EM91865A EMC [ELAN Microelectronics Corp], EM91865A Datasheet - Page 2

• Manufacturer Part Number: EM91865A
• Description: 13 MEMORY TONE/PULSE DIALER WITH HF, HD, REDIAL AND VOLUME CONTROL FUNCTION
• Manufacturer: EMC [ELAN Microelectronics Corp]

PIN ASSIGNMENTS
PIN DESCRIPTIONS
* This specification are subject to be changed without notice.
K2 , K3 , K5 ~ K8
I/O pin
K1/HDO
K4/MuteO
K6/XMUTE
VDD, VSS
Xin, Xout
HFI
HFO
HKS
DTMF
PO
VAO
Symbol
K6/XMUTE
K4/MUTEO
Key board scan I/O pins, key scans by ripple way.
Positive and negative power supply input pin
Oscillator input and output pins, built in two 5pf capacitor so it's not need external capacitor.
These pins output 16K Hz signal one by one and periodically for key board scan.
This pin has two functions
Normally this pin will be a Key board scan pins function same as K1~K8.
In Hold condition this pin will stay in "High" level to control the Hold circuit and scan HD
input key. In Hold condition all key will not allow keying except HD, HF and Hook switch.
This pin has two functions
Normally this pin will be a Key board scan pins function same as K1~K8.
In MUTE condition this pin will stay in "High" level and output signal with the inverse of key
scan to control the MUTE circuit and scan input key. Any key input will release MUTE
condition.
This pin has two functions
Normally this pin will be a Key board scan pins function same as K1~K8.
The Tone/Pulse dialing Mute signal output pin. This pin will switch to "High" level during
Tone/Pulse dialing and hold function. Otherwise, this pin DC level stays "Low".
A 3.579545 MHz crystal must be crossed between Xin and Xout.
Handfree function Input pin accepts rising edge signal to turn "on" or turn "off" handfree
function. This pin is hysteresis input structure and built-in pull down resistor (typically 200
K ) .
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.
Hook Switch detects input pin, which is hysteresis input structure and without internal pull
up resistor.
DTMF (Dual Tone Multi-Frequency) output pin, In tone dialing mode, this pin will output
DTMF signal that is corresponding to key board 0~9, *, # key.
Pulse signal output pin that is NMOS open-drain. This pin is for pulse dialing. This output is
"Low" during pulse dialing blank duration and Flash operation active, otherwise will be "High
impedance".
Volume Add output pin , which is open drain structure.
Normally this pin will stay in "High Impedance". When Volume add active and dialer in OFF-
HOOK mode operting then this pin will output "Low".
XOUT
VAO
XIN
VSS
K7
K5
EM91865A
1
2
3
4
5
6
7
8
16
15
14
13
12
11
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13 MEMORY TONE/PULSE DIALER WITH HF, HD, REDIAL
9
K8
K3
K2
K1/HDO
DTMF
PO
HKS
VDD
K6/XMUTE
K4/MUTEO
XOUT
Function
VAO
XIN
VSS
HFI
K7
K5
EM91865B
AND VOLUME CONTROL FUNCTION
1
2
3
4
5
6
7
8
9
18
17
16
15
14
13
12
11
10
K8
K3
K2
K1/HDO
DTMF
PO
HKS
VDD
HFO
4.28.1999
EM91865
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