FOUNDATION™ Digital Single or Dual Channel DSP Compression System GA3216 PRELIMINARY DATA SHEET DESCRIPTION • efficient, high fidelity 1 or 2-channel WDRC signal processing The GA3216 hybrid is a trimmer-configurable DSP system based on a two-channel compression circuit. It can efficiently replace traditional hearing-aid compression circuits without compromising fundamental performance requirements. • fully programmable via serial data interface • four trimmer inputs plus volume control • flexible trimmer/parameter assignments A trimmer interface supports manual circuit configuration. It continuously monitors trimmer positions and translates them into the hearing-aid parameters of choice. A serial data interface provides full programmability both at the factory and in the field. • optional two-terminal or three-terminal trimmers • choice of wideband or independent 2-channel level detection • choice of two strategies for AGC-I parametric adjustment • 6, 12 or 24 dB/octave band split filter or configurable as single-channel compressor. • in-channel, low level squelch control (1:2 expansion) • output compression limiting (AGC-O) • flexible pre- and post-emphasis filters • four independent memories The GA3216 includes in-channel squelch to attenuate microphone and circuit noise in quiet environments. It also includes low-distortion compression limiting and programmable high and low cut filters as well as five configurable equalization filters. Unused blocks can be powered down to save battery current, for example, when using the device in single-channel mode. • pulse-density-modulated output stage drives zerobias 2-terminal receivers thinSTAX™ PACKAGING Hybrid typical dimensions: 0.190 x 0.123 x 0.060in (4.82 x 3.12 x 1.52mm) MS MS2 14 13 VREG2 19 VREG 1 SDA VB 12 11 PROGRAMMING INTERFACE EEPROM TONE GENERATOR REGULATOR TWIN DETECTOR COMPRESSOR HP IN 16 T 17 A/D TWIN DETECTOR T-coil EQ 24db/oct BAND SPLIT FILTER 1st to 3rd ORDER LC Σ 1st or 2nd ORDER EQ5 10 VBP HC SQUELCH EQ1 COMPRESSOR LP EQ4 D/A HBRIDGE PEAK CLIPPING 8 OUT+ 9 OUT - 7 PGND AGC-O EQ2 TWIN DETECTOR TWIN DETECTOR SQUELCH MGND 15 EQ3 VC GAIN TRIMMER INTERFACE GA3216 5 2 3 4 18 20 6 VC TR1 TR2 TR3 TR4 GND2 GND1 BLOCK DIAGRAM Doc.No.24501 - 1 [Rev. July 2003] 1 of 14 GA3216 FEATURES ABSOLUTE MAXIMUM RATING PAD CONNECTION VREG Operating Temperature Range -10°C to 40°C Storage Temperature Range -20°C to 70°C 25mW Input ESD Voltage 2000V 1 T Maximum Operating Supply Voltage IN 1.5VDC Absolute Maximum Supply Voltage TR2 2 TR3 VC GND1 4 5 6 3 PGND 7 17 16 18 19 20 TR4 VREG2 GND2 8 OUT+ 9 OUT - 2VDC 15 MGND 14 13 12 11 MS2 MS SDA VB CAUTION CAUTION ELECTROSTATIC SENSITIVE DEVICES LEVEL 3 MOISTURE SENSITIVE DEVICES DO NOT OPEN PACKAGES OR HANDLE EXCEPT AT A STATIC-FREE WORKSTATION DO NOT OPEN PACKAGES EXCEPT UNDER CONTROLLED CONDITIONS 10 VBP ELECTRICAL CHARACTERISTICS Conditions: Supply Voltage VB = 1.3V; Temperature = 25°C, 16 kHz bandwidth PARAMETER MIN TYP MAX UNITS ΙAMP All functions, 24kHz sampling rate - 540 - µA ΙAMP All functions, 32kHz sampling rate - 650 - µA Minimum Operating Supply Voltage VBOFF Ramp down 0.95 - 0.980 V Supply Voltage Turn on Threshold VBON Ramp up Hybrid Current SYMBOL CONDITIONS 1.065 1.10 1.160 V Supply Voltage Hysteresis VBON - VBOFF - 150 - mV Low Battery Warning Voltage Ramp down 1.06 1.10 1.14 V During Communication 1.20 1.30 - V Note 2 100k - - cycles Supply Voltage During Communication VBC EEPROM Burn Cycles Low Frequency System Bandwidth High Frequency System Bandwidth Total Maximum System Gain AV - 130 - Hz 32 kHz sampling frequency - 16 - kHz 24 kHz sampling frequency - 12 - kHz 82 83 84 dB VIN = -95 dBV @ 3kHz; squelch disabled See Note 1. Converter Gain ACONV 28 29 30 dB Total Harmonic Distortion THD VIN = -40 dBV - - 1 % THD at Maximum Input THDM VIN = -13 dBV, HRX - ON - - 3 % ƒclk 1.963 2.048 2.115 MHz VREG 0.87 0.90 0.93 V PSRRREG - 36 - dB Clock Frequency A/D + D/A gain. REGULATOR Regulator Voltage Regulator Supply Rejection VOLUME CONTROL AND TRIMMERS Volume Control or Trimmer Resistance RVC Two-Terminal Trimmer. See Note 