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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. AK2570 outputs 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 x 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 * +3.3V10% single voltage supply * Low power consumption (30mA [max]) * Small package (20pin - SSOP : 7.9mm x7.4mm)

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BLOCK DIAGRAM
CS SK DI DO
Register RDA1 DA1 (8bits) AMP1
Control
RDA2 EEPROM RDA3 Oscillator RVPD RTMP
DA2 (8bits) AMP2
DA3 (8bits) AD1 (8bits) AD2 (8bits) T-SENSE ALMOUT
Com
BIAS
VREF
RINT
Power on Reset RATRM
ALM Timing Gen
AVDD AVSS DVDD DVSS

2
TEMPTEST ALMMOD1 ALM
ASAHI KASEI AK2570 consists of these circuit blocks as below. Circuit block Oscillator VREF Functional description
[AK2570]
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
AD1
AD2
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
DA1, AMP1
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 `H' level 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
DA2, AMP2 DA3, ALMOUT, Comparator, ALM Timing Generator
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 `H' level signal to SHUTDN-pin makes that DAOUT2-pin outputs `0V (min.)'. This block outputs the `H' level 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 x 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.
EEPROM
This circuit temporarily stores the ambient temperature data (in RTMP register), the Register Control Power on Reset 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".

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ASAHI KASEI
[AK2570]
PIN ASSIGNMENT
[1] TEMPTEST [2] BIAS [3] FB1 [4] DAOUT1 [5] FB2 [6] DAOUT2 [7] AVDD [8] AVSS [9] VPDIN [10] ALM
[20] ALMMOD0 [19] ALMMOD1 [18] SHUTDN [17] DVDD [16] DVSS [15] DO [14] DI [13] SK [12] CS [11] ENVIN
AK2570
No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Name TEMPTEST BIAS FB1 DAOUT1 FB2 DAOUT2 AVDD AVSS VPDIN ALM ENVIN CS SK DI DO DVSS DVDD SHUTDN
I/O O O I O I O I I I O I I I I O I I I I I
Type Analog Analog Analog Analog Analog Analog Power Power Analog CMOS CMOS CMOS CMOS CMOS CMOS Power Power CMOS CMOS CMOS
Function Output the voltage generated by the T-SENSE (Factory use) Output the current reference determined by the external resistance Input the feed back voltage to AMP1 for the gain control Output the compensation voltage [1] for the LD Input the feed back voltage to AMP2 for the gain control Output the compensation voltage [2] for the LD Supply the power for the analog part (+3.3V) Ground the analog part (0V) Input the signal of the monitor PD Output the aging alarm Input the envelope signal used at burst transmission Input the Chip Select signal with the serial interface Input the Shift clock with the serial interface Input the Data with the serial interface Output the Data with the serial interface Ground the digital part (0V) Supply the power for the digital part (+3.3V) Input the shut down signal for DA1 and DA2 Input the select signal [1] for the aging alarm mode Input the select signal [0] for the aging alarm mode
AC load DC load Remark
[Note 1]
< 20pF
< 20pF
< 20pF
[Note 2]
< 100pF
See P.15 See P.15 See P.15
19 ALMMOD1 20 ALMMOD0
[Note 1] : Kindly insert the external register 75k (1%) between BIAS-pin and AVSS. [Note 2] : It is necessary to input the `L' level signal to CS-pin at `Power ON'.

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ASAHI KASEI
[AK2570]
FUNCTIONAL DESCRIPTION
1. Explanation for the `mode' AK2570 has the 2 operational modes, "Self-operation mode" and "Training mode". After executing the evaluation and the adjustment for the LD module including AK2570 in "Training mode", it is possible to use AK2570 ordinarily in "Self-operation mode" for compensating the temperature drift of the LD module. "Self-operation mode" is the ordinary operational mode. If the ambient temperature drifts, AK2570 can maintain the emission intensity of the LD module constant by executing the APC operation, i.e. controlling the Bias- and the Modulation- current for the LD module, periodically (the compensation period is about 100msec) in "Self-operation mode". (See p.6) On the other hand, in "Training Mode", it is possible to evaluate and adjust AK2570 and the LD module by the access to the data in the EEPROM and the registers. (See p.7)
[a] Constitution of the mode and the command
Self-operation mode
[Note1] [Note2]
Training mode
Initial setting
Activating internal circuit
Register access
EEPROM access
Command for Self-operation mode Command for Training mode Command for Selecting AD1 Command for Selecting AD2
Command for A/D operation Command for Resetting data in RDA1-3
READ-REG WRITE-REG
EWEN EWDS WRITE-EEP READ-EEP
[Note 1] While operating in "Self-operation mode", it is possible to shift to "Training mode" by executing `Command for Training mode' and this is the only available command. That is to say that any other command is not effective in "Self-operation mode". [Note 2] On the other hand, while operating in "Training mode", it is possible to shift to "Self-operation mode" by executing `Command for Self-operation mode' or forcing the `L' level signal to SK-pin for 50ms more and AK2570 shifts to "Self-operation mode" with behaving as same as the operation at `Power ON'.

