Data Sheet
PT8A977P/977W/978P/978LW
5-Function Remote Controller
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Features
General Description
• PT8A977P/977W works as encoder and
PT8A978P/978LW works as decoder
• Five pins for five control functions
• 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
• Press on any button as wake up (977P, 977W)
• Manual-power-off with OFF button
• One output pin used for external power control (977P,
977W)
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.
• On-chip oscillator with an external resistor
• On-chip reversing amplifiers (978P, 978LW)
• Low operating current
• Few external components needed
• Package: 14-pin DIP, 14-pin SOIC, 16-pin DIP
and 16-pin SOIC
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%.
Ordering Information
Part No.
PT8A977P
PT8A977W
PT8A978P
PT8A978LW
Package
14-pin DIP
14-pin SOIC
16-pin DIP
16-pin SOIC
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.
PT0074(10/01)
Ver:1
1
PERICOM [ PERICOM SEMICONDUCTOR CORPORATION ]
