tza3010b NXP Semiconductors, tza3010b Datasheet - Page 6

• Manufacturer Part Number: tza3010b
• Description: Tza3010b 30 Mbits/s Up To 3.2 Gbits/s A-rate Tm Laser Driver
• Manufacturer: NXP Semiconductors

Philips Semiconductors
7
7.1
The TZA3010B operates with differential Positive Emitter
Coupled Logic (PECL) and Current-Mode Logic (CML)
data and clock inputs with a voltage swing from
100 mV to 1 V (p-p). It is assumed that both the data and
clock inputs carry a complementary signal with the
specified peak-to-peak value (true differential excitation).
The circuit generates an internal common mode voltage
for AC-coupled data and clock inputs and for single-ended
applications.
If V
and corresponds to an optical ‘one’ level of the laser.
7.2
The retiming function synchronizes the data with the clock
to improve the jitter performance. The data latch switches
on the rising edge of the clock input. The retiming function
is disabled when both clock inputs are below 0.3 V.
At start-up the initial polarity of the laser is unknown before
the first rising edge of the clock input.
2003 Apr 07
handbook, full pagewidth
30 Mbits/s up to 3.2 Gbits/s
A-rate
DIN
FUNCTIONAL DESCRIPTION
> V
Data and clock input
Retiming
DINQ
, the modulation current is sunk by pins LA
laser driver
V CCA
V CCD
TEST
DINQ
CINQ
GND
DIN
CIN
1
2
3
4
5
6
7
8
9
10
32
Fig.2 Pin configuration.
11
31
30
TZA3010B
12
13
29
6
7.3
The on-duration of the laser current can be adjusted from
R
pin PWA is 100 pF. Pulse width adjustment is disabled
when pin PWA is short-circuited to ground.
7.4
The output stage is a high-speed bipolar differential pair
with typical rise and fall times of 80 ps and with a
modulation current source of up to 100 mA when the
pins LA are connected to V
The modulation current switches between the LA and LAQ
outputs. For a good RF performance the inactive branch
carries a small amount of the modulation current.
Output LA is optimized for the laser allowing a 2 V dynamic
range and a 1.2 V minimum voltage. Output LAQ is
optimized for the dummy load.
The output stage is optimized for DC-coupled lasers.
Output BIAS is optimized for low voltage requirements
(0.4 V minimum for a 3.3 V laser supply; 0.8 V minimum
for a 5 V laser supply).
28
14
100 to +100 ps. The adjustment time is set by resistor
PWA
15
27
. The maximum allowable capacitive load on
Pulse width adjustment
Modulator output stage
16
26
19
18
17
25
24
23
22
21
20
MBL735
BIAS
GND
LA
LA
LAQ
LAQ
GND
PWA
CCO
.
Product specification
TZA3010B