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ASAHI KASEI [b] Explanation for the modes and the commands (1) Self-operation mode
[AK2570]
The on-chip `Power on Reset' circuit initializes the data in all registers and sets AK2570 in "Self-operation mode" automatically at `Power ON'. In "Self-operation mode", AK2570 operates as below and keeps the emission intensity of the LD module constant by periodically applying the compensation voltage for the Biasand the Modulation- current against the temperature drift of the LD module. In 50msec after the end of the resetting operation at `Power ON', the data in EEPROM (Address =`1 1111 1111 [EINT memory]') is transferred to RINT and RATRM registers. Notice that the data in these registers can not change except the case of executing `Power ON' again or re-writing the data with executing `WRITE-REG' command in "Training mode'. In "Self-operation mode", the T-SENSE converts the detected ambient temperature to the voltage. AD2 encodes this voltage to the 8bits digital data and transfers this data to RTMP register. This data is converted to the EEPROM address and utilized for reading the temperature characteristic data of the LD retained in the EEPROM. The EEPROM data is transferred to RDA1 ~ RDA3 registers and the output voltage of DA1 ~ DA3 are controlled. It is realized that the constant emission intensity of the LD is independent with the temperature drift by controlling the Bias- and the Modulation- current for the LD module and the alarm signal for the weakened LD. This behavior is executed periodically (the period is about 100ms). While operating in "Self-operation mode", it is impossible to execute any command except `Command for Training mode'.
Power ON
The 'Power on Reset' circuit operates and initializes the data in all registers.
The data for RINT & RATRM registers retained in EEPROM (Address="1 1111 1111") is transferred to REG0 register. The period is about 100ms
The data is transferred from REG0 register to RINT & RATRM registers.
AD2 executes A to D conversion for the output voltage from the T-SENSE. 0.6ms typ
50ms typ
The output data "XXXX XXXX" generated by AD2 is transferred to RTMP register. The access to EEPROM is executed with referring the data held in RTMP register. The data for RDA1~2 registers retained in EEPROM (address = "x xxxx xxx0") is transferred to D31~D16 in REG0 register. The data for RDA3 register retained in EEPROM (address = "x xxxx xxx1") is transferred to D15~D8 in REG0 register. The data in REG0 register is transferred to RDA1 ~ RDA3 registers.
It is waiting for the next compensatory operation. Note) REG0 register : This register synsthesizes the 32bits data and temporarily holds the data when transferring the data from the EEPROM to the registers.

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ASAHI KASEI (2) Training mode
[AK2570]
"Training mode" is used for the evaluation and the adjustment about AK2570. It is possible to write and read the data in the EERPOM and the registers and to execute activating the internal circuit for setting the temperature compensation data with the serial interface. Notice that it is possible to shift to "Training mode" by executing `Command for Training mode' and any other command is not available while operating in "Self-operation mode". After executing `Command for Training mode', it is necessary to input the clock or the `H' level signal to SK-pin continuously to keep the operational mode is in "Training mode". It is able to return to "Selfoperational mode" by forcing the `L' level signal to SK-pin for 50msec more in "Training mode". In "Training mode", the periodical operation of temperature compensation for the LD is stopped. Also at the time of executing `Command for Training mode' while operating in "Self-operational mode", AK2570 transfers to "Training mode" after completing the periodical operation. Recommended sequence in "Training mode
START Set the temperature at the minimum value for the use (e.g. -40 ) Execute 'Command for Training mode'
--> Initial setting : Command for Training mode
Write '00000' in RINT register --> Register access : WRITE-REG(RINT)
Add '+1' to the data in RINT register
--> Register access WRITE-REG(RINT)
AD2 executes A to D conversion --> Initial Setting : Command for Selecting AD2 --> Activating Internal Circuit : for the T-SENSE output
Command for A/D operation
N
Confirm the code generated by AD2 is '00000010'~'00001000' (e.g. -40 ) Y
(See p.15)
--> Register Access : READ-REG(RTMP)
Set the data for DA1 & DA2 that will be retained in EDA1 &EDA2 to fit the LD characteristics Change the ambient temperature
--> Register access : READ-REG(RTMP)
--> Register Access : WRITE-REG(RDA1) --> Register Access : WRITE-REG(RDA2) --> Evaluation for the LD characteristics --> Adjusting the monitoring PD --> Initial Setting : Command for Selecting AD1 --> Activating Internal Circuit : Command for A/D operation --> Register Access : READ-REG(RVPD)
After execting the A to D conversion in AD1 for the input voltage to VPDIN-pin, read the data in RVPD register that will be retained in EDA3 Complete the measurement for the compensation data Y Make the data for writing in the EEPROM Write the compensatory data in the EEPROM FINISH
N
--> EEPROM Access : EWEN --> EEPROM Access : WRITE-EEP

