JPH0356871A - Deterioration detection circuit - Google Patents
Deterioration detection circuitInfo
- Publication number
- JPH0356871A JPH0356871A JP19117289A JP19117289A JPH0356871A JP H0356871 A JPH0356871 A JP H0356871A JP 19117289 A JP19117289 A JP 19117289A JP 19117289 A JP19117289 A JP 19117289A JP H0356871 A JPH0356871 A JP H0356871A
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- laser diode
- reference voltage
- memory
- temperature sensor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000006866 deterioration Effects 0.000 title claims abstract description 14
- 238000001514 detection method Methods 0.000 title claims description 8
- 230000010355 oscillation Effects 0.000 abstract description 7
- 238000012544 monitoring process Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 3
Landscapes
- Testing Of Individual Semiconductor Devices (AREA)
- Testing Of Optical Devices Or Fibers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野］
本発明はレーザダイオード劣化検出回路に関し、特に警
報の発振閾値の温度依存分を補償するレーザダイオード
劣化検出回路に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser diode deterioration detection circuit, and more particularly to a laser diode deterioration detection circuit that compensates for the temperature dependence of an alarm oscillation threshold.
［従来の技術］
従来、この種のレーザダイオード劣化検出回路は第２図
に示すように、レーザダイオード駆動電流モニタ電圧２
００を入力とする比較器２３と、アノードを電源Ｖｃｃ
に接続したダイオード２０と、一端を前記ダイオード２
０のカソードに、他端を端子２ＩＯに接続した抵抗２ｌ
と、一端を前記端子２１０に、也端を接地した抵抗２２
とを有し、前記端子２１０の電位２０２ を前記比較器
２３の他方のリファレンス入力としており、レーザダイ
オード劣化警報２０３の発振閾値の温度依存分の補償を
前記ダイオード２０を用いて補償していた。温度特性を
持つ前記ＬＤ駆動電流モニタ電圧２００に対して前記リ
ファレンス電圧２０２も同じ温度特性を持たせるために
、前記ダイオード２０の温度特性を用い、前記抵抗２ｌ
、抵抗２２に流れる電流を温度に応じ変化させ、ｎ；工
記端子２１０の電位に温度特性を持たせ、リファレンス
電圧２０２として前記比較器２３に入力し、レーザダイ
オード劣化警報２０３の発振閾値の温度依存分の補償を
行っていた。[Prior Art] Conventionally, this type of laser diode deterioration detection circuit uses a laser diode drive current monitor voltage 2 as shown in FIG.
A comparator 23 whose input is 00 and whose anode is connected to the power supply Vcc.
a diode 20 connected to the diode 2, and one end connected to the diode 2
Resistor 2l with the cathode of 0 connected to terminal 2IO and the other end connected to terminal 2IO
and a resistor 22 with one end connected to the terminal 210 and the other end grounded.
The potential 202 of the terminal 210 is used as the other reference input of the comparator 23, and the diode 20 is used to compensate for the temperature dependence of the oscillation threshold of the laser diode deterioration alarm 203. In order to make the reference voltage 202 have the same temperature characteristics as the LD drive current monitor voltage 200, which has temperature characteristics, the temperature characteristics of the diode 20 are used and the resistance 2l is
, the current flowing through the resistor 22 is changed according to the temperature; Compensation for dependence was provided.
［発明が解決しようとする課題］
上述した従来のレーザダイオード劣化検出回路では、レ
ーザダイオード劣化警報２０３の発振閾値の温度依存分
の補償は、外付けのダイオード２０の温度特性をレーザ
ダイオードの温度特性と同等としているので、実際の動
作温度におけるレーザダイオードの温度特性と外付けの
ダイオードの温度特性に差異が生じた場合、レーザダイ
オード劣化警報の発振閾値が動作温度によって異なって
しまい、正確な温度依存分の補償ができないという欠点
がある。[Problems to be Solved by the Invention] In the conventional laser diode deterioration detection circuit described above, compensation for the temperature dependence of the oscillation threshold of the laser diode deterioration alarm 203 is performed by changing the temperature characteristics of the external diode 20 to the temperature characteristics of the laser diode. Therefore, if there is a difference between the temperature characteristics of the laser diode and the temperature characteristics of the external diode at the actual operating temperature, the oscillation threshold of the laser diode deterioration alarm will differ depending on the operating temperature, and the accurate temperature dependence will vary. The disadvantage is that it cannot be compensated for.