3. Volume Control or Trimmer Resistance RVC Three-Terminal Trimmer. See Note 3. Volume Control Range ∆A - 200 - kΩ 0.1 - 1 MΩ - 48 - dB 2 of 14 24501 - 1 GA3216 Absolute Maximum Power Dissipation TR1 ELECTRICAL CHARACTERISTICS (Continued) Conditions: Supply Voltage VB = 1.3V; Temperature = 25°C, 16 kHz bandwidth PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS MS AND MS2 INPUT Pull Down/Up Resistance - 1 - MΩ Logic 1 Voltage - VREG - V Logic 0 Voltage - 0 - V Input Referred Noise IRN Input Impedance ZIN Crosstalk Bandwidth 100Hz - 8kHz Between microphone and telecoil inputs Maximum Input Level - - -108 dBV 13.5 16 18.5 kΩ - -60 - dB - -13 - dBV Input Dynamic Range HRX - ON, Bandwidth 100Hz - 8kHz - 95 - dB A/D Dynamic Range Bandwidth 100Hz - 8kHz - 86 - dB 0dBFS ƒ = 1kHz - -1 - dBV Bandwidth 100Hz - 8kHz - 83 - dB - 10 20 Ω OUTPUT Maximum RMS Output Voltage D/A Dynamic Range Output Impedance ZOUT SDA INPUT Logic 0 Voltage Note 2 0 - 0.3 V Logic 1 Voltage Note 2 1 - 1.3 V Baud = 0 237 250 263 µs Baud = 1 118 125 132 µs Baud = 2 59 62.5 66 µs SDA OUTPUT Synchronization Time TSYNC (Synchronization Pulse Width) NOTE 1: Total System Gain consists of: Wideband System Gain + High and Low Independent Channel Gains + Converter Gain Total System Gain is calibrated during Cal/Config process. NOTE 2: Sample tested. NOTE 3: Volume control is log taper, trimmers are linear taper. ELECTRICAL CHARACTERISTICS (Continued) PARAMETER MIN MAX UNIT ACCURACY Telecoil Gain -8 23 dB type 3 Low Pass compensation Filter 0.5 1 kHz type 1 0.5 4.25 kHz type 1, 2 1 16 kHz type 1, 2 dB/Octave N/A kHz type 1, 2 TELECOIL FREQUENCY SHAPING Crossover Frequency High Cut Filter High Cut Filter Order 6 or 12 Low Cut Filter 0.01 Low Cut Filter Order 3 6, 12 or 18 dB/Octave Equalization Filter Center 0.125 16 kHz Equalization Filter Depth -30 30 dB 0.7079 70.7946 Equalization Filter Q type 1, 2 3 of 14 24501 - 1 GA3216 INPUT ELECTRICAL CHARACTERISTICS (Continued) INDEPENDENT CHANNEL PROCESSING Bandsplit Filter Slopes 6, 12 or 24 dB/Octave type 1, 2 -18 42 dB type 3 High Level Gain -18 42 dB type 3 Lower Threshold 30 110 dBSPL type 3 Upper Threshold 70 110 dBSPL type 3 Compression Ratio 1:1 ∞ :1 Ratio type 3 AGCi Attack Time Constant (Fast & Slow) 0.25 8192 ms type 1, 3 AGCi Release Time Constant (Fast & Slow) 0.25 8192 ms type 1, 3 ratio N/A Squelch Expansion Ratio 1:2 Squelch Threshold 20 60 dBSPL type 3 Squelch Attack Time Constant 0.25 8192 ms type 1, 3 Squelch Release Time Constant 0.25 8192 ms type 1, 3 Wideband System Gain -36 12 dB type 3 Wideband Attack Time Constant (Fast & Slow) 0.25 8192 ms type 1, 3 Wideband Release Time Constant (Fast & Slow) 0.25 8192 ms type 1, 3 External VC -48 0 dB type 3 Internal VC Attenuator -48 0 dB type 3 -19 83 dB Note 1 -30 -1 dBFS* type 3 Ratio N/A WIDEBAND SYSTEM GAIN TOTAL SYSTEM GAIN Total System Gain AGCO AGCo Output Limiting ∞ :1 AGCo Compression Ratio AGCo Attack Time Constant (Fast & Slow) 0.25 8192 ms type 1, 3 AGCo Release Time Constant (Fast & Slow) 0.25 8192 ms type 1, 3 -40 0 dBFS type 3 Pure Tone Frequency (memory and low battery indicator) 0.25 16 kHz type 1, 2 Pure Tone Amplitude (memory and low battery indicator) -50 0 dBFS type 3 PEAK CLIPPER PC Output Limiting TONE GENERATOR * peak output is defined as largest sine wave possible at the resonant frequency of the receiver NOTE 1: Total System Gain consists of Wideband System Gain + High and Low Independent Channel Gains + Converter Gain and accuracy of this parameter is dependent on accuracy of the components. Accuracy definitions: type 1: accuracy is determined by the clock frequency deviation type 2: accuracy is determined by the quantization error of 16bit coefficient and 20bit or higher data word. type 3: accuracy is determined by the quantization error of a parameter word (see table 2 for word length) and 20bit or higher data word. 4 of 14 24501 - 1 GA3216 Low Level Gain VB MS 14 13 SDA 12 VREG2 19 VREG 11 PROGRAMMING INTERFACE 1 EEPROM GA3216 MS2 TONE GENERATOR REGULATOR TWIN DETECTOR IN 3k9 24db/oct BAND SPLIT FILTER 17 1k T 1st to 3rd