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ASAHI KASEI I) Initial Setting [1] Command for Self-operation mode
[AK2570]
By executing `Command for Self-operation mode', it is possible to transfer the mode from "Training mode" to "Self-operation mode". [2] Command for Training mode By executing `Command for Training mode', it is possible to transfer the mode from "Self-operation mode" to "Training mode". Also any command except `Command for Training mode' is not available while AK2570 operates in "Self-operation mode". [3] Command for Selecting AD1 `Command for selecting AD1' is available in "Training mode". This command sets that AD1 (the A to D converter for the input voltage to VPDIN-pin) is enable for the operation and the selector between AD1 and RVPD register is available. After this command is performed, the 8bits digital data of the VPDIN-pin signal encoded in AD1 is stored in RVPD register by executing `Activating internal circuit - Command for A/D operation'. [4] Command for Selecting AD2 `Command for selecting AD2' is available in "Training mode". This command sets that AD2 (the A to D converter for the output voltage from T-SENSE) is enable for the operation and the selector between AD2 and RTMP register is available. After this command is performed, the 8bits digital data of the T-SENSE output encoded in AD2 is stored in RTMP register by executing `Activating internal circuit - Command for A/D operation'. II) Activating internal circuit [1] Command for A/D operation `Command for A/D operation' makes that the selected A to D converter (AD1 or AD2) operates and the selected register (RVPD register or RTMP register) stores the data generated in the A to D converter selected by executing `Command for Selecting AD1' or `Command for Selecting AD2'. Also this command makes only that the selected register stores the 8bits digital data generated by the selected A to D converter. [2] Command for Resetting data in RDA1-3 `Command for Resetting data in RDA1-3' sets that RDA1 ~ RDA3 registers hold the data retained in EEPROM which address is nominated by the data in RTMP register. Also this command is always available in "Training mode" and independent with the selector set by `Command for Selecting AD1' or `Command for Selecting AD2'.
III) Register Access [1] Command for reading the data in the register (READ-REG It is able to read the data held in the nominated register by executing `READ-REG' command. [2] Command for Writing the data in the register (WRITE-REG) It is able to write the data in the nominated register by executing `WRITE-REG' command. 8 2001/10
ASAHI KASEI Register map
Name RTMP RDA1 RDA2 RDA3 RINT RVPD RATRM Address 000 001 010 011 100 101 110 Data D23 ~ D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X X X X ~ X D7 D6 D5 D4 D3 D2 D1 D0 ~ X D7 D6 D5 D4 D3 D2 D1 D0 ~ X D7 D6 D5 D4 D3 D2 D1 D0 ~ X X X X D4 D3 D2 D1 D0 ~ X D7 D6 D5 D4 D3 D2 D1 D0 ~ X X X X D4 D3 D2 D1 D0 Function
[AK2570]
~ X D7 D6 D5 D4 D3 D2 D1 D0 Holding the data (temperature) generated by AD2 Holding the data for DA1 Holding the data for DA2 Holding the data for DA3 Holding the trimming data for T-SENSE [*1] Holding the data (VPDIN) generated by AD1 Holding the trimming data for ALMOUT [*2]
[*1 RINT register stores the initial data for the offset voltage of the T-SENSE [*2] ATRM register stores the adjustment data for the alarm timing at the 50Mbps and the 156Mbps burst transmission (AKM recommends to use the EEPROM data for RATRM register already written at the shipment.
Initial register data
Name RTMP RDA1 RDA2 RDA3 RINT RVPD RATRM Address 000 001 010 011 100 101 110 D23 X X X X X X X ~ ~ ~ ~ ~ ~ ~ ~ D8 X X X X X X X D7 1 0 0 0 X 0 X D6 1 0 0 0 X 0 X D5 1 0 0 0 X 0 X D4 1 0 0 0 0 0 1 D3 1 0 0 0 0 0 0 D2 1 0 0 0 0 0 0 D1 1 0 0 0 0 0 0 D0 1 0 0 0 0 0 0
`X' is indefinite, `1' or `0'.
IV) EEPROM Access [1] Command for enabling to write the data in the EEPROM (EWEN) `EWEN' command makes it possible to write the data in the EEPROM. It is necessary to execute this command before writing the data in the EEPROM, because it is automatically set at `Power ON' to prohibit writing the data in the EEPROM. In "Training mode", it is always possible to write the data in the EEPROM after executing this command except the case of `Power OFF' or executing `EWDS' command. [2] Command for prohibiting to write the data in the EEPROM (EWDS) `EWDS' command makes it impossible to write the data in the EEPROM and it is the same setting at `Power ON'. This command is available to change the setting to prohibit writing the data in the EEPROM without `Power OFF'. [3] Command for writing the data in the EEPROM (WRITE-EEP) It is able to write the data in the nominated EEPROM by executing `WRITE-EEP' command. And it is necessary to execute `EWEN' command at first for permitting to write the data in the EEPROM. [4] Command for reading the data in the EEPROM (READ-EEP) It is able to read the data held in the nominated EEPROM by executing `READ-EEP' command.

