Programmable
Single-/Dual-/Triple- Tone Gong
Preliminary Data
SAE 800
Bipolar IC
Features
q
q
q
q
q
q
q
q
q
Supply voltage range 2.8 V to 18 V
Few external components (no electrolytic capacitor)
1 tone, 2 tones, 3 tones programmable
Loudness control
Typical standby current 1
µA
Constant current output stage (no oscillation)
High-efficiency power stage
Short-circuit protection
Thermal shutdown
P-DIP-8-4
P-DSO-8-1
Type
w
SAE 800
w
SAE 800 G
w
New type
Ordering Code
Q67000-A8339
Q67000-A8340
Package
P-DIP-8-4
P-DSO-8-1 (SMD)
Functional Description
The SAE 800 is a single-tone, dual-tone or triple-tone gong IC designed for a very wide supply
voltage range. If the oscillator is set to
f
0
= 13.2 kHz for example, the IC will issue in
triple-tone-
mode
the minor and major third e
2
– C sharp – a, corresponding to 660 Hz – 550 Hz – 440 Hz, in
dual-tone-mode
the minor third e
2
– C sharp, and in
single-tone-mode
the tone e
2
(derived from
the fundamental frequency
f
0
;
f
1
=
f
0
/ 20,
f
2
=
f
0
/ 24,
f
3
=
f
0
/ 30).
When it is not triggered, the IC is in a standby state and only draws a few
µA.
It comes in a compact
P-DIP-8-1 or P-DSO-8-1 (SMD) package and only requires a few external components.
Semiconductor Group
1
09.94
SAE 800
SAE 800
SAE 800 G
Pin Configuration
(top view)
Pin Definitions and Functions
Pin
1
2
3
4
5
6
7
8
Symbol
GND
Q
Function
Ground
Output
Supply Voltage
Loudness Control
Oscillator Resistor
Oscillator Capacitor
Trigger 2 (dual tone)
Trigger 1 (single tone)
V
S
L
R
OSC
C
OSC
E2
E1
Functional Description
(cont’d)
An RC combination is needed to generate the fundamental frequency (pin
R
OSC
,
C
OSC
). The volume
can be adjusted with another resistor (pin L). The loudspeaker must be connected directly between
the output Q and the power supply
V
S
. The current-sink principle combined with an integrated
thermal shutdown (with hysteresis) makes the IC overload-protected and shortcircuit-protected.
There are two trigger pins (E1, E2) for setting single-tone, dual-tone or triple-tone mode.
Semiconductor Group
2
SAE 800
Block Diagram
Semiconductor Group
3
SAE 800
Circuit Description
Trigger
Positive pulses on inputs E1 and/or E2 trigger the IC. The hold feedback in the logic has a delay of
several milliseconds. After this delay has elapsed, the tone sequence is started. This prevents
parasitic spikes from producing any effect on the trigger pins.
The following
table
shows the trigger options:
E1
Triggered
Grounded/open
Triggered
Oscillator
This is a precision triangle oscillator with an external time constant (R x C). Capacitor
C
C
on pin
C
OSC
is charged by constant current to 1 V and then discharged to 0.5 V. The constant current is obtained
on pin
R
OSC
with an external resistor
R
R
to ground.
When the voltage on
C
OSC
is building up, the logic is reset at 350 mV. This always ensures that a
complete tone sequence is issued. If the oscillator pin is short-circuited to GND during operation,
the sequence is repeated.
E2
Triggered
Triggered
Grounded/open
Mode
Triple-tone
Dual-tone
Single-tone
Issued Sequence
Minor and major third
Minor third
1st tone of minor third
The following applies:
∆V
C
x
C
C
=
I
C
x T/2 with
I
C
=
V
R
/2
R
R
= 1.2 V/2
R
R
f
0
= 5/8 x 1/(
R
R
x
C
C
)
Voltages on Pin
C
OSC
Semiconductor Group
4
SAE 800
Logic
The logic unit contains the complete sequence control. The oscillator produces the power-on reset
and the clock frequency. Single-tone, dual-tone or triple-tone operation is programmed on inputs
E1 and E2. The 4-bit digital/analog converters are driven in parallel. In the event of oscillator
disturbance, and after the sequence, the dominant stop output is set. By applying current to pin L,
the sequence can be shortened by a factor of 30 for test purposes.
The following figure shows the envelope of the triple-tone sequence:
Envelope of maximum amplitudes of three
superimposed tones on Q (time scale for
f
OSC
= 13.2 kHz)
Ratio of maximum amplitudes
M3 : M2 : M1 = 1 : 0.89 : 0.67
Envelope of the Triple-Tone Sequence
Semiconductor Group
5
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