TP5088WM National Semiconductor, TP5088WM Datasheet - Page 3

• Manufacturer Part Number: TP5088WM
• Description: IC DTMF GENERATOR SO14
• Manufacturer: National Semiconductor

Specifications of TP5088WM

• Function: DTMF Generator
• Voltage - Supply: 3.5V
• Current - Supply: 1.5mA
• Power (watts): 500mW
• Operating Temperature: -30°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: *
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Interface: -
• Number Of Circuits: -
• Other names: *TP5088WM

Connection Diagram
Functional Description
With the TONE ENABLE pin pulled low the device is in a
low power idle mode with the oscillator inhibited and the
output transistor turned off Data on inputs D0–D3 is ig-
nored until a rising transition on TONE ENABLE Data meet-
ing the timing specifications is latched in the oscillator and
output stage are enabled and tone generation begins The
decoded data sets the high group and low group program-
mable counters to the appropriate divide ratios These
counters sequence two ratioed-capacitor D A converters
through a series of 28 equal duration steps per sine wave
cycle On-chip regulators ensure good stability of tone am-
plitudes with variations in supply voltage and temperature
The two tones are summed by a mixer amplifier with pre-
emphasis applied to the high group tone The output is an
NPN emitter-follower requiring the addition of an external
load resistor to V
Table I shows the accuracies of the tone output frequencies
and Table II is the Functional Truth Table
Pin Descriptions
V
enced to V
also connected to this pin
V
are referenced to this pin
OSC IN OSC OUT (Pins 6 and 7) All tone generation tim-
ing is derived from the on-chip oscillator circuit A low-cost
Group
DD
SS
Group
Group
Tone
High
Low
f
f
H
(Pin 5) This is the negative voltage supply All voltages
L
(Pin 1) This is the positive supply to the device refer-
TABLE I Output Frequency Accuracy
SS
DTMF (Hz)
Standard
1209
1336
1477
1633
The collector of the TONE OUT transistor is
697
770
852
941
SS
Tone Output
Frequency
1206 0
1331 7
1486 5
1639 0
694 8
770 1
852 4
940 0
from Standard
% Deviation
b
a
a
b
b
b
a
a
Order Number TP5088WM or TP5088N
0 32
0 02
0 03
0 11
0 24
0 32
0 64
0 37
See NS Package M14B or N14A
Dual-In-Line Package
Top View
3
Figure 2 At all other times these inputs are ignored and may
3 579545 MHz A-cut crystal (NTSC TV color-burst) is need-
ed between pins 6 and 7 Load capacitors and a feedback
resistor are included on-chip for good start-up and stability
The oscillator is stopped when the TONE ENABLE input is
pulled to logic low
TONE ENABLE Input (Pin 2) This input has an internal
pull-up resistor When TONE ENABLE is pulled to logic low
the oscillator is inhibited and the tone generators and output
transistor are turned off A low to high transition on TONE
ENABLE latches in data from D0– D3 The oscillator starts
and tone generation continues until TONE ENABLE is
pulled low again
MUTE (Pin 8) This output is an open-drain N-channel de-
vice that sinks current to V
and no tones are being generated The device turns off
when TONE ENABLE is high
D0 D1 D2 D3 (Pins 9 10 11 12) These are the inputs for
binary-coded data which is latched in on the rising edge of
TONE ENABLE Data must meet the timing specifications of
be multiplexed with other system functions
TONE OUT (Pin 14) This output is the open emitter of an
NPN transistor the collector of which is connected internal-
ly to V
TONE OUT to V
of the high and low group tones superimposed on a DC
offset When not generating tones this output transistor is
turned off to minimize the device idle current
SINGLE TONE ENABLE (Pin 3) This input has an internal
pull-up resistor When pulled to V
tone mode and only a single tone will be generated at pin 14
(for testing purposes) For normal operation leave this pin
open-circuit or pull to V
GROUP SELECT (Pin 4) This pin is used to select the high
group or low group frequency when the device is in single
tone mode It has an internal pull-up resistor Leaving this
pin open-circuit or pulling it to V
group while pulling to V
quency at the TONE OUT pin
DD
When an external load resistor is connected from
SS
the output voltage on this pin is the sum
DD
TL H 5004 – 2
SS
SS
will generate the low group fre-
when TONE ENABLE is low
DD
SS
will generate the high
the device is in single