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ASAHI KASEI EEPROM map
Name EDA12 EDA3 EDA12 EDA3 | EDA12 EDA3 ERES EINT Address A8 - A0 0 0000 0000 0 0000 0001 0 0000 0010 0 0000 0011 | 1 1111 1100 1 1111 1101 1 1111 1110 1 1111 1111 The unused bits (3bit) The data for RDA1 (8bit) The data for RDA3 (8bit) The data for RDA1 (8bit) The data for RDA3 (8bit) | The data for RDA1 (8bit) The data for RDA3 (8bit) Data D15 D14 D13 D12 D11 D10 D9 D8 D7 D6
[AK2570]
D5 D4 D3 D2 D1 D0
The data for RDA2 (8bit) The unused bits (8bit) The data for RDA2 (8bit) The unused bits (8bit) | The data for RDA2 (8bit) The unused bits (8bit)
The reserved bits (16bit) The data for RATRM The unused bits The data for RINT D12 - D8(5bit) (3bit) D4 - D0 (5bit)
AKM cannot assure the period of the data retention (10years [min.] at 85C) for `The unused bits'. Kindly pay attention when writing the data for RINT, because EINT also retains the data for RATRM register written at AKM.
2 Serial Interface In "Training mode", it is able to execute the access to the EEPROM and the registers and to input the operational command for AK2570 with the 32bits serial data via 4pins consist of CS(#12), SK(#13), DI(#14) and DO(#15). 1) Constitution of the serial interface data [a] "Initial setting", "Activating Internal Circuit" and "Register Access" (total 32bits)
Classification 4bits Selection 1bit Address 3bits Data 24bits
[b] "EEPROM Access" (Total 32bits)
Classification 4bits Command 2bits Address 10bits Data 16bits
These bits contain the arbitrary bit (the data is not definite, `0' or `1')'. Please refer to the table in the next page.

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ii) Access to the serial interface
Classification 1 1 0 0 Select 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 1 1 1 0 0 1 1 1 1 1 1 1 0 1 1 0 1 0 0 1 Classification [4]EEPROM Access [3]Register Access [2]Activating Internal Circuit [1]Initial Setting Address 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 1 1 1 0 0 1 0 0 0 1 1 0 0 0 0 1 1 0 0 1 0 0 1 1 0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 0 1 0 1 0 1 0 0 1 x x x x x x x x x x x x x x x x x x x x 0 1 x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x Data x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x
x D7 D6 D5 D4 D3 x D7 D6 D5 D4 D3 x D7 D6 D5 D4 D3 x D7 D6 D5 D4 D3 x x x x x x x D4 D3 x D4 D3 x D7 D6 D5 D4 D3 x D7 D6 D5 D4 D3 x D7 D6 D5 D4 D3 x D7 D6 D5 D4 D3 x D7 D6 D5 D4 D3 x x x x x x x x x x x x x D4 D3 x D4 D3 x x x x x x x D7 D6 D5 D4 D3
x A8 A7 A6 A5 A4 A3 A2 A1 A0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 x A8 A7 A6 A5 A4 A3 A2 A1 A0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 Address Data
Command
Note) `x' in this table is not definite, `0' or `1'.

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[AK2570]
III) Timing for the serial interface [1] Initial Setting
CS SK 0 DI 1 1 1 2 0 3 0 4 1 5 A2 A2 0 0 0 0 6 A1 A1 0 0 1 1 7 A0 A0 0 1 0 1 8 X 9 X 10 X 30 X 31 X
---------
Command for Self-operation mode Command for Training mode Command for Selecting AD2 Command for Selecting AD1
[2] Activating Internal Circuit
[a] Command for A/D operation CS SK 0 DI 1 1 1 2 1 3 1 4 1 5 0 6 0 7 0 8 X 9 X 10 X 30 X 31 X
[b] Command for Resetting data in RDA1-3 CS SK 0 DI 1 1 1 2 1 3 1 4 1 5 0 6 0 7 1 8 X 60 X 61 X 62 X 63 X
In the case of executing `Command for Resetting data in RDA1-3', it is necessary to input the 64 clocks to SK-pin with keeping to force the `H' level signal to CS-pin.
[3] Register Access
[a] Command for reading the data in register(READ-REG) CS SK 0 DI DO 1 1 1 2 1 3 0 4 5 6 7 8 9 10 20 21 22 23 24 25 26 27 28 29 30 31
0 A2 A1 A0 Don't care ('0' or '1') D7 D6 D5 D4 D3 D2 D1 D0 Hi-Z
Hi-Z

