Datasheet SM8224BM, SM8224BS Datasheet (NPC)

SM8224B

NIPPON PRECISION CIRCUITS INC.

Dual-Tone Receiver IC

OVERVIEW

The SM8224B is a receiver and decoder that supports the Bellcore TR-NWT-000030 and SR-TSV-002476
standards calling number identification (caller ID) and call waiting dual-tone signals. It has separate caller ID
signal and call waiting signal inputs, which allows the gain for each input to be adjusted independently. It is
fabricated in CMOS and features a power-down function, realizing low power dissipation operation.

FEATURES

■

TR-NWT-000030 and SR-TSV-002476 standards
(Bellcore)

■

Call waiting

■

FSK decoder

■

High input sensitivity

■

Independent input gain adjustment for caller ID
signal and call waiting signal inputs

■

Power-down mode

■

Crystal oscillator circuit built-in

■

Single supply operation:4.5 to 5.5V

■

Molybdenum-gate CMOS process

APPLICATIONS

■

Telephones, fax machines and modems that sup­port pre- and mid-conversation information ser­vices

■

Adapters for pre- and mid-conversation informa­tion service functions

■

Telephone answering machines

■

Facsimile machines

■

Computer peripheral equipment

PINOUT

(Top view)

OSCOUT

AGND

TIP

RING

TRQ

GND

OSCIN

MODE

TEST

DOUT

1

20

DT1
DT2

SM8224B

DTQ
S0
S1
VDD
CDET
CR
DTDET

10

11

STR

ORDERING INFORMATION

De vice Pack ag e

SM8224BM 20-pin SSOP
SM8224BS 20-pin SOP

NIPPON PRECISION CIRCUITS—1

PACKAGE DIMENSIONS

(Unit: mm)

20-pin SSOP

SM8224B

20-pin SOP

2.10 max

1.80 ± 0.10

0.10 ± 0.10

0.68 ± 0.12

7.40 max

7.20 ± 0.05

0.30 ± 0.10

0.10

0.13

0.65

M

5.30 ± 0.05

7.90 ± 0.20

1.30 ± 0.10

0.62 typ

0 to 8

0.20

±

0.6 ± 0.15

0.05

12.75 ± 0.10

1.27

0.41 ± 0.05

7.50 ± 0.10

10.31 ± 0.20

2.34 ± 0.10

0.20 ± 0.10

0.275 ± 0.045

0.51 ± 0.2 45

0.76 ± 0.25

0 to 8

NIPPON PRECISION CIRCUITS—2

BLOCK DIAGRAM

SM8224B

TIP

RING

TRQ

DT1

DT2

DTQ

AGND

Bias

Circuit

Crystal

Oscillator

Circuit

Filter

Filter

Filter

(2130Hz)

Filter

(2750Hz)

Power-down

Circuit

FSK

Demodulator

Carrier

Detector

Detector

Circuit

(2130Hz)

Level

Detector

Detector

Circuit

(2750Hz)

Level

Detector

Output
Circuit

Time-constant

Circuit

DOUT

CDET

STR
CR
DTDET

OSCIN OSCOUT MODE GNDVDD

S0

S1

NIPPON PRECISION CIRCUITS—3

SM8224B

PIN DESCRIPTION

Number Name I/O Function

1 AG N D O Analog ground output. Internal reference voltage (V
2 TIP I Tip input. Connected to the telephone line through a protection circuit
3 RING I Ring input. Connected to the telephone line through a protection circuit
4 T R Q O Input-stage amplifier gain-select output. Used to adjust the gain of the input-stage amplifier.
5 G ND – Ground. Connected to the system ground potential.
6 OSCIN I Crystal oscillator input. The cr ystal oscillator element is connected between this pin and OSCOUT.
7 OSCOUT O Crystal oscillator output. The crystal oscillator element is connected between this pin and OSCIN.
8 MODE I When MODE is HIGH, and S1 and S0 are both LOW, the device is in power-down state. See table 2.
9 TEST – TEST pin. Set OPEN when normal using.