ORDER LC EQ5 10 HC TWIN DETECTOR T-coil EQ A/D 1st or 2nd ORDER Σ COMPRESSOR HP 16 OUT SQUELCH EQ1 COMPRESSOR EQ4 D/A HBRIDGE PEAK CLIPPING 8 LP FILTER 9 AGC-O EQ2 LP 7 TWIN DETECTOR TWIN DETECTOR SQUELCH MGND 15 VC GAIN EQ3 TRIMMER INTERFACE GA3216 5 2 VC TR1 3 4 20 18 TR2 TR3 6 TR4 Fig. 1 Test Circuit VB MS2 MS To Programming box 14 12 13 19 1 11 PROGRAMMING INTERFACE EEPROM TONE GENERATOR REGULATOR TWIN DETECTOR COMPRESSOR HP 16 A/D Σ TWIN DETECTOR T-coil EQ 24db/oct BAND SPLIT FILTER 17 1st to 3rd ORDER LC 1st or 2nd ORDER SQUELCH EQ1 COMPRESSOR LP EQ5 10 HC EQ4 D/A HBRIDGE PEAK CLIPPING 8 9 AGC-O EQ2 7 TWIN DETECTOR TWIN DETECTOR SQUELCH 15 EQ3 VC GAIN TRIMMER INTERFACE GA3216 2 5 3 4 18 20 6 VC 200k(log) Fig. 2 Example of Programmable Application Circuit 5 of 14 24501 - 1 VB 22 MS 47µ 14 12 13 19 1 11 PROGRAMMING INTERFACE EEPROM TONE GENERATOR GA3216 REGULATOR TWIN DETECTOR A/D Σ COMPRESSOR HP 16 TWIN DETECTOR T-coil EQ 24db/oct BAND SPLIT FILTER 17 1st to 3rd ORDER LC 1st or 2nd ORDER EQ5 10 HC SQUELCH EQ1 COMPRESSOR EQ4 8 D/A HBRIDGE PEAK CLIPPING 9 AGC-O EQ2 LP 7 TWIN DETECTOR TWIN DETECTOR SQUELCH 15 EQ3 VC GAIN TRIMMER INTERFACE GA3216 2 5 VC 3 TR1 4 TR2 20 18 TR3 6 TR4 Fig. 3 Example of Trimmer Application Circuit VB MS 14 12 13 19 1 11 PROGRAMMING INTERFACE EEPROM TONE GENERATOR REGULATOR TWIN DETECTOR COMPRESSOR HP 16 A/D TWIN DETECTOR T-coil EQ 24db/oct BAND SPLIT FILTER 17 1st to 3rd ORDER LC Σ 1st or 2nd ORDER SQUELCH EQ1 COMPRESSOR LP EQ5 10 HC EQ4 D/A HBRIDGE PEAK CLIPPING 8 9 AGC-O EQ2 7 TWIN DETECTOR TWIN DETECTOR SQUELCH 15 EQ3 VC GAIN TRIMMER INTERFACE GA3216 2 5 VC 3 TR1 4 TR2 18 TR3 20 6 TR4 Fig. 4 Application Circuit for Figure 5 6 of 14 24501 - 1 TR1 TR4 TR2 TR3 VC + 2 3 5 6 7 8 16 T-coil 15 GA3216 17 Zero Biased Receiver 9 14 13 12 11 10 + 1 Mic MS switch CS44 Fig. 5 Example of Assembly Diagram For Two-terminal Trimmer Circuit 7 of 14 24501 - 1 60 3 f = 1kHz 55 2.5 50 Fs = 32kHz Fs = 24kHz 40 1.5 GA3216 THD (%) Gain (dB) 2 45 35 1 30 0.5 25 0 20 100 1000 -80 10000 -70 -60 -50 -40 -30 -20 -20 0 Input (dBV) Frequency (Hz) Fig. 9 THD vs Input Level Fig. 6 Frequency Response at 32kHz and 24kHz Sampling Frequency -85 f = 1kHz 0 -90 -20 Output (dBV) Noise (dBV) -95 -100 -105 -40 -60 -110 -115 -80 -120 100 1000 -120 10000 -100 -80 -60 -40 Input (dBV) Frequency (Hz) Fig. 10 Input/Output Curves at Various Gains Fig. 7 Output Noise 2 Vin = -40dBV THD (%) 1.5 1 0.5 0 100 1000 10000 Frequency (Hz) Fig. 8 THD vs Frequency 8 of 14 24501 - 1 INTRODUCTION Configuration data is generated by an ARK product component library (DLL). Like the PARAGON™ Digital products, the GA3216 is fully supported by Gennum's software tools available from the Gennum ARK web site http://ark.gennum.com. During normal trimmer mode operation, a low-speed A/D circuit monitors the positions of up to four manual trimmers and a VC potentiometer. Trimmer position changes are immediately interpreted and translated into new circuit parameter values, which are then used to update the signal path. Gennum's Library Manager tool allows one to predefine trimmer assignments for all common functions such as lowcut, high-cut, notch and resonant-peak-shift filtering, AGC parameters, and maximum power output (MPO). SIGNAL PATH There are two main audio input signal paths. The first path contains the Microphone and second path contains the Telecoil input as selected by a programmable MUX. The microphone input is intended as the main audio input for single-microphone applications. The two audio inputs are buffered, sampled and converted into digital form using an A/D converter. The digital output is then converted into a 32kHz 20-bit digital audio signal. It is possible to save current by reducing the sampling rate to 24kHz, which will also reduce the systems bandwidth from 16kHz to 12kHz. In Telecoil mode, gains are trimmed during the Cal/Config process to compensate for microphone/Telecoil mismatches. The Telecoil input may also be used as a second microphone input. In this case the Telecoil compensation would be disabled. This can be done via the