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[b] Command for writing the data in the register (WRITE-REG) CS SK 0 DI 1 1 1 2 1 3 0 4 5 6 7 8 9 10
[AK2570]
20 21 22 23 24 25 26 27 28 29 30
31
1 A2 A1 A0 X X X A2 0 0 0 0 1 1 1 A1 0 0 1 1 0 0 1 A0 0 1 0 1 0 1 0
X X X X D7 D6 D5 D4 D3 D2 D1 D0 Data 8bits 8bits 8bits 8bits 5bits 8bits 5bits
---------------
Register RTMP RDA1 RDA2 RDA3 RINT RVPD RATRM
= = = = = = =
[4] EEPROM Access
[a] Command for enabling/prohibiting to write the data in the EEPROM (EWEN/EWDS) CS SK 0 DI 1 1 1 2 0 3 1 4 0 5 6 7 8 9 10 20 21 22 23 24 25 26 27 28 29 30 31 XXXXXXXXXXXX
0 A9 A8 A7 X X
A9 A8 A7 0 0 0 --- EWDS command 1 1 1 --- EWEN command
[b] Command for writing the data in the EEPROM (WRITE-EEP) CS SK 0 DI DO 1 1 1 2 0 3 1 4 0 5 1 6 7 8 9 10 14 15 16 17 18 A1 A0 D15 D14 D13 28 29 30 31 D3 D2 D1 D0
X A8 A7 A6 A5 Hi-Z
tE/W
[c] Command for reading the data in the EEPROM (READ-EEP) CS SK 0 DI DO 1 1 1 2 0 3 1 4 1 5 0 6 7 8 9 10 14 15 16 17 18 A1 A0
D15 D14 D13
28 29 30 31
X A8 A7 A6 A5 H-Z
D3 D2 D1 D0 Hi-Z

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ASAHI KASEI 3. Thermo-sensor (T-SENSE)
[AK2570]
Kindly see the figure below that shows the relationship between the detected ambient temperature (T) and the generated output voltage (VT) in the T-SENSE.
Encoded data in AD2 0000 0000 0000 0001 0000 0010 0000 0011
Output voltage VT [V] 2.2 Offset voltage
0111 1111 1000 0000 1000 0001
1111 1100 1111 1101 1111 1110 1111 1111 -->1111 1110 Note
0.0 -40 +85 Ambient temperature T[C]
[Note] In `Self-operation mode', it is the unique case that the data "1111 1111" generated by AD2 is converted to "1111 11110" automatically and the EEPROM data in the address `1 1111 110X' is used as the compensation data, this is the reason why that the EEPROM which address is "1 1111 111X" retains the reserved data and the trimming data for the T-SENSE and the ALMOUT. VT is 2.2V (Typ.) at -40C and 0.0V at 85C above and has the distribution due to each LSI. However it is possible to cancel the distributed offset voltage arising in the T-SENSE among LSIs by setting the data (D4 ~D0) in RINT register. The offset cancel voltage (Reference) corresponding to the data (D4 ~D0) in RINT register is shown in the table below. RINT register D4 D3 D2 D1 D0 11111 11110 11101 11100 | 10001 10000 01111 | 00011 00010 00001 00000 Offset cancel voltage [mV] (Reference +375 +350 +325 +300 | +25 0 -25 | -325 -350 -375 -400

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ASAHI KASEI *Set up for the RINT register
[AK2570]
The offset voltage arising in the T-SENSE is slightly different and has the distribution among the LSIs. Please adjust that the data in RTMP register exists between the `Minimum code' and the `Maximum code' shown in this table at the `Minimum ambient temperature for the use' with writing the data in RINT register in "Training mode", and refer to `Recommended sequence in "Training mode" in p.7. Minimum ambient temperature for the use 0C -20C -30C -40C In the case of fitting at +25C(Reference) Minimum code 01000010 00100010 00010010 00000010 01100110 Maximum code 01001000 00101000 00011000 00001000 01101100
1LSB of AD2 output data (8bits) is 8.63mV (Typ.. Therefore 6codes is 51.8mV (Typ.) corresponding to the range between `Minimum code' and `Maximum code' shown in above table. On the other hand, the step of the offset cancel voltage is 25mV (Typ.) and it is possible to adjust the output voltage of the T-SNESE in the range of `Minimum code' and `Maximum code'. After this offset voltage adjustment, the output voltage from the T-SENSE becomes appropriate for the AD2 input range at every ambient temperature (-40C ~ +85C). Also the `Minimum code' and the `Maximum code' for this adjustment increase 16 codes/10C.
4. D to A converter (DA1 and DA2) In the normal operation, forcing the `L' level signal to SHUTDN-pin makes that DAOUT1 (the output of DA1 +AMP1) and DAOUT2 (the output of DA2+AMP2) utput the voltage corresponding to the data in RDA1 and RDA2 registers. On the other hand, forcing the `H' level signal to SHUTDN-pin makes that DAOUT1 and DAOUT2 output 0V (Min.). Also the data in RDA1 and RDA2 registers does not change and is held while forcing `Shut down signal (the `H' level)'. By forcing the `L' level signal to SHUTDN-pin again, DAOUT1 and DAOUT2 output the signal corresponding the continuously held data in RDA1 and RDA2 registers.
5. Alarm circuit (DA3, ALMOUT, Comparator and ALM Timing Generator) I) Mode setting The alarm circuit has the 3 modes (the Continuous mode, the 156Mbps burst transmission mode and the 50Mbps burst transmission mode). Each mode is set by the signals forced to ALMMOD0-pin and ALMMOD1-pin. ALMMOD1 0 0 1 1 ALMMOD0 0 1 0 1 Mode the Continuous mode the 50Mbps burst transmission mode the 156Mbps burst transmission mode Prohibited

