AK2570 Datasheet PDF - AKM

www.Datasheet-PDF.com

AK2570
AKM

Part Number AK2570
Description Feed Forward APC LSI
Page 27 Pages


AK2570 datasheet pdf
View PDF for PC
AK2570 pdf
View PDF for Mobile


No Preview Available !

ASAHI KASEI
[AK2570]
AK2570
Feed Forward APC LSI for LD Module
DESCRIPTION
AK2570 is the monolithic CMOS LSI has the function of Feed Forward Automatic Power Control (APC)for the
Laser Diode (LD) module and maintains the emission intensity of the LD module constant with the high accuracy.
For stabilizing the emission intensity of the LD module affected by the ambient temperature, AK2570 feeds the
compensation voltage from the 2channels - 8bits D to A converter to control the Bias- and the Modulation- current
for the LD module. The compensation voltage corresponds to the temperature characteristic data of the LD module
retained in the on-chip EEPROM and the ambient temperature detected by the on-chip thermo-sensor.
www.DataShAeeKt42U5.c7o0moutputs the alarm signal for the weakened LD emission caused by the aging degradation with comparing
the alarm threshold level and the signal from the monitoring Photo Diode (PD).
The data of the compensation voltage and the alarm threshold level retained in the on-chip EEPROM can be set to
suit for the characteristics of each LD module.
FEATURE
Realizing all APC function on 1 silicon chip
Controlling the driving current (the Bias- and the Modulation- current) for the LD module
* Consisting of the 2channels - 8bits D to A converter and the Op-amp
EEPROM (Electrically Erasable Programmable Read Only Memory)
* The Non-volatile Memory
* The memory capacity : Address 9bits × Data 16bits
* Retaining the data of the compensation voltage and the trimming data of the T-SENSE offset voltage and the ALM timing for
each LD module
On-chip Thermo-sensor (T-SENSE)
* Detecting the ambient temperature and converting the detected temperature to the voltage
On-chip Alarm circuit
* Outputting the alarm signal for the weakened LD emission caused by the aging degradation
On-chip Oscillator
On-chip Power on reset circuit
Serial interface
+3.3V±10% single voltage supply
Low power consumption (30mA [max])
Small package (20pin - SSOP : 7.9mm ×7.4mm)
<MS0115-E-00>
1
2001/10



No Preview Available !

ASAHI KASEI
CS SK DI DO
Control
www.DataSheet4U.com
EEPROM
Oscillator
BIAS
VREF
Power on Reset
BLOCK DIAGRAM
[AK2570]
Register
RDA1
DA1 (8bits)
RDA2
RDA3
RVPD
RTMP
RINT
DA2 (8bits)
DA3 (8bits)
AD1 (8bits)
AD2 (8bits)
T-SENSE
RATRM
AMP1
AMP2
Comparator
ALMOUT
ALM Timing Generator
DAOUT1
FB1
SHUTDN
DAOUT2
FB2
VPDIN
ALM
ENVIN
<MS0115-E-00>
AVDD AVSS DVDD DVSS
TEMPTEST ALMMOD1 ALMMOD0
2
2001/10



No Preview Available !

ASAHI KASEI
[AK2570]
AK2570 consists of these circuit blocks as below.
Circuit block
Oscillator
VREF
T-SENSE
AD1
www.DataSheet4U.com
AD2
DA1,
AMP1
DA2,
AMP2
DA3, ALMOUT,
Comparator, ALM
Timing Generator
EEPROM
Register
Control
Power on Reset
Functional description
This circuit generates the standard clock that settles the timing for the sequence of the
internal circuit in Self-operation mode (Ordinary mode).
This circuit generates the reference voltage for the A to D converter, the D to A converter
and the T-SENSE.
This circuit is the thermo-sensor, outputs the voltage corresponding to the ambient
temperature, i.e. the temperature to voltage converter, and transfers this output voltage to
AD2. Also it integrates the offset adjustment circuit that cancels the distribution.
The A to D converter encodes the input voltage at VPDIN-pin (the signal from the
monitor PD) to the 8bits digital data. It is possible to read the encoded data of monitor PD
signal (the reference data for RDA3) held in RVPD register and to set the alarm threshold
level for the degraded LD in Training mode.
The A to D converter encodes the T-SENSE output signal to the 8bits digital data. In
Self- operation mode, the encoded data of the ambient temperature detected by the
T-SENSE is converted to the EEPROM address and utilized for reading the temperature
characteristic data of the LD retained in the EEPROM. In Training mode, it is possible
to read the encoded data of the detected temperature held in RTMP register.
This block consists of the D to A converter and the Op-amp and controls the Bias- or the
Modulation- current for the LD. DA1 decodes the 8bits digital data held in RDA1 register
to the compensation voltage for the temperature drift of the LD. Inputting the Hlevel
signal to SHUTDN-pin makes that DAOUT1-pin outputs 0V (min.).
This block consists of the D to A converter and the Op-amp and controls the Bias- or the
Modulation- current for the LD. DA2 decodes the 8bits digital data held in RDA2 register
to the compensation voltage for the temperature drift of the LD. Inputting the Hlevel
signal to SHUTDN-pin makes that DAOUT2-pin outputs 0V (min.).
This block outputs the Hlevel alarm signal from ALM-pin in the case that the
monitoring PD signal becomes lower than the alarm threshold level retained in the
EEPROM and held in RDA3 register, and this case is caused by the aging degradation.
This memory is the non-volatile memory, has the capacity Address 9bits × Data 16bits
and retains the data as below,
1. The temperature compensation data for the LD (transferred to RDA1 and RDA2 registers)
and the alarm threshold level data for the degraded LD (transferred to RDA3 register)
corresponding to the ambient temperature (the output from the T-SNESE and AD2).
2. The trimming data for the T-SENSE offset and the ALMOUT timing.
This circuit temporarily stores the ambient temperature data (in RTMP register), the
temperature compensation data for the LD (in RDA1 and RDA2 registers), the alarm
threshold level data (in RDA3 register) and so on.
This circuit controls the internal circuit, e.g. registers, with the serial interface.
At Power ON, this circuit initializes the data in all registers (see p.9) and sets AK2570 in
Self-operation mode.
<MS0115-E-00>
3
2001/10



