EM91401CP

Manufacturer Part NumberEM91401CP
DescriptionTone/pulse switchable dialer with LCD interface and dual tone melody generator
ManufacturerELAN Microelectronics Corp
EM91401CP datasheet
 


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PIN DESCRIPTIONS

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FUNCTIONAL BLOCK DIAGRAM
COL1
Keyboard
COL2
COL3
interface
COL4/KT
(column)
COL5
XIN
Oscillator
XOUT
ROW1
Keyboard
ROW2
interface
ROW3
(Row)
ROW4

PIN DESCRIPTIONS

Symbol
ROW1~ROW4
Keyboard scan pins of row group. In idle state (HKS is “High” and HFO is “Low”),
these pins stay “High impedance” level to prevent power consumption. Otherwise,
these pins switch to “High” level for detecting keyboard entry. These pins will output
600 Hz signal while keyboard is scanning.
COL1~COL3
Keyboard scan pins of column group. In idle state, these pins stay “High impedance”
level. Otherwise these pins switch to “Low” level for detecting keyboard entry. These
pins will output 600 Hz signal while keyboard is scanning.
COL4/KT
The fourth column group pin of the keyboard that also provides the keytone output
. Normally, this pin stays “Low” level for detecting keyboard entry. After a valid
keyboard entry, this pin will output keying confirmation tone that is 600 Hz signal and
30 ms duration. To prevent signal interference, while DTMF issue, it will disable key
tone output except function key.
XIN and XOUT
Oscillator input and output pins. A 3.579545 MHz crystal or ceramic resonator must
be crossed connection to XIN and XOUT pins which generate system clock.
XMUTE
The Tone/Pulse MUTE signal output pin that is NMOS open-drain output structure.
This pin will switch to “Low” level during Tone/Pulse dialing and hold function .
Otherwise, this pin stays “High impedance” level.
V
and V
Positive and negative power supply input pins. Recommended operating voltage from
DD
SS
2.0Vdc to 5.5Vdc.
HFI
Handfree inputs pin which accepts falling edge signal to turn “on” or turn “off”
handfree function. This pin is hysteresis input structure and built-in pull up resistor
(typically 200 Kohms).
HFO
Handfree outputs pin that is designed to control telephone line for on-hook dialing or
control speakerphone circuit for handfree conversation. When handfree function is
executed, this pin will switch to“High”. Otherwise, this pin stays “Low” level.
DTMF
The DTMF (Dual Tone Multi-Frequency) and music signals output pin. Normally,
this pin stays “Low” level. In Tone dialing mode, this pin will output DTMF signal
that is corresponding to keyboard 0 .. 9, * and # keys. Beside this, in the line hold
duration, this pin will issue dual-tone music for telephone line.
* This specification are subject to be changed without notice.
TONE/PULSE SWITCHABLE DIALER WITH LCD INTERFACE
AND DUAL-TONE MELODY GENERATOR
RMUTE
HFO HDO
SDO
XMUTE
Row/Column
Output circuit
programming counter
latch
Memory
&
(Melody)
decoder
Timing/Control circuit
Pulse
generator
Input circuit
VDD
VDD
HFI
HKS
DRING
Function
EM91401 SERIES
D/A
DTMF
converter
PO
10.1.1997
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