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ASAHI KASEI II) Continuous mode
[AK2570]
The alarm circuit compares the input voltage to VPDIN-pin (the monitoring PD signal) and the output voltage from DA3 (the alarm threshold level). The data for the alarm threshold level is retained in the EEPROM (EDA3), transferred to RDA3 and converted D to A signal in DA3. At any time, the `H' level alarm signal can be generated and outputted from ALM-pin in the case that the input voltage to VPDIN-pin becomes lower than the output voltage of DA3.
III) 50Mbps burst transmission mode and 156Mbps burst transmission mode The alarm circuit compares the input voltage to VPDIN-pin (the monitoring PD signal) and the output voltage from DA3 (the alarm threshold level). The data for the alarm threshold level is retained in the EEPROM (EDA3), transferred to RDA3 and converted D to A signal in DA3. The alarm circuit detects the polarity of the input signal to ENVIN-pin at the constant timing (the detecting point) from the rising edge (`L'a'H') of this signal. The alarm circuit outputs the alarm signal (the `H' level) from ALM-pin in the case that the input voltage to VPDIN-pin is lower than the output voltage from DA3 and ENVIN signal is still kept at the `H' level. Also the alarm circuit detects the rising edge of the ENVIN signal and fixes the constant timing to output the alarm signal. In the case that VPDIN signal recovers and becomes higher than the alarm threshold level at the detecting point with ENVIN = `H' or that the ENVIN signal becomes the `L' level, the alarm circuit outputs the `L' level (the normal signal) from ALM-pin.
* In the case of outputting the alarm signal continuously
ENVIN ALM
The fixed timing of outputting the alarm signal
* In the case of stopping the alarm signal (the VPDIN signal recovers)
ENVIN ALM
The fixed timing of outputting the alarm signal
The VPDIN signal recovers

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ASAHI KASEI
[AK2570]
ABSOLUTE MAXIMUM RATING
Parameter Power supply voltage Ground level Digital input voltage Analog input voltage Input current Storage temperature Symbol VDD VSS VDIN VAIN IIN TSTG Min. -0.3 0.0 -0.3 -0.3 -10 -55 Max. 6.0 0.0 VDD+0.3 VDD+0.3 10 +125 Unit V V V V mA C Except the pins above Remark DVDD-pin, AVDD-pin DVSS-pin, AVSS-pin
AK2570 may operate abnormally and be broken under the condition exceeding the range shown above.
RECOMMENDED OPERATING CONDITION
AKM can assure the characteristics of AK2570 specified in this data sheet under the condition as below. Parameter Power supply voltage Ambient temperature for operation Symbol VDD VSS Ta Min. 2.97 0.0 -40 Typ. 3.30 0.0 Max. 3.63 0.0 85 Unit V V C Remark

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ASAHI KASEI
[AK2570]
ELECTRICAL CHARACTERISTICS
(1) Power Consumption Parameter Consumptive current Symbol IDD Min. Typ. Max. 30 Unit mA Remark
The consumptive current which does not include the driving current for the outputs is measured under the condition that the digital input pins are connected to VSS or VDD.
(2) EEPROM characteristics Parameter EEPROM total writing times EEPROM data retention 1 EEPROM data retention 2 (3) Digital Part [a] DC characteristics Parameter Input higher voltage Input lower voltage Input higher current Input lower current Output higher voltage Output lower voltage [b] AC characteristics Parameter SK : Period SK : Pulse duty Delay time : CS=`H' to SK=`H'[*] Delay time : SK=`L' to CS=`L' Time for setting up the data Time for holding the data Delay time for the output Time to write in the EEPROM CS : Minimum time in the `L' level Delay time : CS=`L' to DO=`Hi-Z' Symbol tSKP tSKP tSKW tCSS tCSH tDIS tDIH tPD tE/W tCS tOZ CL = 100pF 10 250 100 Condition While A/D conversion While other operation Min. 10 2 40 150 0 200 200 1 60 Typ. Max. Unit s s % ns ns ns ns s ms ns ns Symbol VIH VIL IIH IIL VOH VOL VIH = VDD VIL = 0V IOH = -0.2mA IOL = 0.2mA -10 0.9VDD 0.1VDD Condition Min. 0.7VDD VSS Typ. Max. VDD 0.3VDD 10 Unit V V A A V V Min. 10000 10 300 Typ. Max. Unit time year year 85C 50C (Reference) Remark
[*] It is necessary to force the `L' level to SK-pin at the rising edge of the CS signal and to apply the clock to SK-pin at 150msec or more after this rising edge of the CS signal.

