Data Sheet

PT8A977P/977W/978P/978LW

5-Function Remote Controller

PT0074(10/01)

Ver:1

1

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Features

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PT8A977P/977W works as encoder and

PT8A978P/978LW works as decoder

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Five pins for five control functions

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Operating power-supply voltage: 2.5V to 5.0V

(977P, 977W, 978P), 2.0V to 5.0V (978LW)

•

Auto-power-off if no press on any button in 8s or

continuously press on any button over 4 minues

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Press on any button as wake up (977P, 977W)

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Manual-power-off with OFF button

•

One output pin used for external power control (977P,

977W)

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On-chip oscillator with an external resistor

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On-chip reversing amplifiers (978P, 978LW)

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Low operating current

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Few external components needed

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Package: 14-pin DIP, 14-pin SOIC, 16-pin DIP

and 16-pin SOIC

General Description

The PTA977P (or 977W) and PT8A978P (or 978LW)

provide a complete control functions to the remote-

controlled toy. The PT8A977P/977W has five input

pins corresponding with the five function buttons i.e,

forward, backward, rightward, leftward and turbo. The

encoding circuit in the PT8A977P/977W 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 PT8A978P (or 978LW) 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.

There is an internal oscillator in the PT8A977P/977W

and 978P/978LW 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

PT8A977P/977W and PT8A978P/978LW must be

less than ±25%.

The auto-power-off function is achieved by an internal

counter. The PC output is used to control on/off state

of the external power supply. Pressing OFF button

can also shut down the power supply. Press on any

function button will wake up the chip promptly.

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Ordering Information