IC DESCRIPTION
IC, TC9297F
Pin No.Pin NameI/oDescription
Key scan inputs.A maximumof 6x5=30 key data can be input with a matrix of key
1-4K1 - K4Iscan outputs TO - T5. When?H? isapplied to thispin,scanning of keys willstart.
These pins incorporate pull-down resistors.
Key scan timing outputs.Since a load resistorRONisbuiltintothe N-ch to form a key
5-1oTO - T5omatrix, a diode isnot necessary. In normal operation,these pins output ?H?, and when
?H? isapplied to key scan inputsKO - K4, key scanning willstart.
11COM1oLCDcommonsignaloutputs.When1/2duty isset,matrixing of COM1,2 and
12COM2oSO - S39 rdlows the display of up to 80 segments. When1/3 duty isset,matrixing of
COM1-3and S 1- S39 allows display of up to 117 segments.In the 1/3 duty mode, the
13SO/COM3o
SO pin isused as a COM3pin.
LCDsegment signaloutputs.When1/2 duty isset,matrixing of COM1,2 and
14-48S1-S35o
SO - S39 allows display of up to 80 segments. When1/3 duty isset,matrixing of
COM1-3and S 1- S39 allows display of up to 117 segments. S36 - S39 are commonly
49-52S3610T3- S3910T0oused forLED drivers.The LED driveroutputs become N-ch open drain outputs,and
the LEDs can be directlyindicatedsince they are driven by high current.
53GNDGND
C and R which are attached externallyform an oscillator.
The oscillationfrequency isshown by the following formula
54Osc?fosc = 1.5/(C .R)[Hz]
For example, when C = 0.01 p F and R = 30 k Q ,
fosc = 5 kHz.
Power supply input.Normally, a voltage VRST-5.5 V isapplied.This pin isprovided
55VDD?with a power-on resetfunction:the system resetwillfunction when power isturned on
or VDDislessthan 3 V (standard).
Device system resetsignalinput.WhenRST input is?L?, the oscillatorwillstop,all
internaldata willbe resetand the LCDoutput pins and key scan output pins willbe
56RSTI
fixed at ?H?. For normal operation,connect thispinto VDD,since the device
incorporatesa power-on resetcircuit.
Serialinterfacepins.The device communicatesthe display data,key input data and the
57CKI
data which controlsthese with the controller.Whenthe CE pin is?L?, data willnot be
communicated. Whenitgoes ?H?, data willbe communicatedbetween the DATApin
58DATAIlo
and controller,synchronized with the clock signalinput to the CK input pin.All these
59CEIpins have Schmitt input circuits.
Key scan input.A maximumof 6x5=30 key data can be input with a matrix of key
60KOIscan outputs TO - T5. When?H? isapplied to thispin,scanning of keys willstart.This
pin incorporates a pull-down resistor.
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