No Preview Available !

ASAHI KASEI
[1] TEMPTEST
[2] BIAS
[3] FB1
[4] DAOUT1
[5] FB2
[6] DAOUT2
[7] AVDD
[8] AVSS
[9] VPDIN
www.DataSheet4U.com
[10] ALM
PIN ASSIGNMENT
[AK2570]
[20] ALMMOD0
[19] ALMMOD1
[18] SHUTDN
[17] DVDD
[16] DVSS
[15] DO
[14] DI
[13] SK
[12] CS
[11] ENVIN
No Name I/O Type
Function
AC load DC load Remark
1 TEMPTEST O Analog Output the voltage generated by the T-SENSE (Factory use)
2 BIAS O Analog Output the current reference determined by the external resistance
[Note 1]
3 FB1 I Analog Input the feed back voltage to AMP1 for the gain control
4 DAOUT1 O Analog
Output the compensation voltage [1] for the LD
< 20pF
5 FB2 I Analog Input the feed back voltage to AMP2 for the gain control
6 DAOUT2 O Analog
Output the compensation voltage [2] for the LD
< 20pF
7 AVDD I Power
Supply the power for the analog part (+3.3V)
8 AVSS I Power
Ground the analog part (0V)
9 VPDIN I Analog
Input the signal of the monitor PD
10 ALM O CMOS
Output the aging alarm
< 20pF
11 ENVIN I CMOS
Input the envelope signal used at burst transmission
12 CS
I CMOS
Input the Chip Select signal with the serial interface
[Note 2]
13 SK
I CMOS
Input the Shift clock with the serial interface
14 DI
I CMOS
Input the Data with the serial interface
15 DO O CMOS
Output the Data with the serial interface
< 100pF
16 DVSS I Power
Ground the digital part (0V)
17 DVDD I Power
Supply the power for the digital part (+3.3V)
18 SHUTDN I CMOS
Input the shut down signal for DA1 and DA2
See P.15
19 ALMMOD1 I CMOS
Input the select signal [1] for the aging alarm mode
See P.15
20 ALMMOD0 I CMOS
Input the select signal [0] for the aging alarm mode
See P.15
[Note 1] : Kindly insert the external register 75k(±1%) between BIAS-pin and AVSS.
[Note 2] : It is necessary to input the Llevel signal to CS-pin at Power ON.
<MS0115-E-00>
4
2001/10



AK2570 datasheet pdf
Download PDF
AK2570 pdf
View PDF for Mobile


Related : Start with AK257 Part Numbers by
AK2570 Feed Forward APC LSI AK2570
AKM
AK2570 pdf
AK2571 Single-Chip Automatic Power/Temperature Control AK2571
AKM
AK2571 pdf
AK2572 APC for Burst Mode Applicable Direct Modulation Laser Diode AK2572
AKM
AK2572 pdf
AK2573A 125M / 156M Laser Diode Driver APC AK2573A
AKM
AK2573A pdf
AK2574 156M Laser Diode Driver APC AK2574
AKM
AK2574 pdf

Index :   0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z   

This is a individually operated, non profit site. If this site is good enough to show, please introduce this site to others.
Since 2010   ::   HOME   ::   Contact