Samples/s (a) LSB size = DD_AUX/123 (b) The auxiliary ADC is accessed through a M function. The sample rate given is achieved as part of this function. Page 8 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 Auxiliary DAC Auxiliary DAC Resolution 1 Bits Supply voltage, DD_DAC 1.3 1.35 1.4 Output voltage range 1.35 Fullscale output voltage 1.3 1.35 1.4 LSB size 1.32 2.64 m Offset 1.32 1.32 m Integral nonlinearity 1 1 LSB Settling time(a) 25 ns (a) The settling time does not include any capacitive load RF Specification: Temperature = +2 C Transmitter Bluetooth Specification imum RF transmit power 6 2 6 to +4 m RF power variation over temperature range with compensation enabled ±.5 RF power variation over temperature range with compensation disabled ±1.5 2 bandwidth for modulated carrier 925 1 1 Adjacent channel transmit power F = F ± 2MHz 23 2 2 m Adjacent channel transmit power F = F ± 3MHz 32 28 4 m Adjacent channel transmit power F = F ± > 3MHz 65 4 4 m f1avg imum Modulation 14 165 175 14<f1avg<175 f2max imum Modulation 115 137 115 f2avg/ f1avg.8.9.8 Initial carrier frequency tolerance 75 15 75 ±75 Drift Rate 5 2 2 /5μ Drift (single slot packet) 15 25 25 Drift (five slot packet) 15 4 4 2nd Harmonic Content 4 3 m 3rd Harmonic Content 55 3 m RF Specification: Temperature = +2 C Receiver Bluetooth Specification Sensitivity at.1 BER for all packet types 2.42 87 83 7 m 2.441 9 86 2.48 9 86 imum received signal at.1 BER 2 >1 2 m C/I cochannel 5 11 11 Adjacent channel selectivity C/I F = F + 1MHz 5 Adjacent channel selectivity C/I F = F 1MHz 3 Adjacent channel selectivity C/I 35 3 3 Page 9 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 RF Specification: Temperature = +2 C Continued... Receiver Bluetooth Specification F = F + 2MHz Adjacent channel selectivity C/I F = F 2MHz 25 2 2 Adjacent channel selectivity C/I F = F + 3MHz 45 4 4 Adjacent channel selectivity C/I F = F 5MHz 45 4 4 Adjacent channel selectivity C/I F = FImage 2 9 9 imum level of intermodulation interferers 39 23 39 m Spurious output level 155 m/hz 1. Serial Interface 1.1 USB Interface has a fullspeed (12Mbps) USB interface for communicating with other compatible digital devices. The USB interface on acts as a USB peripheral, responding to requests from a master host controller. contains internal USB termination resistors and requires no external resistor matching. supports the Universal Serial Bus Specification, Revision v2. (USB v2. Specification), supports USB standard charger detection and fully supports the USB Battery Charging Specification, available from http://www.usb.org. For more information on how to integrate the USB interface on see the Bluetooth and USB Design Considerations Application Note. As well as describing USB basics and architecture, the application note describes: Power distribution for high and low buspowered configurations Power distribution for selfpowered configuration, which includes USB BUS monitoring USB enumeration Electrical design guidelines for the power supply and data lines, as well as PCB tracks and the effects offerrite beads USB suspend modes and Bluetooth lowpower modes: Global suspend Selective suspend, includes remote wake Wake on Bluetooth, includes permitted devices and setup prior to selective suspend Suspend mode current draw PIO status in suspend mode Resume, detach and wake PIOs Battery charging from USB, which describes dead battery provision, charge currents, charging in suspend modes and USB BUS voltage consideration USB termination when interface is not in use Internal modules, certification and nonspecification compliant operation Page 1 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
I TECHNOLOGIES Bluetooth Smart Ready Audio Module 746421 1. Serial Interface 1.2 Programming and Debug Interface provides a debug SPI interface for programming, configuring (PS Keys) and debugging the. Access to this interface is required in production. Ensure the 4 SPI signals and the SPI line are brought out to either test points or a header. To use the SPI interface, the SPI line requires the option of being pulled high externally. 2. Interfaces 2.1 I/O Ports, AIO has 2 generalpurpose analogue interface pin, AIO[] & AIO[1]. ically, this connects to a thermistor for battery pack temperature measurements during charge control. 