ELAN MICROELECTRONICS CORPORATION
EM92547A/B/D
CALLER ID FSK DECODER
ELAN MICROELECTRONICS CORP.
Office :
6-F1.,42, Sec.2, Chung Shaan N.
Road.,
Taipei, Taiwan, R.O.C.
TEL : (02) 5628813 EXT.686,687;5223065
FAX : (02) 5516348
TELEX : 21540 HTC, 22486 EHSIN
7F-1, No. 9 Prosperity 1st Rd.
Science-Based Industrial Park. Hsin Chu
City.
Taiwan, R.O.C.
TEL : (03) 5787505
FAX : (03) 5779095
Publication Release Date :
Agent :
EM92547A/B/D
CALLER ID FSK DECODER
________________________________________________________________________________________________________________________________________________________
* This specification are subject to be changed without notice.
1998
~ 1 ~
General Description
The EM92547 is a single-chip CMOS receiver IC designed to work in telephone
equipment incorporating Calling Number Delivery (CND) capabilities. CND capabilities
can be add to equipment such as telephone, adjunct units, answering machines, and
facsimile machines, by using the EM92547 and any standard microcontroller IC. The
EM92547 detects and qualifies the incoming ring signal, performs an energy detect on
incoming FSK signal, and demodulates the FSK data in accordance with BELL 202
standards. Integrating the above functions the equipment manufacturer a cost-effective
means of implementing CND capabilities into their products.
Features
Compatible with Bellcore GR-30-CORE (formerly as TR-NWT-000030).
Compatible with British Telecom (BT) SIN227 & SIN242.
FSK demodulator for Bell 202 and ITU-T V.23 (formerly as CCITT V.23)
On-chip ring detector
Ring detect and carrier detect output for MCU interrupt
Power down mode operation
On-chip band pass filter
FSK demodulation with energy detect
High input sensitivity
Low current consumption in power down mode
Single supply from 3.5V to 6V
Clock Frequencies: 3.58MHz or 455KHz for EM92547A
: 3.58MHz for EM92547B/D
Package series --- 16-pin DIP or 16-pin SOP (150 mil)
EM92547BP/DP for 16-pin DIP
EM92547BN/DN for 16-pin SOP (150 mil)
Application
adjunct units
answering machines
feature phones
fax machines
computer interface products
EM92547A/B/D
CALLER ID FSK DECODER
________________________________________________________________________________________________________________________________________________________
* This specification are subject to be changed without notice.
1998
~ 2 ~
Pin Assignments
Functional Block Diagram
TIP
RING DET2
PWR UP
SHORTDATA
CD
CLK SELECT
14
13
12
11
1
2
3
4
5
6
7
VDD
10
RING
RING DET1
OSCOUT
OSCIN
RING TIME
RD
NC
DVSS
8
9
DATA OUT
EM92547A
TIP
RING DET2
PWR UP
NC
CD
NC
1
2
3
4
5
6
7
VDD
RING
RING DET1
OSCOUT
OSCIN
RING TIME
RD
NC
DVSS
8
DATA OUT
EM92547B
15
16
14
13
12
11
10
9
15
16
TIP
RING DET2
PWR UP
CD
NC
1
2
3
4
5
6
7
VDD
RING
RING DET1
OSCOUT
OSCIN
RING TIME
RD
NC
DVSS
8
DATA OUT
EM92547D
14
13
12
11
10
9
15
16
SHORTDATA
Data Re-
timing
Ring
Det.
Circuit
Ring det1
Ring det2
Tip
Ring
Power
Up
FSK
Demod
Data Valid
Energy Det
Circuit
DATAOUT
/CD
Clock
OSCIN
OSCOUT
/RD
/Ring Time
/PWR UP
Band Pass
Filter
SHORTDATA
EM92547A/B/D
CALLER ID FSK DECODER
________________________________________________________________________________________________________________________________________________________
* This specification are subject to be changed without notice.
1998
~ 3 ~
Pin Descriptions
Symbol
I/O
Function
TIP
I
This input is connected to the tip line of the twisted pair.
RING
I
This input is connected to the ring line of the twisted pair.