10 DOUT O Data output. Demodulated FSK signal output. HIGH level output when CDET goes HIGH.

11 STR O

12 DTDET O Dual-tone detector output. HIGH-level output when dual tone is detected.

13 C R I/O

14 CDET O FSK signal carrier detector output. L OW -level when active carrier is detected.
15 VD D – Supply
16 S1 I Function select bit 1. Selects the device mode in combination with S0 and MODE. See table 2.
17 S0 I Function select bit 1. Selects the device mode in combination with S1 and MODE. See table 2.
18 D TQ O Dual-tone signal input-stage amplifier output. Used to adjust the gain of the input-stage amplifier.
19 DT 2 I Dual-tone signal input-stage operational amplifier inverting input
20 DT 1 I Dual-tone signal input-stage operational amplifier non-inverting input

Dual-tone confirmation output. Function is selected by S0 and S1. See table 2.
Dual-tone confirmation: Active-LOW output when dual tone detection signal passes through RC time
constant delay circuit.

Dual tone RC time constant circuit connection. The dual tone detection signal passes through the RC
network to generate the ST R signal.

/2) output level

DD

NIPPON PRECISION CIRCUITS—4

−

−

−

° C

∆

−

−

° C

SPECIFICATIONS

Absolute Maximum Ratings

GND = 0V

Parameter Symbol Condition Rating Unit

Supply voltage range V
Input voltage range V
Po w er dissipation P
Storage temperature range T

Recommended Operating Conditions

GND = 0V

DD

IN

D

stg

SM8224B

−

−

0.5 to 7.0 V

0.3 to V

+ 0.3 V

DD

44 m W

40 to 125

Parameter Symbol Condition

Supply voltage V
Clock frequency f
Clock frequency accuracy
Operating temperature T

Electrical Characteristics

V

= 5.0V ± 0.5V, GND = 0V, f

DD

Parameter Symbol Condition

Supply current consumption I

Pow er-down current I

MODE, S0, S1 LOW -level input
voltage

MODE, S0, S1 HIGH-level input
voltage

OSCIN LOW-level input voltage V
OSCIN HIGH-level input voltage V
DOUT, STR, DTDET, CR, CDET

L O W-level output current
DOUT, STR

HIGH-level output current
TIP, RING, DT1, DT2, MODE, S1,

S0 input leakage current

, DTDET, CR, CDET

DD

CLK

f

C

opr

= 3.579545MHz, T

CLK

No analog signal input, no output load,

DD

S1 = 0V, S0 = V
No analog signal input, other inputs =

V

DPD

V

V

I

OL

I

OH

I

IL1

IH1

IL2

IH2

IN

or 0V, no output load, S1 = 0V,

DD

S0 = 0V, MODE = V

min typ ma x

4.5 – 5.5 V
– 3.579545 – MH z

0.1 – +0.1 %
20 – 85

= − 20 to 85 ° C unless otherwise noted.

a

min typ ma x

, MODE = 0V

DD

– – 8.0 m A

––15µA

DD

– – 0.3V

0.7V

DD

– – 0.3V

0.7V

DD

2––mA

––

1– 1µA

Rating

Unit

Rating

Unit

DD

V

––V

DD

V

––V

0.8 mA

NIPPON PRECISION CIRCUITS—5

– − 43 −

SM8224B

AC Electrical Characteristics

Measurement conditions: R1 = 430k Ω , R2 = 34k Ω , R3 = 390k Ω , C1= 0.22 µ F

FSK decoder

V

= 5.0V ± 0.5V, GND = 0V, f

DD

= 3.579545MHz, T

CLK

= − 20 to 85 ° C unless otherwise noted.

a

−

− 50 −

−

−

−

Parameter Symbol Condition

Input sensitivity –

1

S/N ratio
Carrier detection sensitivity C D
Carrier non-detection sensitivity C D
Oscillator frequency f

