ACO160
Deluxe Audio-Controlled Oscillator
3
999 SW 1
st
Ave. #1617, Miami, FL 33130
Pin
Name
Direction
Description
15
SIN
Output 0-VDDA Sine wave output level-shifted up by about 1v.
16
SINFILT
In/Out
0-VDDA Filter node for sine wave, bypass this pin to ground with a
100pF capacitor close to the chip
17
VSS
Supply
Ground
18
AHARM
Input
Harmony CV input: 0v = -2 octaves; VDDA = +2 octaves; in between,
tunes to the nearest semitone on the chromatic equal-tempered scale
19
VSS
Supply
Ground
20 FLL/SCLK
Output 0-VDDA: In MIDI mode (MODE1 = 1), SPI clock (SCLK)
In synchronous sample clock mode (MODE1/0 = 00), ACO output
divided down by the appropriate power of two to give a sample
frequency roughly between 100kHz and 200kHz
In analog-only synth mode (MODE1/0 = 01), quiet
21 DOWN/N
SS
Output 0-VDDA: In MIDI mode (MODE1 = 1), SPI active-low enable (NSS)
In synchronous sample clock mode (MODE1/0 = 00), single pulse over
one cycle of FLL output when the sample frequency drops by 2x
In analog-only synth mode (MODE1/0 = 01), quiet
22 UP/MOSI Output 0-VDDA: In MIDI mode (MODE1 = 1), SPI master out slave in (MOSI)
In synchronous sample clock mode (MODE1/0 = 00), single pulse over
one cycle of FLL output when the sample frequency increases by 2x
In analog-only synth mode (MODE1/0 = 01), CK1024 clock running
1024x the input signal frequency (for external SC filters)
23
VDDD
Supply
3.3v digital supply, bypass with 1.0-2.2uF ceramic capacitor and
connect to VDDA on the PCB
24
VSS
Supply
Ground
25
ARATE
Input
Analog input for envelope follower rate control:
0v-VDDH/8: envelope decays to 32% of its initial value in one cycle
VDDH/8-2*VDDH/8: envelope decays to 45% of its value in one cycle
2*VDDH/8-3*VDDH/8: envelope decays to 56% of its value in one cycle
3*VDDH/8-4*VDDH/8: envelope decays to 67% of its value in one cycle
4*VDDH/8-5*VDDH/8: envelope decays to 75% of its value in one cycle
5*VDDH/8-6*VDDH/8: envelope decays to 82% of its value in one cycle
6*VDDH/8-7*VDDH/8: envelope decays to 86% of its value in one cycle
7*VDDH/8-VDDH: envelope decays to 90% of its value in one cycle
26
ACINN
Input
0-VDDH negative polarity audio input
27
ACINP
Input
0-VDDH positive polarity audio input
28 THRESH
Input
0-VDDA analog gate threshold input
29
ENV
Output 0-VDDH analog envelope follower output
30
GATE
Output Gate output; When ENV output exceeds THRESH voltage, Gate = VDDH;
When ENV output is below THRESH voltage, GATE = 0v. Internal
hysteresis is included to avoid double toggling when GATE changes
state.
31
VSS
Supply
Ground
32
VDDH
Supply
4.5-5.5v I/O supply