ARKonline wizard. All AGC loops use a feed-forward topology to ensure system stability. Detectors in the AGCi path and AGCo path are twin fast/slow detectors with independently adjustable attack and release time constants. The squelch detector (which resides in the AGCi path) is implemented as a single fast/slow detector. FUNCTIONAL BLOCK DESCRIPTIONS A/D AND D/A CONVERTER The system’s A/D converter is a 2nd-order sigma-delta modulator, which operates at a 2.048MHz sample rate. The system’s input is pre-conditioned with anti-alias filtering and a programmable gain pre-amplifier. The analog output is oversampled and modulated to produce a 1-bit pulse density modulated (PDM) data stream. The digital PDM data is then decimated down to pulse-code modulated (PCM) digital words at the system’s sampling rate of 32kHz. The D/A is comprised of a digital 3rd-order sigma-delta modulator and an H-bridge. The modulator accepts PCM audio data from the DSP path and converts it into a 32times oversampled, 1-bit PDM data stream, which is then supplied to the H-bridge. The H-bridge is a specialized CMOS output driver used to convert the 1-bit data stream into a low-impedance, differential output voltage waveform suitable for driving zero-biased hearing aid receivers. CHANNEL PROCESSING Figure 1 represents the I/O characteristic of independent AGC channel processing. The I/O curve can be divided into four main regions: • low input level expansion (squelch) region • low input level linear region • compression region • high input level linear region (return to linear) 0 High Level Gain -10 OUTPUT LEVEL (dBV) -20 The wideband detector circuit output is routed to a bandsplit filter that divides the signal into two frequency bands. There is an option to configure the hybrid as a single channel device that simply shuts down and bypasses the band-split filter. The signal in each frequency band is processed by an independent AGC loop. The gain in any band is a function of the energy detected in that band or the overall detected wide-band energy. The two frequency bands are then summed back into a wide-band signal. Compression Ratio -30 -40 -50 Upper Threshold Low Level Gain Lower Threshold -60 Squelch Threshold -70 -80 -90 -100 -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 INPUT LEVEL (dBV) Fig. 11 Independent Channel I/O Curve Flexibility 9 of 14 24501 - 1 GA3216 The GA3216 hybrid comprises a configurable two-channel compressor circuit with two methods of operation, programmable mode and trimmer mode. It may be configured as a one or two channel device with linear or WDRC processing. Configuration data stored in non-volatile memory defines hearing-aid parameters. This data needs to be uploaded to the hybrid before the circuit becomes functional. The GA3216 hybrid is programmed via the SDA pin using industry-standard programming boxes. Further processing capabilities include a 1st to 3rd order low cut filter before the band-split filter. After the two channels are summed together there is a 1st or 2nd order high cut filter, three EQ filters followed by volume control, low-distortion AGCo, and two post-AGCo EQ filters. The I/O characteristic of the channel processing can be adjusted in six ways: squelch threshold (SQUELCHTH) • low level gain (LLGAIN) • lower threshold (LTH) • high level gain (HLGAIN) • upper threshold (UTH) • compression ratio (CR) During Parameter Map creation, constraints are applied to the compression parameters to ensure that the I/O characteristics are continuous. In both Programmable mode and Trimmer mode predefined parameter adjustments support two popular styles of compression ratio adjustment: • The compression region of the I/O curve pivots about the upper threshold. As the compression ratio trimmer is adjusted, high-level gain remains constant while the low-level gain changes. • The compression region of the I/O curve pivots about the lower threshold. Low-level gain remains constant as the compression ratio trimmer is adjusted. The two compression channels can be controlled in tandem using a common wideband level