1. Ma rk signal and SPACE signal are same level.
Noise: Random noise from 200Hz to 3400Hz.

FSKSNR 20 – – dB

ON

OFF

CLK

typ

min typ m ax

0.1% 3.579545 typ + 0.1% M Hz

Rating

43 CD

46 – dBm

ON

37.78 dB m

Unit

dBm

Dual tone detector

V

= 5.0V ± 0.5V, GND = 0V, f

DD

Parameter Symbol Condition

Frequency (low frequency) f
Frequency (high frequency) f
Detection frequency deviation 1.1 – – %
Non-detection frequency deviation 3.5 – – %
Detection sensitivity
Non-detection sensitivity ––
Signal level deviation ––6dB

= 3.579545MHz, T

CLK

L

H

= − 20 to 85 ° C unless otherwise noted.

a

Rating

min typ m ax

– 2130 – Hz
– 2750 – Hz

37.78 – – dB m

43.78 dB m

Unit

Note: (S0, S1, MODE) = (V

, 0V, 0V)

DD

Input-stage amplifier Characteristics

V

= 5.0V ± 0.5V, GND = 0V, f

DD

Parameter Symbol Condition

Input leakage current I
DC open-loop voltage gain G
Unity gain frequency f
Load capacitance C
Load resistance R

= 3.579545MHz, T

CLK

IN

OL

C

L

L

= − 20 to 85 ° C unless otherwise noted.

a

Rating

min typ m ax

––1µA
30 – – dB
80 – – kHz

– – 100 pF
50 – – k Ω

NIPPON PRECISION CIRCUITS—6

Unit

Timing Characteristics

FSK decoder

V

= 5.0V ± 0.5V, GND = 0V, f

DD

= 3.579545MHz, T

CLK

SM8224B

= − 20 to 85 ° C unless otherwise noted.

a

Parameter Symbol Condition

Pow er-down release to start-up time t
Carrier detection ON time t
Final data to carrier detection OFF time t

DOSC

DAQ

DCH

min typ m ax

–5–ms

2.5 – 10 m s
3–15ms

Rating

Unit

Output timing)

V

= 5.0V ± 0.5V, GND = 0V, f

DD

= 3.579545MHz, T

CLK

= − 20 to 85 ° C, FSK input data = 1200 ± 12 baud

a

unless otherwise noted.

Parameter Symbol Condition

STR, DOUT rise time t
STR, DOUT fall time t
Input/output delay t
DOUT data rate 1188 1200 1212 baud

r0

f0

IDD

Input to DOUT – – 5 m s

min typ m ax

– – 200 ns
– – 200 ns

Rating

Unit

NIPPON PRECISION CIRCUITS—7

TIMING DIAGRAMS

FSK demodulator timing

SM8224B

1st Ring

L1/L2

PDWN

CDET

DOUT

OSCOUT

P DWN is an inter nal signal (set by S0, S1, MODE)

Output timing

DOUT

tDOSC

101010... 1 Data

tDAQ

101010...1

Data

2nd Ring

tDCH

DOUT

STR

Data timing

TIP/RING

STR

DOUT

90%
10%

tr0 tf0

90%
10%

tf0 tr0

START

STOP

0 b0 b1 b2 b3 b4 b5 b6 b7 1 0 b0 b1 b2 b3 b4b6 b7 1 b5 b6

STOP

START

tIDD

START

b4 b5 b6 b7 b0 b1 b2 b3 b4 b5 b6 b7 b0 b1 b2 b3 b4

STOP

NIPPON PRECISION CIRCUITS—8

FUNCTIONAL DESCRIPTION

SM8224B

The SM8224B receiver with caller ID service con­forms to the Bellcore standards. It incorporates FSK
demodulator and dual-tone detection functions in a
single chip. It has a dedicated dual-tone signal input

tone signal input amplification can be set indepen­dently. This allows systems can be easily constructed
that provide pre- and mid-conversation information
services.

so that the FSK signal input amplification and dual-

FSK Demodulator

Calling number identification service is sent as an
FSK signal, and the SM8224B FSK demodulator
processes this signal.

The FSK signal conforms to the following Bellcore
standard.