本発明の目的は前記課題を解決したレーザダイオード劣
化検出回路を提供することにある。An object of the present invention is to provide a laser diode deterioration detection circuit that solves the above problems.
［課題を解決するための手段］
前記目的を達成するため、本発明のレーザダイオード劣
化検出回路においては、レーザダイオード駆動電流モニ
タ電圧及びリファレンス電圧を人力とし、比較結果を出
力する比較器と、周囲温度を検出してデイジタル値に変
換する温度センサと、前記温度センサの出力をアドレス
入力とし、記憶されているデータをアナログ値で前記リ
ファレンス電圧として出力するメモリとを有するもので
ある。[Means for Solving the Problems] In order to achieve the above object, the laser diode deterioration detection circuit of the present invention uses a laser diode drive current monitor voltage and a reference voltage manually, a comparator that outputs a comparison result, and a surrounding It has a temperature sensor that detects temperature and converts it into a digital value, and a memory that uses the output of the temperature sensor as an address input and outputs stored data as an analog value as the reference voltage.
（実施例］ 以下、本発明の一実施例を図により説明する。(Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
第１図は本発明の一実施例を示すブロック図である。FIG. 1 is a block diagram showing one embodiment of the present invention.
図において、レーザダイオード駆動電流モニタ電圧１０
０は比較器１３に入力される。温度センサ１１は、レー
ザダイオードモジュールの動作温度をモニタし、ディジ
タル値でモニタ結果を信号＋０１ として出力する。メ
モリｌ２は温度センサ１ｌの出力でアドレス値が指定さ
れる。そのアドレスには、温度センサ１１によって測定
されたレーザダイオードモジュール動作温度で、レーザ
ダイオード（ＬＤ）の温度特性によって変化するレーザ
ダイオード駆動電流に比例したリファレンス電圧を与え
るデータを書き込んでおく。各温度に対して与えられる
アドレスに同様なデータを書き込んでおく。ここで、メ
モリｌ２はＤ／Ａ変換器を有しており、出力はアナロク
値でリファレンス電圧１０２として与えられる。In the figure, the laser diode drive current monitor voltage 10
0 is input to comparator 13. The temperature sensor 11 monitors the operating temperature of the laser diode module and outputs the monitoring result as a digital value as a signal +01. The address value of the memory 12 is specified by the output of the temperature sensor 1l. At that address, data is written that provides a reference voltage proportional to the laser diode drive current that changes depending on the temperature characteristics of the laser diode (LD) at the laser diode module operating temperature measured by the temperature sensor 11. Similar data is written to the address given for each temperature. Here, the memory l2 has a D/A converter, and the output is given as a reference voltage 102 in an analog value.
比較器１ｌは前述したようにリファレンス電圧！０２が
、レーザダイオード（ＬＤ）モジュール動作温度におけ
るレーザダイオードの温度特性を反映して入力されてい
るので、レーザダイオード駆動電流モニタ電圧！００
を、レーザダイオードの温度特性を反映したリファレン
ス電圧１０２と比較し、発振閾値の温度依存分を補償し
た上でレーザダイオード劣化警報１０３を発出する。As mentioned above, the comparator 1l is the reference voltage! 02 is input reflecting the temperature characteristics of the laser diode at the operating temperature of the laser diode (LD) module, so the laser diode drive current monitor voltage! 00
is compared with a reference voltage 102 that reflects the temperature characteristics of the laser diode, and a laser diode deterioration alarm 103 is issued after compensating for the temperature dependence of the oscillation threshold.
［発明の効果］
以上説明したように本発明は周囲温度を検出しディジタ
ル値に変換する温度センサと、前記温度センサの出力値
でアドレス値が指定され、そのアドレスには温度センサ
によって測定されたレーザダイオードモジュール動作温
度でレーザダイオードの温度特性によって変化するレー
ザダイオード駆動電流に比例したリファレンス電圧を与
えるデータが書き込まれ、データをアナログ値で出力す
るメモリの出力を比較器のリファレンス電圧とすること
により、全動作温度範囲で発振閾値を高い精度で設定し
、正確に温度依存分を補償できる効果がある。[Effects of the Invention] As explained above, the present invention includes a temperature sensor that detects the ambient temperature and converts it into a digital value, an address value is specified by the output value of the temperature sensor, and the address value is specified by the output value of the temperature sensor. Data is written that provides a reference voltage proportional to the laser diode drive current, which changes depending on the temperature characteristics of the laser diode at the laser diode module operating temperature, and the output of the memory that outputs the data as an analog value is used as the reference voltage of the comparator. This has the effect of setting the oscillation threshold with high accuracy over the entire operating temperature range and accurately compensating for temperature dependence.