2.2 LED Drivers includes a 3pad synchronised PWM LED driver for driving RGB LEDs for producing a wide range of colours. All LEDs are controlled by firmware. The terminals are opendrain outputs, so the LED must be connected from a positive supply rail to the pad in series with a currentlimiting resistor. LED Forward oltage, F LED Resistor oltage Drop, R R LED LED[2, 1 or ] Pad oltage PAD R =2Ω ON Figure 2.1: LED Equivalent Circuit From Figure 2.1 it is possible to derive Equation 2.1 to calculate ILED. If a known value of current is required through the LED to give a specific luminous intensity, then the value of RLED is calculated. I LED = DD F R LED + R ON Equation 2.1: LED Current For the LED pads to act as resistance, the external series resistor, RLED, needs to be such that the voltage drop across it, R, keeps PAD below.5. Equation 2.2 also applies. DD = F + R + PAD Equation 2.2: LED PAD oltage Note: The LED current adds to the overall current. Conservative LED selection extends battery life. Page 11 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 3. Power Control and Regulation 3.1 oltage Regulator Enable When using the integrated regulators the voltage regulator enable pin, REG_ENABLE, enables the and the following regulators: 1.8 switchmode regulator 1.35 switchmode regulator Lowvoltage DD_DIG linear regulator Lowvoltage DD_AUX linear regulator The REG_ENABLE pin is active high. bootsup when the voltage regulator enable pin is pulled high, enabling the regulators. The firmware then latches the regulators on, it is then permitted to release the voltage regulator enable pin. The status of the REGENABLE pin is available to firmware through an internal connection. REGENABLE also works as an input line. 3.2 Reset, RST# is reset from several sources: RST# pin Poweron reset USB charger attach reset Software configured watchdog timer The RST# pin is an active low reset and is internally filtered using the internal low frequency clock oscillator. LM Developes recommends applying RST# for a period >5ms. At reset the digital I/O pins are set to inputs for bidirectional pins and outputs are set to tristate. 4. Battery Charger 4.1 Battery Charger hardware Operating Modes The battery charger hardware is controlled by the M. The battery charger has 5 modes: Disabled Trickle charge Fast charge Standby: fully charged or float charge Error: charging input voltage, CHG, is too low The battery charger operating mode is determined by the battery voltage and current. The internal charger circuit can provide up to 2 of charge current, for currents higher than this the can control an external pass transistor 4.2 External Mode The external mode is for charging higher capacity batteries using an external pass device. The current is controlled by sinking a varying current into the CHG_EXT pin, and the current is determined by measuring the voltage drop across a resistor, Rsense, connected in series with the external pass device, see Figure 4.2.1. The voltage drop is determined by looking at the difference between the BAT_SENSE and BAT pins. The voltage drop across Rsense is typically 2m. The value of the external series resistor determines the charger current. This current can be trimmed with a PS Key. In Figure 4.2.1, R1 (22mΩ) and C1 (4.7μF) form a RC snubber that is required to maintain stability across all battery ESRs. The battery ESR must be <1.Ω Page 12 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 4. Battery Charger Continued... Figure 4.2.1: Battery Charger External Mode ical Configuration CHG BUS CHG_EXT BAT_SENSE TR 1 External Pass Device CHG_EXT 1 BAT_SENSE 2 3 Q1 BCX51 C15 4u7 BAT R1 22mΩ C1 4.7uF + R sense BAT 1 Li+ Cell BAT R14 1 4mR R18 22mR Figure 4.2.2: Optional Ancilliary Circuits In Figure 4.2.2, Optional fast charge,4mω = 5m. Connect BAT_SENSE to BAT if not using this circuit. 5. Flash Memory 5.1 eflash Memory The internal flash memory provides 16Mb of internal code and data storage. For improved performance, the internal flash memory has 45ns access time and is organised as 64bit wide. 5.2 Serial Quad I/O Flash (Optional) supports serial flash. This enables additional data storage areas for device specific data. use the Serial Quad I/O Flash 4Mb Flash. 6. Capacitive Touch Sensor capacitive touch sensor interface features: Support for up to 6 capacitive touch sensing electrodes: Printed on the PCB Made from flex PCB Configuration for individual buttons Configuration for a wipetype arrangement where 2 or more pads sense taps at each end or a wipe from one side to the other Operates in deep sleep and is a programmable source for wakeup Figure 6.1 shows the system block diagram for the capacitive touch sensor interface. The interface depends on the capacitive touch sensor type. Therefore the overall control of the capacitive touch sensor interface resides in the M, so it is easily modified in each enduser application. Page 13 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 Figure 6.1 shows the system block diagram for the capacitive touch sensor interface. The interface depends on the capacitive touch sensor type. Therefore the overall control of the capacitive touch sensor interface resides in the M, so it is easily modified in each enduser application. CAP_SENSE[] CAP_SENSE[1] CAP_SENSE[2] CAP_SENSE[3] CAP_SENSE[4] Capacitive Range Control Sampling Fontend ADC Digital Processing CAP_SENSE[5] Firmware Figure 