Table 2. Function select

S1 S0 MODE Function ST R

LOW LOW HIGH Power-down HIGH
HIGH LOW LOW Dual-tone detection from DT1/DT2
LOW HIGH LOW FSK and dual-tone detection from TIP/RING L OW (dual tone confirmation)
HIGH HIGH LOW FSK detection from TIP/RING HIGH
LO W LO W L OW Test mode

1. DT1, DT2, DTQ are active in this mode only.

2. Test mode should not be used.
Note: S1, S0, MODE setting should be used from above combination except Test mode.

2

Table 1. FSK signal

Parameter Description

Modulation type
Logic “1” data (mar k) 1200 ± 12 Hz

Logic “0” data (space) 2200 ± 22 Hz
Signal level (mark)
Signal level (space)−36 to −12 dBm
Data transfer rate 1200 ± 12 baud

1

Continuous-phase binary frequency-shift­keying

−

32 to −12 dBm

LO W (dual tone confirmation)

Dual T one Detector

When using mid-conversation information services,
2 mixed signals of 2130Hz and 2750Hz are sent on
lines L1 and L2. The SM8224B detects the 2 signals
from the background noise. It uses 2 separate high­order filters with center frequencies of 2130Hz and
2750Hz to detect the presence of the signal frequen­cies.

In series with the filters are level detectors. When the
input level exceeds the preset rating, the signal is

detected. When the input level is below the rating,
the signal is not detected.

If both the 2130Hz and 2750Hz signals are simulta­neously detected, DTDET goes HIGH and starts
charging the time constant circuit comprised by an
external capacitor and external resistor. When the
time constant circuit voltage rises above a fixed volt­age level, STR signal goes LOW to indicate dual
tone detection.

NIPPON PRECISION CIRCUITS—9

TYPICAL APPLICATION CIRCUIT

Speech

Network

Circuit

Protection

Circuit

L1

L2

R1

1%

C1
5%

R1

C1

1%

5%

VDD

R6

1%

C2

5%

C2

R6

5%

VDD

1%

R2

1%

R9
1%

R5

1%

R2

1%

0.1µF
20%

SM8224B

R8
1%

R4

1%

R3

1%

AGND

TIP

RING

TRQ

GND

OSCIN

OSCOUT

MODE

TEST

DOUT

DT1

DT2

DTQ

VDD

CDET

CR

DTDET

STR

R7
1%

S0

S1

VDD

0.1µF
20%

Note : Please set this capacitor
nearby IC pin.

Symbol Rating

R

1

R

2

R

3

C

1

R

4

R

5

R

6

R

7

C

2

R

8

R

9

1. Circuit values are preliminary.

1

330 k

27 k

220 k

0.001

47.5 k

60.4 k

430 + 34 k

390 k

0.22

52.3 k

60.4 k

Unit

Ω
Ω
Ω

µ

F

Ω
Ω
Ω
Ω

µ

F

Ω
Ω

NIPPON PRECISION CIRCUITS—10

SM8224B

NIPPON PRECISION CIRCUITS INC. reserves the right to make changes to the products described in this data sheet in order to
improve the design or performance and to supply the best possible products. Nippon Precision Circuits Inc. assumes no responsibility for
the use of any circuits shown in this data sheet, conveys no license under any patent or other rights, and makes no claim that the circuits
are free from patent infringement. Applications for any devices shown in this data sheet are for illustration only and Nippon Precision
Circuits Inc. makes no claim or warranty that such applications will be suitable for the use specified without further testing or modification.
The products described in this data sheet are not intended to use for the apparatus which influence human lives due to the failure or
malfunction of the products. Customers are requested to comply with applicable laws and regulations in effect now and hereinafter,
including compliance with export controls on the distribution or dissemination of the products. Customers shall not export, directly or
indirectly, any products without first obtaining required licenses and approvals from appropriate government agencies.

NIPPON PRECISION CIRCUITS INC.
4-3, Fukuzumi 2-chome

Koto-ku, Tokyo 135-8430, Japan

NIPPON PRECISION CIRCUITS INC.

Telephone: [phone]
Facsimile: 03-3642-6698

NC9910AE 2000.02

NIPPON PRECISION CIRCUITS—11