ETC GA3216

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]
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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
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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
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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.
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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
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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
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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
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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
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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
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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.
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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.
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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.
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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.
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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.
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