U3750BM
TELEFUNKEN Semiconductors
Parameters
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
DTMF generation Pin 4 grounded
Tone frequency accuracy
(confidence tone included)
Low group tone level
(depends on external
components)
V
= 3.5 V
–0.4
–10
+0.25
–6
%
RAM
(Note 2)
Measured on 600
I = 28 mA
L
–8
–6
2
dBm
figure 3
High group tone level
(depends on external
components)
(Note 2)
Measured on 600
I = 28 mA
L
–8
1
–4
3
dBm
dB
figure 3
Preemphasis (depends on
external components)
(Note 2)
Measured on 600
I = 28 mA
L
figure 3
DTMF distortion (depends (Note 2 and note 3)
on external components)
Measured on 600
3.5
%
I = 28 mA,
L
300 < f < 3400 Hz
figure 3
DTMF transmission time
DTMF interdigit time
t
80.2
89.2
82.4
89.2
ms
ms
MF
t
IMF
Transmission mute tm
Confidence tone
FCT frequency
Tone level (depends on
external components)
169.4
171.6
ms
MF
Only by serial bus
Measured on 600
440.9
–9
Hz
dBm
I = 25 mA
L
figure 3
Note 1: sending gain: G = V /V with the values of
S
L
MI
R
AG1
and R
(figure 3) so the maximum gain
AG2
is at 28 mA and the minimum gain is at 60 mA.
Note 2: For DTMF measurements, close switches S1 and
S3 and select each group of frequencies on the
keyboard.
Note 3: The level of each harmonic on line is under the
limited curve given below with the filter compo-
nents value chosen for the test.
Figure 1
Rev. A1: 16.07.1996
7 (20)
TEMIC [ TEMIC SEMICONDUCTORS ]