detector, or independently using dedicated in-channel level detectors. Parameters such as low level gain, lower threshold and compression ratio can be combined and controlled by a single trimmer. The squelch region within each channel implements a low level noise reduction scheme (1:2 expansion) for listener comfort. This scheme operates in quiet listening environments (programmable threshold) to reduce the gain at very low levels. Single-channel compressor operation is supported by disabling the band split filter and one of the channel compressors. The remaining compressor can be configured as a wide-dynamic-range compressor (WDRC), or as an input compression limiter (ICL). HRX HEAD ROOM EXPANDER The GA3216 has an enhanced Head Room Expander (HRX) circuit, which increases the input dynamic range of the FOUNDATION Digital without any unwanted audible artifacts. This is accomplished by dynamically adjusting the preamplifier’s gain and the post-A/D attenuation depending on the input level. The telecoil input is calibrated during the Cal/Config process. To compensate for the telecoil/microphone frequency response mismatch, a first order filter with 500Hz corner frequency is implemented. Through ARKonline it is possible to implement a telecoil compensation filter with an adjustable corner frequency. To accommodate for the gain mismatch, the telecoil gain is adjusted to match the microphone gain at 500Hz or 1kHz (default) and is selectable in ARKonline. There is also a telecoil gain adjustment parameter, which can be enabled in ARKonline and set in IDS that will allow for manual adjustment of the telecoil gain compensation. VOLUME CONTROL & TRIMMERS All parameters can be controlled via the SDA or assigned to the trimmers. The four trimmers have flexible parameter assignments so any of the four trimmers can be assigned to any available parameters (A complete list of parameters is available on ARKonline). Both the external VC and trimmers can be configured to work with either a two-terminal 200kΩ variable resistor or a three-terminal 0.1MΩ – 1MΩ variable resistor. The volume control may be either linear or log taper, while the trimmers should have a linear taper. In two-terminal configuration the trimmers and VC are connected between GND and the trimmer Input and in three-terminal configuration between GND, Vreg and the trimmer Input. To enable the device to use two terminal trimmers, in IDS under Settings in the Cal/Config menu, click the trimmers tab and select two terminal trimmers. If using two terminal trimmers, they must be calibrated before use. Calibration is not necessary with three terminal trimmer pots. Hysteresis is built into the circuitry to prevent unintentional level toggling. EQUALIZATION FILTERS There are five equalization filters provided on the FOUNDATION Digital for additional frequency shaping. Each EQ filter has three adjustable parameters, centre, depth and Q. One of these parameters can be selected as trimmer adjustable for each filter. For added flexibility it is possible to combine EQ2 and EQ3 or EQ4 and EQ5 together and have them adjusted by one trimmer. AGCo The AGCo module is an output limiting circuit with a fixed compression ratio infinity:1. The limiting level is programmable as a level measured as dB from full scale. 0 dBFS is the maximum output of the device. The AGCo module has its own twin level detector, with programmable attack and release time constants. 10 of 14 24501 - 1 GA3216 • TELECOIL PATH Examples: MS AND MS2 SWITCHES Up to four memories can be configured in programmable mode, or one memory in trimmer mode. Enabled (valid) memories must be sequential. For example, if three memories were required, memories A, B and C would be enabled. Memory A must always be valid. All memory select options are selectable via the ARKonline wizard. If MS2 = OPEN and there are 4 valid memories: ABCABCA… If MS2 = OPEN and there are 3 valid memories: ABABA… If MS2 = HIGH and there are 4 valid memories: D… If MS2 = HIGH and there are 3 valid memories: C… Table 1: Dynamic example with 4 valid memories. T = momentary switch is toggled, 0 = OPEN, 1 = HIGH MS2 0 0 0 1 1 1 0 0 0 1 0 0 0 0 0 0 MS 0 T T 0 T T 0 T T 0 0 T T T T T Memory A B C D D D C A B D B C A B C A In Trimmer mode there is one method for memory select. In this mode, MS (Pin 13) switches the GA3216's input between the microphone and the telecoil using either a momentary or static switch which is selectable using ARKonline. Static Switch on MS and MS2 There are four memory programmable mode: In this mode it is possible to jump from any memory to any other memory simply by changing the state of both switches. If both switches are changed simultaneously then the transition will be smooth, otherwise, if one switch is changed and then the other, the part will transition to an intermediate memory before reaching the final memory. select modes available in Momentary Switch on MS This mode uses a single momentary switch on MS (Pin 13) to change memories. Using this mode will cause the part to start in Memory A and whenever the button is pressed the next valid memory will be loaded. When the user is in the last valid memory, a button press will cause memory A to be loaded. This mode uses two static switches to change memories. The following table describes which memory is selected depending on the state of the switches. The part will start in whatever memory the switches are selecting. If a memory is invalid the part will default to memory A. Examples: MS MS2 Memory If 4 valid memoriesABCDABCDA… If 3 valid memoriesABCABCA… If 2 valid memoriesABABA… If 1 valid memoriesAAA… OPEN OPEN A HIGH OPEN B (if valid otherwise A) OPEN HIGH C (if valid otherwise A) Momentary Switch on MS, Static Switch on MS2 (jump to last memory) HIGH HIGH D (if valid otherwise A) This mode uses a static switch on MS2 (Pin 14) and a momentary switch on MS (Pin 13) to change memories. If the static switch is OPEN, the part will start in memory A and it will behave like momentary with the exception that the last valid memory will not be used. If the static switch on MS2 is set to HIGH, the part will automatically jump to the last valid memory (this will happen on startup or during normal operation). In this setup, the momentary switch's state is ignored. This prevents memory select beeps from occurring. When MS2 is set to OPEN, the part will load in the last select memory. Static Switch on MS, Static Switch on MS2 (jump to last memory) This mode uses two static switches to change memories. Unlike in the previous example, this mode will switch to the last valid memory when the static switch on MS2 is HIGH. This means that this mode will only use a maximum of three memories (even if four valid memories are programmed). The following table describes which memory is selected depending on the state of the switches. 11 of 14 24501 - 1 GA3216 There are two, two-pole Memory Select switches available on the GA3216, which allows the user tremendous flexibility in switching between configurations. These switches may be either momentary or static as set up in ARKonline and are configurable to be either pull-up or pull-down through the setting tab in IDS. In programmable mode the device must be set to pull-down. MS MS2 Memory OPEN OPEN A HIGH OPEN B (if valid otherwise A) OPEN HIGH Last Valid Memory HIGH HIGH Last Valid Memory TONE GENERATOR When MS2 is set HIGH, the state of the switch on MS is ignored. This prevents memory select beeps from occurring when switching MS when MS2 is HIGH. The part will start in whatever memory the switches are selecting. If the device starts up in a memory other than A, and the memory beep tones are enabled, the device will emit the corresponding tones for that memory. If a memory is invalid, the part will default to memory A. AUDIBLE MEMORY CHANGE INDICATOR The FOUNDATION Digital can be configured to produce tones to indicate a memory change. Through ARKonline the GA3216 can be configured to either enable or disable the Memory Change Indicator. When the Memory Change Indicator is enabled, there is an option to have a single beep for each memory change or multiplebeeps. The amplitude