Data Sheet
PT8A977B/978B/978BL
5-Function Remote Controller
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Features
• PT8A977B works as encoder and PT8A978B/
978BL works as decoder
• Five pins for five control functions
• Operating power-supply voltage: 2.5V to 5.0V (978B),
2.0V to 5.0V (978BL), 1.8V to 5.0V(977B)
• Auto-power-off and oscillation-off if no press on
any button (977B)
• Press on any button to wake up (977B)
• One output pin used for external power control
(977B)
• On-chip oscillator with an external resistor
• On-chip reversing amplifiers (978B, 978BL)
• Low operating current
• Few external components needed
• Package: 14-pin DIP, 14-pin SOIC, 16-pin DIP
and 16-pin SOIC
General Description
The PT8A977B and PT8A978B (or 978BL) provide
complete control functions to the remote-controlled
toy. The PT8A977B has five input pins corresponding
with the five function buttons i.e, forward, backward,
rightward, leftward and turbo. The encoding circuit
in the PT8A977B sends digital codes to the two output
pins SO and SC. The digital codes correspond to the
definite function buttons or their combinations. The
SO and SC outputs are used in wireless and infra-red
applications respectively.
The PT8A978B (or 978BL) has five output pins
corresponding with the five actions. The received
signals are amplified by the three-stage amplifier, and
then the appropriate amplified signals are sampled,
fault-tolerantly checked and decoded to control the
actions of the remote-controlled toy.
Ordering Information
Part No.
PT8A977BP
PT8A977BW
PT8A977BDE
PT8A978BP
PT8A978BLW
PT8A978BDE
Package
14-pin DIP
14-pin SOIC
Die Form
16-pin DIP
16-pin SOIC
Die Form
There is an internal oscillator in the PT8A977B and
978B/978BL respectively. By adding an external
resistor conveniently, the oscillator will be
constructed. The oscillator frequency can be adjusted
by the external resistor. The relative error between
the frequencies of the two on-chip oscillators in the
PT8A977B and PT8A978B/978BL must be less than
±25%.
The auto-power-off function is achieved by an internal
counter (977B). The PC output is used to control on/
off state of the external power supply. Press on any
function button will wake up the chip promptly.
PT0085(02/04)
1
Ver:5
Data Sheet
PT8A977B/978B/978BL
5-Function Remote Controller
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Pin/Pad Description
Pin/Pad Description of 977B
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Pin/Pad Name
Right
Test
GND
Backward
Forward
Turbo
SC
SO
V
cc
PC
OSCO
OSCI
OFF
Left
Description
With Pull-up resistor, rightward function selected if this pin connected to GND.
With Pull-up resistor, this pin is used for testing mode.
Negative power supply
With Pull-up resistor, backward function selected if this pin connected to GND.
With Pull-up resistor, forward function selected if this pin connected to GND.
With Pull-up resistor, turbo function selected if this pin connected to GND.
Output pin of the encoding signal with carrier frequency
Output pin of the encoding signal without carrier frequency
Positive power supply
Power control output pin
Oscillator output pin
Oscillator input pin
With Pull-up resistor, this pin is used to shut down the external power supply.
With Pull-up resistor, leftward function selected if this pin connected to GND.
Pin/Pad Description of 978B/978BL
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Pin/Pad Name
VO2
GND
SI
OSCI
OSCO
Right
Left
RD
LD
Backward
Forward
Turbo
V
cc
VI1
VO1
VI2
Description
Output pin for the amplifier 2
Negative power supply
Input pin of the encoding signal
Oscillator input pin
Oscillator output pin
Rightward output pin
Leftward output pin
With Pull-up resistor, rightward function disabled if this pin connected to GND.
With Pull-up resistor, leftward function disabled if this pin connected to GND.
Backward output pin
Forward output pin
Turbo output pin
Positive power supply
Input pin for the amplifier 1
Output pin for the amplifier 1
Input pin for the amplifier 2
PT0085(02/04)
5
Ver:5
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