TZA3024T View Datasheet(PDF) - Philips Electronics
Part Name
Description
Manufacturer
TZA3024T Datasheet PDF : 20 Pages
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Philips Semiconductors
SDH/SONET STM4/OC12 postamplifiers
Objective specification
TZA3024T; TZA3024U
Bonding pad locations
handbook, full pagewidth
AGND
n.c.
AGND
1.58(1) DIN
mm
DINQ
AGND
TEST
VCCA
32
4
1 32 31 30 29 28
27
5
26
6
25
7
x
24
8
0
0
23
9
y
22
10
TZA3024U
21
11
20
12 13 14 15 16 17 18 19
VCCD
TEST
DGND
DOUT
DOUTQ
DGND
TEST
DGND
(1) Typical value.
Pad size: 90 × 90 µm.
1.58 mm(1)
MBK853
Fig.3 Bonding pad locations of TZA3024U.
FUNCTIONAL DESCRIPTION
The TZA3024 accepts up to 622 Mbits/s SDH/SONET
data streams, with amplitudes from 2 mV(p-p) up to 1 V(p-p)
single-ended. The input signal will be amplified and limited
to differential PECL output levels (see Fig.1).
The input buffer A1 presents an impedance of
approximately 4.5 kΩ to the data stream on the inputs
DIN and DINQ. The input can be used both single-ended
and differential, but differential operation is preferred for
better performance.
Because of the high gain of the postamplifier, a very small
offset voltage would shift the decision level in such a way
that the input sensitivity decreases drastically. Therefore a
DC offset compensation circuit is implemented in the
TZA3024, which keeps the input of buffer A3 at its toggle
point in the absence of any input signal.
An input signal level detection is implemented to check if
the input signal is above the user-programmed level.
The outcome of this test is available at the PECL
outputs ST and STQ. This flag can also be used to prevent
the PECL outputs DOUT and DOUTQ from reacting to
noise in the absence of a valid input signal, by connecting
the output STQ to the input JAM. This insures that data will
only be transmitted when the input signal-to-noise ratio is
sufficient for low bit error rate system operation.
PECL logic
The logic level symbol definitions for PECL are shown in
Fig.4.
Input biasing
The input pins DIN and DINQ are DC biased at
approximately 2.55 V by an internal reference generator
(see Fig.5). The TZA3024 can be DC-coupled, but
AC-coupling is preferred. In case of DC-coupling, the
driving source must operate within the allowable input
signal range (2.0 V to VCCA + 0.5 V).
Also a DC offset voltage of more than a few millivolts
1998 Aug 18
6
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