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ASAHI KASEI Digital Part -AC characteristics : Timing [1] Timing for the command input
CS
tCSS tSKW tSKW tSKP
[AK2570]
SK
DI
tDIS tDIH High-Z
DO
[2] Timing for the data output
CS
tCSH
SK
DI
tPD tPD D2 D1 tPD tOZ D0 High-Z
DO
D3
[3] Timing for writing the data in the EEPROM
tCS
CS
tCSH
SK
tDIS tDIH D1 D0
DI
High-Z
tE/W
DO

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ASAHI KASEI (4) Analog part [a] Input characteristics of the A to D converter <1> AD1 Resolution Conversion time DNL Input range 1 (Peak voltage) MSB D7 1 1 D6 D5 D4 D3 D2 D1 1 1 1 1 1 1 1 1 1 1 1 1 8bits linear About 150s or 15 SK clocks 2LSB 0.0V ~ 1.0V [Typ] LSB D0 1 0 a 1.0V Input voltage
[AK2570]
(Straight binary) 0 0 <2> AD2 Resolution Conversion time DNL Input range 2 (Temperature) MSB D7 0 0 D6 D5 D4 D3 D2 D1 0 0 0 0 0 0 0 0 0 0 0 0 8bits linear About 150s or 15 SK clocks 0.7LSB 0.0V ~ 2.2V [Typ.] LSB D0 0 1 Input voltage (Detected temperature) a 2.2V (-40C) 0 0 0 0 0 0 0 0 0 0 0 0 1 0 a 0.0V
(Straight binary) 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 0 a 0.0V (> 85C)
[b] Output characteristics of the A to D converter <1> DA1, DA2 Parameter Resolution DNL Maximum output voltage Minimum output voltage Output voltage at the shut down operation Output current
and the ambient temperature.
Min. -1/2 0.425 0.0 0.000 2.50
Typ. 8
Max. +1/2
Unit bit LSB V mV
Remark Circuit design 15%
0.500
0.575 10.0 5.000
mV SHUTDN-pin is forced `H' mA Input code =181 (dec)
included in the range 5% 15% is the distribution caused by the fluctuations of the power source voltage

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ASAHI KASEI <2> The over shoot voltage of DA1 and DA2 at relieving the shut down operation Input data for DA1 and DA2 11111111 11111110 | 00001001 00001000 00000111 00000110 | 00000001 00000000 <3> DA3 Min. Resolution Voltage step by 1 code Maximum output voltage Minimum output voltage Typ. 8 3.92 1.00 0.00 Max. Unit bit mV V mV Remark Circuit design 13.0 (Stabilized in 120s) mV `Output voltage'x1.2 mV Min. Typ. Max. Unit
[AK2570]
Remark
Designed guarantee value
Designed guarantee value
Designed guarantee value Designed guarantee value Designed guarantee value
<4> Relationship between the input digital code and the output voltage D to A converter Digital code Output voltage (Typ.) 11111111 500mV DA1 | 00000001 00000000 11111111 DA2 | 00000001 00000000 11111111 DA3 | 00000001 00000000 | 1.96mV 0.0V 500mV | 1.96mV 0.0V 1.0V | 3.92mV 0.0V

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ASAHI KASEI [c] Output characteristics of the alarm signal <1> Continuous mode Parameter Delay time of ALM signal Symbol tDLY Condition DA3 output=0.5V VPDIN=2.0Va0V Min. Typ. Max. 100
[AK2570]
units ns
VPDIN tDLY ALM
DA3 output
<2> 50Mbps burst transmission mode Parameter Start time for detecting ENV signal Total time for detecting ENV signal Time for detecting ENV signal Time for confirming VPDIN signal Time for outputting ALM signal Symbol tENVDT1 tENVDT2 tENVDT tVIN tALMO CL=20pF 463.0 212.2 771.6 Condition Min. 463.0 617.3 154.3 Typ. Max. unit ns ns ns ns ns
[*] The condition of measuring for the `Time for outputting ALM signal' is that the input voltage to VPDIN-pin is 0.0V (constant).
CLK
(51.84MHz)
tENVDT2 tENVDT1 ENVIN tVIN VPDIN tALMO ALM tENVDT
The clock (51.84MHz) is not applied to AK2570. <3> 156Mbps burst transmission mode Parameter Start time for detecting ENV signal Total time for detecting ENV signal Time for detecting ENV signal Time for confirming VPDIN signal Time for outputting ALM signal Symbol tENVDT1 tENVDT2 tENVDT tVIN tALMO CL=20pF 167.2 64.3 372.9 Condition Min. 167.2 218.8 51.4 Typ. Max. unit ns ns ns ns ns
[*]The condition of measuring for the `Time for outputting ALM signal' is that the input voltage to