RING DET1
I
This input is coupled to one end of the line through an attenuation
network. It is used to detect the occurrence of a valid ring signal.
RING DET2
I
This input is coupled to the other end of the line through an
attenuation network.
SHORTDATA
O
Data output pin without preamble message.
/RING TIME
O
A RC network should be connected to this pin. The RC time
constant is chosen to hold this pin voltage below 2.2V between
the peaks of the ringing signal.
/PWR UP
I
This active low input sets the chip into power up. When high, the
chip is put into a power down mode in the absence of a ring
signal. In this mode, only the ring detect circuitry is active.
VSS
Ground.
OSCOUT
O
This pin connects to the other side of the crystal oscillator.
OSCIN
I
This pin connects to 3.58MHz crystal oscillator or 455kHz
resonator. It can also be used as an external clock input.
CLK SELECT
I
A logic '1' on this pin to select 3.58MHz crystal oscillator, logic '0'
to select 455kHz resonator.
/RD
O
(ring detector)(active low)This output detects the presence of a
valid ring signal.
/CD
O
(carrier detect)(active low)This output indicates the presence of
in-band signals at the device input.
DATA OUT
O
The demodulated FSK data is output to this pin.
VDD
Power Supply Voltage.
NC
Non Connected.
Function Descriptions
The EM92547 is a CMOS device designed to support the Caller Number Deliver
feature, which is offered by the Regional Bell Operating Companies. The EM92547 CLID
comprises two paths: the signal path and the ring indicator path. The signal path consists of
an input differential buffer; a band pass filter, an FSK demodulator and a data valid with
carrier detect circuit. The ring detector path includes a clock generator, a ring detect circuit
and a power-up logic circuit.
In a typical application, the ring detector maintains the line continuously while all
other functions of the chip are inhibited. If a ring signal is sent, the ring detector wakes up
the oscillator and the main bias generator. This in turn activates the rest of the IC. Once
activated, a valid signal RI (ring indicator) is sent.
EM92547A/B/D
CALLER ID FSK DECODER
________________________________________________________________________________________________________________________________________________________
* This specification are subject to be changed without notice.
1998
~ 4 ~
A /PWR UP input pin is provided to activate the chip regardless of the presence of a
power ring signal. If /PWR UP is sent high, the IC can still power itself up whenever it
detects a valid ring signal, but will back to its normal power-down mode after a time period.
The input buffer accepts a differential AC coupled input signal through the TIP and
RING input and feeds this signal to a band pass filter. Once the signal is filtered, the FSK
demodulator decodes the information and sents it to a post filter. The output data is then
made available at DATA OUT pin. This data, as sent by the central office, includes the
header information (alternate "1" and "0") and 150msec of marking which precedes the date,
time and calling number. If no data is present, the DATA OUT pin is held in a low state.
This is accomplished by a carrier detect circuit which determines if the in-band energy is
high enough. If the incoming signal is valid and thus the demodulated data is transferred to
DATA OUT pin. If it is not, then the FSK demodulator is blocked. This device uses a 3.58
MHz crystal or a 455KHz(for EM92547A only) resonator as a timing source for all the
internal blocks.
* Ring detect circuit
When Vdd is applied to the circuit, the RC network will charge cap C1 to Vdd
holding /RING TIME off. If /PWRUP is also held at Vdd, the whole circuit will be in a
power down mode, and will consume less than 1uA of supply current. The resistor network
R2 to R4 attenuates the incoming power ring applied to the top of R2. The values given
have been chosen to provide a sufficient voltage at pin3, to turn on the Schmitt trigger input.
When Vt+ of the Schmitt is exceeded, cap C1 will discharge. This will initialize a partial
power up, and enable the ring detect circuit.
The value of R1 and C1 must be chosen to hold the /RING TIME pin voltage below
the Vt+ of the Schmitt between the individual cycle of the power ring. The values shown
will work for ring frequencies of 15.3 Hz minimum.
/PWR UP
VDD
/Ring Time
Ring det1
Ring det2
1.2V
Ring
Counter
Power Up
Logic
C1
R3
R4
R1
R2
/RD
(form bridge)
PDF 
ZIP