6.1: Capacitive Touch Sensor Block Diagram M The overall systemlevel specification for the capacitive touch sensor interface on the Module is: 6 inputs multiplexed in to 1 touch sensor on the frontend Capacitances of pf to 5pF measured with a resolution of 4fF, where a touch is assumed to be between ±5fF and ±1pF Each reading takes 172μs: 6 pads read every 1.3ms System autocalibrates to remove parasitic and environmental effects including: PCB construction Temperature Humidity Works in normal and deep sleep modes System current is approximately 5μA from the battery The touch sensor also functions like a PIO The system block diagram in Figure 6.1 highlights the toplevel architecture for the capacitive touch sensor interface, it consists of: Capacitive range control: Sets the rough capacitance of the touch sensor pad, which is product dependent Splits into 4 integrated capacitors The M selects which capacitors are enabled, i.e. the range capacitance Sampling front end: An internal capacitance is trimmed by the digital state machine ensuring: Touch Capacitance = Range Capacitance + Internal Capacitance When the internal capacitance is correctly trimmed: The sense voltage is A touch changes the touch capacitance, which then changes the sense voltage ADC: Uses a successive approximation, charge redistribution ADC Clocked at 64 9bit resolution, where LSB is ±2fF and full range is ±1pF The internal capacitance is a 7bit variable capacitor with 114fF steps and 14.5pF range Page 14 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 The internal capacitance is trimmed, putting it in the mid range of the ADC. This enables measurements from pf to 5pF, where a capacitive touch is between ±5fF and ±1pF. Digital signal conditioning: Only the enabled inputs are scanned Enabling fewer inputs increases readings per second Averaging of ADC readings reduces noise, this is software programmable from 1 to 64 readings in intervals to the power of 2 The internal capacitance updates using a rolling average of the ADC readings, software programmable from 1 to 215 readings in intervals to the power of 2. For example, 32768 readings take approximately: 5.6s if polling one pad (no averaging) 33.8s if polling 6 pads (no averaging) Pulse skipping mode is possible, reducing the current consumption. Here the system waits a programmable number of 64 clock cycles (maximum 29) before the next read, i.e. an 8ms maximum pause. ADC trigger level is software programmable. If the threshold is crossed the firmware gets an interrupt. 6 hardware event registers store the pad number and trigger time, which enables the system to sense swipes. Programmable hysteresis, with one value for all pads Software signal conditioning (firmware): The firmware reads ADC and Cint values after an interrupt as the hardware only stores the pad number and trigger time Digital state machine scans pads and calibrates the internal capacitance If a swipe happens in deep sleep the firmware reads the trigger order and event time when it wakes up. It then reads the last ADC reading for each input, not the reading that triggered the interrupt. M: Configures the hardware and gets an interrupt when a programmable threshold is crossed Selects the range capacitance Decides whether an event is a valid touch Page 15 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 Module Block Diagram CHG / BAT ANT SPI Filter BT_RF UART FLASH 16 MB SQIF 4 MB (Optional) CSR Chipset PIO USB PCM I 2 S SPDIF XTAL 26MHz Page 16 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 Physical Dimensions Top iew 55 36 35.6.9.9mm 16mm.9mm Pin Spacing Pin 1 2 1.7 5.6mm 22.7mm 23.9mm 1.2 Front iew 2.3mm 23.9mm Side iew 2.3mm 16mm Page 17 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 PCB Footprint Optimal Placement Position EDGE OF HOST PCB ( Optimal ) Pin 1 Placement Note If the optimal placement position cannot be achieved, ensure there is no metal beneath the highlighted part of module. NB Aim to place the module away from interference. (i.e: place the module at the edge of the board.) NO METAL BENEATH THIS AREA Pin 1 55 36 35.9.9 16mm Pin Spacing Pin 1 1.7 2 5.6mm 23.9mm Page 18 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com
Bluetooth Smart Ready Audio Module 746421 14mm Tray Dimensions 314mm Quantitites 1 Tray = 3 modules 1 Trays = 3 modules 2 Trays = 6 modules The trays are stacked and inserted into an antistatic vacuum bag and the AntiStatic Label, Model Name Label and Moisture Sensitive Labels stuck on. drying agent Humidity Indicator Card Antistatic aluminium vacuum bag. The vacuum bag is placed inside the box and a Model Name Label stuck on the frontside of each box. Model name label Antistatic aluminium vacuum bag. box ) box carton Each carton contains 4 boxes. carton label Page 19 of 19 +44() 27 428 2647 www.lmtechnologies.com sales@lmtechnologies.com