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ASAHI KASEI
VPDIN-pin is 0.0V (constant).
[AK2570]
CLK
(155.52MHz)
tENVDT2 tENVDT1 ENVIN tVIN VPDIN tALMO ALM tENVDT
The clock (155.52MHz) is not applied to AK2570.
Delay time between the falling edge of ENVIN and that of ALM In the 50Mbps burst transmission mode and the 156Mbps burst transmission mode, the ALM signal becomes the `L' level in the case of that the ALM signal is still generated (at the `H' level) and the `L' level signal is forced to ENVIN-pin (ENV signal). There is the delay time between the falling edge of the ENV signal and that of the ALM signal in this case.
Parameter Delay time between the falling edge of ENVIN and that of ALM
Symbol tALMDL
Condition CL=20pF
Min.
Typ.
Max. 19.3
unit ns
ENVIN ALM
tALMDL
Error on the judgment for ALM signal There is some error on the judgment for generating the alarm signal. Therefore ALM signal will be often generated in the case that the input voltage to VPDIN-pin is slightly bigger than the DA3 output (the alarm threshold level). The error shown below is the value against the DA3 output. DA3 output (Typ.) 58.8mV 98.0mV Error on the judgment for ALM signal [*] 3dB 2dB [*] dB = the converted value for the power Remarks Designed reference value Designed reference value

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ASAHI KASEI
[AK2570]
RECOMMENDED EXTERNAL CIRCUIT
[1] BIAS-pin for the reference voltage Kindly connect the resistance (the accuracy) between BIAS-pin and AVSS with the line pattern as short 1% as possible.
AK2570
R=75k 1 BIAS(#2) AVSS
[2] Power pins Kindly insert the capacitor as shown below between DVDD-DVSS and AVDD-AVSS.
AK2570
AVDD(#7) [DVDD(#17)] C=0.1 F AVSS(#8) [DVSS(#16)]

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ASAHI KASEI
[AK2570]
EXAMPLE for EXTERNAL CIRCUIT
[a] The examples of the external circuit for DAOUT1-pin / FB1-pin and DAOUT2-pin / FB2-pin are shown below in the case of the use at the direct variation for the LD. <1> Example [1]
AK2570
LD DAOUT1(#4)
FB1(#3) Driver Circuit DAOUT2(#6)
FB2(#5)
<2> Example [2]
AK2570
LD DAOUT1(#4)
FB1(#3) DAOUT2(#6)
Voltage for the Bias current Driver LSI Voltage for the Modulation current
FB2(#5)
[b] The example of the external circuit for VPDIN-pin is shown below.
AK2570
PD VPDIN(#9)

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ASAHI KASEI
[AK2570]
PACKAGE
Package type : 20pin - SSOP
Marking on the surface of the package : (1) Index : Indicating Pin #1 (2) Company name : AKM (3) Product No. : AK2570 (4) Date code : XXXXXXX (7 figures)
Package size :
7.2TYP
20
11
AK2570
xxxxxxx
10 0.13 0.32 0.10 0.10 0.10
M
1
0.65
2.10MAX
0 ~ 10
0.10

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7.90 0.20
5.3TYP
AKM
0.6 0.2
7.4MAX
0.22 0.05
ASAHI KASEI
[AK2570]
IMPORTANT NOTICE * These products and their specifications are subject to change without notice. Before considering any use or application, consult the Asahi Kasei Microsystems Co., Ltd. (AKM) sales office or authorized distributor concerning their current status. * AKM assumes no liability for infringement of any patent, intellectual property, or other right in the application or use of any i nformation contained herein. * Any export of these products, or devices or systems containing them, may require an export license or other official approval under the law and regulations of the country of export pertaining to customs and tariffs, currency exchange, or strategic materials. * AKM products are neither intended nor authorized for use as critical components in any safety, life support, or other hazard related device or system, and AKM assumes no responsibility relating to any such use, except with the express written consent of the Representative Director of AKM. As used here: (a) A hazard related device or system is one designed or intended for life support or maintenance of safety or for applications in medicine, aerospace, nuclear energy, or other fields, in which its failure to function or perform may reasonably be expected to result in loss of life or in significant injury or damage to person or property. (b) A critical component is one whose failure to function or perform may reasonably be expected to result, whether directly or indirectly, in the loss of the safety or effectiveness of the device or system containing it, and which must therefore meet very high standards of performance and reliability. * It is the responsibility of the buyer or distributor of an AKM product who distributes, disposes of, or otherwise places the product with a third party to notify that party in advance of the above content and conditions, and the buyer or distributor agrees to assume any and all responsibility and liability for and hold AKM harmless from any and all claims arising from the use of said product in the absence of such notification.

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