第１図は本発明の一実施例を示すブロック図、第２図は
従来例を示す回路図である。
ｌ・・・温度センサ ｌ２・・・メモリ３・・
・比較器
ＯＯ・・・レーザダイオード駆動電流モニタ電圧Ｏｌ・
・・信号 １０２・・・リファレンス電圧
０３・・・レーザダイオード劣化警報FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a conventional example. l...Temperature sensor l2...Memory 3...
・Comparator OO...Laser diode drive current monitor voltage OL・
...Signal 102...Reference voltage 03...Laser diode deterioration alarm
Claims (1)
レンス電圧を入力とし、比較結果を出力する比較器と、
周囲温度を検出してディジタル値に変換する温度センサ
と、前記温度センサの出力をアドレス入力とし、記憶さ
れているデータをアナログ値で前記リフアレンス電圧と
して出力するメモリとを有することを特徴とするレーザ
ダイオード劣化検出回路。(1) A comparator that receives the laser diode drive current monitor voltage and reference voltage as input and outputs a comparison result;
A laser characterized by having a temperature sensor that detects ambient temperature and converts it into a digital value, and a memory that uses the output of the temperature sensor as an address input and outputs stored data as an analog value as the reference voltage. Diode deterioration detection circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19117289A JPH0356871A (en) | 1989-07-24 | 1989-07-24 | Deterioration detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19117289A JPH0356871A (en) | 1989-07-24 | 1989-07-24 | Deterioration detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0356871A true JPH0356871A (en) | 1991-03-12 |
Family
ID=16270098
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19117289A Pending JPH0356871A (en) | 1989-07-24 | 1989-07-24 | Deterioration detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0356871A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6292497B1 (en) | 1997-10-28 | 2001-09-18 | Nec Corporation | Laser diode driving method and circuit |
| CN109839549A (en) * | 2017-11-24 | 2019-06-04 | 上海汽车集团股份有限公司 | The method of real-time and device of vehicle activation system working condition |
-
1989
- 1989-07-24 JP JP19117289A patent/JPH0356871A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6292497B1 (en) | 1997-10-28 | 2001-09-18 | Nec Corporation | Laser diode driving method and circuit |
| CN109839549A (en) * | 2017-11-24 | 2019-06-04 | 上海汽车集团股份有限公司 | The method of real-time and device of vehicle activation system working condition |
| CN109839549B (en) * | 2017-11-24 | 2021-07-27 | 上海汽车集团股份有限公司 | Real-time monitoring method and device for working state of vehicle starting system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6404139B1 (en) | Circuit for driving a light emitting elements display device | |
| EP0760934B1 (en) | Microprocessor controlled ring laser gyro power control system | |
| EP0693692A2 (en) | Voltage and resistance synthesizer using pulse width modulation | |
| JPH0356871A (en) | Deterioration detection circuit | |
| KR100202589B1 (en) | Temperature measuring device and temperature compensation method | |
| JPS612022A (en) | Method and device for controlling level of liquid in reservoir | |
| US20250279776A1 (en) | Temperature measuring circuit | |
| JP4445836B2 (en) | Sampling circuit and test apparatus | |
| JPS61107829A (en) | Bias current display system of semiconductor laser | |
| SU1120179A1 (en) | Temperature measuring device | |
| JP2001336989A (en) | Circuit for measuring temperature | |
| SU1068738A1 (en) | Device for measuring temperature having frequency output | |
| JPS6118687B2 (en) | ||
| JPS62154964A (en) | Output stabilizing circuit for semiconductor laser | |
| JPH0433151B2 (en) | ||
| JPH05312753A (en) | Humidity detection circuit | |
| JPH0466115B2 (en) | ||
| JPS60187868A (en) | Measuring apparatus | |
| JPH067608B2 (en) | Semiconductor laser light output adjustment device | |
| JPH0217069B2 (en) | ||
| JPH0416748B2 (en) | ||
| JPH06342032A (en) | Detecting circuit for laser diode deterioration | |
| JPS5999368A (en) | Method and apparatus for measuring inverse voltage of semiconductor element | |
| JPS59203963A (en) | Level decision circuit | |
| JPH05327432A (en) | Voltage comparator circuit |