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HT8950 Voice Modulator
Features
* * * * * *
Operating voltage: 2.4~4.0V 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 Few external components required 16-pin/18-pin DIP package
Applications
* * *
Toys Mixers Recorders
* * *
Audio system Speech system Telephone system
General Description
The HT8950 is a single chip CMOS LSI voice modulator. It provides 7 steps to shift the frequency of an input voice, producing a dramatical change in the output. The HT8950 provides two special effects: Vibrato and Robot. The Vibrato effect is generated by alternating 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, either ROB or VIB. For the output frequency level shifting, the chip provides 7 steps which can be selected 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 includes 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 sampling rate of 8kHz ensures a high quality and high S/N ratio output voice. The chip provides an LED indicator which flashes with the volume of the input voices. It is offered in a 16-pin or 18-pin DIP package.
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HT8950
Pin Assignment
Block Diagram
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HT8950
Pad Coordinates
Pad No.
1 2 3 4 5 6 7 8 9 Unit: m
X
-957.0 -957.0 -957.0 -957.0 -957.0 -957.0 -962.0 -161.5 200.5
Y
720.5 423.5 210.0 -87.0 -299.5 -596.5 -815.0 -747.5 -747.5
Pad No.
10 11 12 13 14 15 16 17 18
X
732.0 984.0 956.5 956.5 956.5 530.5 345.50 -33.50 -287.50
Y
-774.0 -675.0 -400.0 374.5 671.5 765.5 765.5 765.5 765.5
Chip size: 2350 x 2080 (m)2
The IC substrate should be connected to VSS in the PCB layout artwork.
Pin Description (18 Pin Version)
Pin No.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Pin Name I/O
SW0 SW1 SW2 VSS AO AIN VDD LAMP AUDIO Vref TS Fvib OSC2 OSC1 VIB I I I I O I O O O I I O O I I
Internal Connection
Pull-High Pull-High Pull-High -- -- -- --
Description
Function setting pin (for electronic setting) Function setting pin (for electronic setting) Function setting pin (for electronic setting) Negative power supply (GND) Internal amplifier output Internal amplifier input (inverted) Positive power supply
NMOS Lamp output (brightness changes with voice volume) Open Drain PMOS Audio output Open Drain -- -- -- -- -- Pull-High Internal amplifier reference voltage For IC test only Vibrato frequency control Oscillator output Oscillator input Switch to Vibrato mode (toggle)
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Pin No.
16 17 18
Pin Name I/O
TGU TGD ROB I I I
Internal Connection
Pull-High Pull-High Pull-High
Description
Switch to Upward step mode Switch to Downward step mode (internal pull-high) Switch to Robot mode (internal pull-high)
Absolute Maximum Ratings*
Supply Voltage ................................. -0.3V to 6V Input Voltage................. VSS-0.3V to VDD+0.3V Storage Temperature................. -50C to 125C Operating Temperature............... -20C to 70C
*Note: These are stress ratings only. Stresses exceeding the range specified under "Absolute Maximum Ratings" may cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability.
Electrical Characteristics
Symbol
VDD IOP VIN ILAMP AV IO VIH VIL fOSC
(Ta=25C)
Parameter
Operating Voltage Operating Current Input Signal Lamp Sink Current OPA Gain Value Audio Output Voltage "H" Input Voltage "L" Input Voltage Oscillating Frequency
Test Conditions VDD
-- 3V 3V 3V 3V 3V -- -- 3V
Min.
2.4 -- -- 5.0 -- -- 0.7VDD -- --
Typ.
3.0 2.0 -- 9.5 2000 -1.0 -- -- 512
Max.
4.0 10 580 -- -- -- -- 0.3VDD --
Unit
V mA mV mA
Conditions
-- No load, fOSC=640kHz -- VOL=1.3V Open loop During silence -- -- ROSC=47k
mA V V kHz
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HT8950
Functional Description
The HT8950 is a single chip LSI designed for voice modulation. It provides 7 steps to shift the frequency of an input voice signal up and down. The chip is also equipped with two special effects; Vibrato and Robot. The HT8950 includes a built-in amplifier, 8-bit A/D converter and current output type of 8-bit D/A converter in addition to a built-in SRAM. The brightness of an LED indicator changes with the volume of the input voice signal.
Power on initial
the frequency of an input signal. The voice modulation is selected and determined by the SW0~SW2 inputs.
Input SW2 SW1 SW0
1 1 1 1 0 0 0 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 1 0
Step Mode
Speed Ratio
Controlled by TGU Notes and TDG UP3 UP2 UP1 NORMAL DN1 DN2 DN3 2 8/5 4/3 1 8/9 4/5 2/3
The HT8950 enters the Robot state right after power is initially switched on.
Robot state
The system goes into the Robot state after the ROB pin is triggered or power is turned on. In this mode, an input voice can be converted into a robot voice.
Vibrato
Notes: The TGU switch elevates by one step mode, and the TGD switch, on the other hand, falls one step mode step by step as shown:
* The system changes to the Robot state after
An output voice will be generated with a vibrato effect when the VIB pin is triggered, regardless of what state the system is in. The vibrato effect is toggle activated. In other words, when a voice output is playing with a vibrato effect, this effect can be eliminated by retriggering the VIB pin. The rate of vibrato effect can be changed by adjusting the resistance of the external resistor between the OSC2 and Fvil pins.
Voice modulation
the ROB pin is triggered, regardless of what state the system is in.
* A voice output is accompanied with a vibrato
effect after the VIB pin is triggered, regardless of what state the system is in.
LED indicator
The HT8950 provides an 8-bit A/D and a D/A converters with a sampling rate of 8kHz, ensuring a voice output of high quality and with a high S/N ratio. The chip includes 7 steps to shift
The HT8950 provides a LAMP pin to drive an external LED. The brightness of LED changes with the volume of the input voice signal.
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HT8950
Application Circuits
16-pin version with an LM386 power amplifier and a 6V power supply
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HT8950
18-pin version with an LM386 power amplifier and a 6V power supply
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HT8950
16-pin version with a transistor output stage and a 6V power supply
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HT8950
18-pin version with a transistor output stage and a 6V power supply
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HT8950
16-pin version with a TDA2822 power amplifier and a 6V power supply
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HT8950
18-pin version with a TDA2822 power amplifier and a 6V power supply
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