and frequency of the memory change tone can be selected independent of the Tone Generator settings and can be individually selected for each memory. When the memory change multiple beep is enabled and the memory change tone is enabled, then during a memory change operation the selected tone will beep a code to indicate which memory has been selected. The beep sequence will be 150ms ON followed by a 150ms OFF time between the beeps. The memory change beeping code is deciphered in the table below. SELECTED MEMORY # OF BEEPS A 1 B 2 C 3 D 4 NOTE: When the sampling frequency is set at 24kHz, the tones will scale. e.g. A 1kHz tone at 32kHz sampling would be approximately 667Hz at 24kHz sampling. LOW BATTERY INDICATOR (POWER-ON/POWER-OFF) During power-on the FOUNDATION Digital is held in a reset state until Vb reaches a turn-on threshold, and the hybrid's internal control logic determines that the supply is stable. When this occurs the hybrid begins its power-on sequence. When a low battery condition (below turn on threshold) is detected, the FOUNDATION Digital sends out a series of 3 beeps (225ms ON, 225ms OFF, 225ms ON, 225ms OFF, 225ms ON) to indicate the battery is low. This will repeat every 5 minutes until the device reaches the turn-off threshold. If Vb drops below the turn-off threshold then the FOUNDATION Digital is returned to its reset state and the audio output is muted. There are four reset modes which are selectable through ARKonline. The first is the shallow-reset mode which, during the powerON sequence circuit starts when the supply voltage rises above the turn-ON threshold after shutdown. The device will function until the supply voltage drops below the turn-OFF threshold but will recover when the device rises above the turn-ON threshold again. The second is deep-reset mode which begins when the supply voltage rises above the turn-ON threshold after shutdown. Once the supply voltage drops below the turnOFF threshold the GA3216 will shut down and remain there until the supply voltage drops below approximately 0.3V and subsequently rises above the turn-ON threshold after shutdown. The third is a combination of these two modes, where the device starts up in shallow-reset mode initially, then changes over to deep reset mode after 5 minutes. 12 of 14 24501 - 1 GA3216 In this mode it is possible to jump from any memory to any other memory simply by changing the state of both switches. If both switches are changed simultaneously then the transition will be smooth, otherwise, if one switch is changed and then the other, the part will transition to an intermediate memory before reaching the final memory. The tone generator is capable of producing programmable tones. When the Tone Generator is enabled, the FOUNDATION Digital connects the output of the tone generator to the input of the D/A converter. The programmed tone is the output until the Tone Generator is disabled. When disabled, the normal audio signal path is again connected. The tone generator will produce a beep to indicate a memory select change, a microphone/telecoil selection change or to warn the user of low battery voltage. CURRENT CONSUMPTION Typical current consumption of the FOUNDATION Digital, as stated in the Electrical Characteristics section, is measured at a specific configuration and settings. If lower current is desired, it can be achieved by selecting a 24kHz sampling rate from the settings tab in IDS. This will reduce the systems bandwidth from 16kHz to 12kHz. For the FOUNDATION Digital device settings used when measuring system current, please refer to the "current_configuration.ids" file at: www.gennum.com/hip/parts/ga3216.htm. POWER MANAGEMENT The FOUNDATION Digital was designed to accommodate high power applications. AC ripple on the supply can cause instantaneous reduction of the battery's voltage, potentially disruption the circuit's function. The GA3216 has a separate power supply and ground connection for the output stage. This allows hearing instrument designers to accommodate external RC filters in order to minimize any AC ripple