tza3050 NXP Semiconductors, tza3050 Datasheet - Page 17

• Manufacturer Part Number: tza3050
• Description: Tza3050 30 Mbits/s Up To 1.25 Gbits/s Burst Mode Laser Driver
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 14806
Product data sheet
12.3 Average loop control
A simplified application using the TZA3050 with average loop control and a DC-coupled
laser at 3.3 V or 5 V laser voltage is illustrated in
determined by the resistor R
BIASOUT output connected to the BIASIN input. The modulation current is determined by
the MODIN input voltage, which is generated by the resistor R
source current of the MODIN pin.
The average loop setting is maintained between bursts with a capacitor connected to pin
CBIAS. When pin ENABLE is HIGH, the internal average loop regulates the average
power. When pin ENABLE is LOW, an internal switch is opened and the previous average
loop state is stored on the CBIAS capacitor.
Fig 8. TZA3050 with DC-coupled laser and average loop control
3.3 V
3.3 V
ALRESET
TEST
V
DINQ
CINQ
V
GND
CCA
CCD
DIN
CIN
1
2
3
4
5
6
7
8
9
Rev. 03 — 7 April 2005
10
32
11
31
AVR
30
12
. The average loop controls the bias current with the
TZA3050
30 Mbits/s up to 1.25 Gbits/s burst mode laser driver
13
29
14
28
3.3 V or 5 V
15
27
16
26
Figure
19
18
17
25
24
23
22
21
20
BIAS
GND
LA
LA
LAQ
LAQ
GND
8. The average power level is
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
MODIN
and the 100 A
laser with
monitor diode
TZA3050
mce139
17 of 24