HT8950_06 Datasheet, PDF (1/10 Pages) Holtek Semiconductor Inc – Voice Modulator

HT8950/HT8950A
Voice Modulator
Features
· Operating voltage: 2.4V~4.0V
· On-chip SRAM
· Robot function
· Vibrato function
· 8kHz sampling rate
· 7-step level shifting
· 8-bit A/D and D/A converters
· LED indicator with voice level
· Push button selection or electronic mode
· Minimal external components
· HT8950: 18-pin DIP package
HT8950A: 16-pin DIP package
Applications
· Educational Toys/leisure products
· Mixers
· Recorders
· Audio system
· Speech system
· Telephone system
General Description
The HT8950/HT8950A are single chip CMOS LSI voice
modulator ICs which provide seven steps to shift the fre-
quency of an input voice, producing a dramatic change
in the output.
The HT8950/HT8950A provide two special effects: Vi-
brato and Robot. The Vibrato effect is generated by al-
ternating the frequency of an input signal up and down
at a rate of 8Hz. The Robot function, on the other hand,
converts an input voice into a Robot voice. Both effects
can be selected depending on which pin is triggered, ei-
ther ROB or VIB. For the output frequency level shifting,
the chips provide seven steps which can be selected
Pin Assignment
from the two groups of pins namely, SW0, SW1 and
SW2 for electronic direct selection and ROB, TGD, TGU
and VIB for push button selection.
The HT8950/HT8950A include a built-in microphone
amplifier with an internal bias, an 8-bit A/D converter, a
built-in SRAM as well as a current output type 8-bit D/A
converter. The 8-bit A/D and D/A converters with a sam-
pling rate of 8kHz ensures a high quality and high S/N
ratio output voice. The chips provide an LED indicator
which flashes in accordance with the volume of the input
voices.
SW 0
SW 1
SW 2
VSS
AO
A IN
VDD
LA M P
A U D IO
1
18
2
17
3
16
4
15
5
14
6
13
7
12
8
11
9
10
H T8950
1 8 D IP -A
ROB
TG D
TG U
V IB
O SC1
O SC2
F V IB
TS
VREF
O SC1
V IB
TG U
TG D
ROB
VSS
NC
AO
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
H T8950A
1 6 D IP -A
O SC2
F V IB
TS
VREF
A U D IO
LA M P
VDD
A IN
Rev. 1.10
1
November 16, 2006