from the supply line. Reducing this AC ripple greatly improves the stability of the circuit and prevents unwanted reset of the circuit caused by spikes on the supply line. For more information on properly designing a filter to reduce supply ripple, please refer to information note "Using the GB3211 PARAGON Digital in High Power Application Initial Design Tips" document #24561. SOFTWARE Full software support is provided for every stage of development from design to manufacturing to fitting. Please refer to the “Getting Started with ARK Guide,” document # 27217. SDA COMMUNICATION The FOUNDATION Digital is programmed via the SDA pin using industry standard programming boxes. During parameter changes the main audio signal path of the hybrid is temporarily disable and replaced with a low gain "bypass path" to avoid the generation of disturbing audio transients. Once the changes are complete, the main audio path is reactivated. Any changes made during programming will be lost at power-off unless they are explicitly burned to EEPROM memory. 13 of 14 24501 - 1 GA3216 The fourth option is to have the gain reduced as the battery voltage drops. When the supply falls below the low battery threshold the low battery tones will be emitted and the wideband gain will be reduced by 3dB. As the battery voltage continues to drop, the low battery tones will continue and the wideband gain will continue to be reduced until the turn-OFF threshold is reached when the device will shut down. PACKAGE DIMENSIONS PAD LOCATIONS 0.065 MAX (1.60) 0.165 (.419) 0.0185 (.470) 1 2 3 4 5 6 17 8 20 19 18 16 15 7 9 14 13 12 11 10 Dimension units are in inches. Dimensions in parentheses are in millimetres, converted from inches and include minor rounding errors. 1.0000 inches = 25.400mm Dimension tolerances: ±0.005 (±0.13) unless otherwise stated. Work order number: XXXXXX This Hybrid is designed for either point-to-point manual soldering or for reflow according to Gennum's reflow process (Information Note 521-45). PAD DIMENSIONS Y Xdim Ydim 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 0 27 53 79 105 131 157.5 154 154 154 122 92.5 63.5 34.5 3 3 3 39.5 78.5 117.5 0 -1.75 -1.75 -1.75 -1.75 -1.75 -1.75 -34.25 -62.25 -88.75 -84.25 -84.25 -84.25 -84.25 -86.5 -57.25 -29.75 -45.25 -45.25 -45.25 20 18 18 18 18 18 19 26 26 26 22 21 21 21 26 26 26 31 31 31 24 27.5 27.5 27.5 27.5 27.5 27.5 21.5 18.5 18.5 27.5 27.5 27.5 27.5 23 19.5 19.5 20.5 20.5 20.5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 0 0.686 1.346 2.007 2.667 3.327 4.001 3.912 3.912 3.912 3.099 2.350 1.613 0.876 0.076 0.076 0.076 1.003 1.994 2.985 0 -0.044 -0.044 -0.044 -0.044 -0.044 -0.044 -0.870 -1.581 -2.254 -2.140 -2.140 -2.140 -2.140 -2.197 -1.454 -0.756 -1.149 -1.149 -1.149 0.508 0.457 0.457 0.457 0.457 0.457 0.483 0.660 0.660 0.660 0.559 0.533 0.533 0.533 0.660 0.660 0.660 0.787 0.787 0.787 0.610 0.699 0.699 0.699 0.699 0.699 0.699 0.546 0.470 0.470 0.699 0.699 0.699 0.699 0.584 0.495 0.495 0.521 0.521 0.521 MIL X GA3216 GA3216 0.123 (3.12) PAD POSITION mm PAD NO. 0.190 (4.82) DOCUMENT IDENTIFICATION REVISION NOTES: PRELIMINARY DATA SHEET The product is in production. Gennum reserves the right to make changes at any time to improve reliability, function or design, in order to provide the best product possible. Update to data sheet. Add min/max. Add IO curves. Edit descriptions. Add moisture sensitivity information. Update specs for Programmable version. GENNUM CORPORATION GENNUM JAPAN CORPORATION MAILING ADDRESS: P.O. Box 489, Stn A, Burlington Ontario, Canada L7R 3Y3 Tel. +1 (905) 632-2996 fax: +1 (905) 632-2814 Shinjuku Green Tower Building 27F, 6-14-1, Nishi Shinjuku, Shinjuku-ku, Tokyo, 160-0023 Japan Tel. +81 (03) 3349-5501, Fax. +81 (03) 3349-5505 SHIPPING ADDRESS: 970 Fraser Drive, Burlington, Ontario, Canada L7L 5P5 Gennum Corporation assumes no responsibility for the use of any circuits described herein and makes no representations that they are free from patent infringement. © Copyright October 2002 Gennum Corporation. All rights reserved. Printed in Canada. 14 of 14 24501 - 1