- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄24778 > 935263643551 (NXP SEMICONDUCTORS) SPECIALTY INTERFACE CIRCUIT, PQFP48 PDF資料下載
參數(shù)資料
| 型號(hào)： | 935263643551 |
| 廠商： | NXP SEMICONDUCTORS |
| 元件分類： | 其它接口 |
| 英文描述： | SPECIALTY INTERFACE CIRCUIT, PQFP48 |
| 封裝： | PLASTIC, SOT-313, LQFP-48 |
| 文件頁數(shù)： | 31/31頁 |
| 文件大?。?/td> | 726K |
| 代理商： | 935263643551 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁當(dāng)前第31頁
1999 Aug 24
9
Philips Semiconductors
Product specication
SDH/SONET STM16/OC48 laser drivers
OQ2545HP; OQ2545BHP
Automatic laser shutdown
A HIGH-level (TTL) on pin ALS switches off the laser
modulation and bias currents. This function allows the
circuit to be switched off in the event of an optical system
malfunction or for system maintenance. When not
connected, pin ALS is pulled to a LOW-level (TTL) by an
internal pull-down resistor.
Data monitoring
Pins MON and MONQ can be used as data monitor
outputs. They need to be AC-coupled, e.g. to a 50
matched RF amplifier with sufficient bandwidth.
Output polarity selection
Pin SMOD is used to set the correct logic assignment
between the data input on pins DIN and DINQ (or
pins DLOOP and DLOOPQ) and the data output on
pins LA, LAQ, MON and MONQ. This is necessary
because a directly modulated laser diode and an EAM
have different output voltage requirements.
If a laser diode is used and connected between pin LA and
ground, a high current through pin LA corresponds to a
logic HIGH, while a low current through pin LA
corresponds to a logic LOW.
The opposite is the case with an EAM, where a high
current (i.e. a large voltage across the load) activates the
EAM, thereby causing a logic LOW. Therefore, an
inversion is needed between input and output. This
happens in the second multiplexer when pin SMOD is
connected to VEE1. When left open-circuit, pin SMOD is
pulled-up to ground, which is the laser diode setting.
Modulation current setting
Pin SIMOD is used to adjust the modulation current on
pins LA and LAQ (see Fig.6). This is achieved by
regulating the internal current mirror, which serves as a
reference current for the modulation driver. The reference
port of the control operational amplifier is connected to
ground through an internal 4 k
resistor, thus establishing
a ‘virtual earth’ on pin SIMOD (DC level is 0 V).
An external (approximately) 4 k
resistor connected to an
adjustable voltage source is needed to regulate the
internal current mirror. This adjustable voltage source can
be a part of the laser current control box (see Fig.15).
The ratio between the current into pin SIMOD and the total
modulation current depends on the polarity setting via
pin SMOD. When pin SMOD=0V the value of
Imod =92 × ISIMOD (approximately) and whereas
pin SMOD = VEE1 the value of Imod = 107 × ISIMOD
(approximately).
Fig.6 Schematic of laser modulation outputs.
handbook, full pagewidth
k
× ISIMOD
ISIMOD
SIMOD
4 k
100
100
VEE2
71
× k × ISIMOD(1)
LA
LAQ
MGL733
+
(1) k = 1.3 when pin SMOD = 0 V.
k = 1.5 when pin SMOD = VEE1.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| 0674.750 | Axial Lead and Cartridge Fuses - Ceramic Body |
| 935183530112 | HC/UH SERIES, HEX 1-INPUT INVERT GATE, PDSO14 |
| 933669160652 | HCT SERIES, HEX 1-INPUT INVERT GATE, PDIP14 |
| 935174470118 | HCT SERIES, HEX 1-INPUT INVERT GATE, PDSO14 |
| 935183540118 | HCT SERIES, HEX 1-INPUT INVERT GATE, PDSO14 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| 935264217557 | 制造商:NXP Semiconductors 功能描述:SUB ONLY IC |
| 935267356112 | 制造商:NXP Semiconductors 功能描述:IC TEA1507PN |
| 935268081112 | 制造商:NXP Semiconductors 功能描述:SUB ONLY IC |
| 935268721125 | 制造商:NXP Semiconductors 功能描述:Buffer/Line Driver 1-CH Non-Inverting 3-ST CMOS 5-Pin TSSOP T/R |
| 935269304128 | 制造商:ST-Ericsson 功能描述:IC AUDIO CODEC W/TCH SCRN 48LQFP |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。