AK9824M

ASAHI KASEI [AK9822/24] AK9822 / 24 2K / 4Kbit EEPROM with 2ch 8bit D/A Converter General Description The AK9822/24 includes 2 channel, 8 bit D/A converters with on-chip output buffer amps and it is capable to store the input digital data of each D/A converter by on-chip non-volatile CMOS EEPROM. The AK9822/24 is optimally designed for various circuit adjustments for consumer and industrial equipments and it is ideally suited for replacing mechanical trimmers. Feature † EEPROM section AK9822 • • • 128 words Õ 16bit AK9824 • • • 256 words Õ 16bit One chip microcomputer interface Sequential register read † D/A Converter section 2 channel Resolution : 8bit Differential Non-Linearity : ‘1.0 LSB Linearity Error : ‘1.5 LSB Output Voltage Range : GND ∼ VCC † Wide VCC operation • EEPROM section : 1.8V∼5.5V • D/A Converter Section : 2.7V∼5.5V † Power Down Function Block Diagram DAD01E-00 1999/05 -1- ASAHI KASEI [AK9822/24] „ Ordering Guide AK9822M AK9824M -40°C∼+85°C -40°C∼+85°C 8pin SSOP 8pin SSOP „ Pin Layout „ Pin Description No. Pin Name I/O Function 1 AO1 O Analog Output Pin 2 CS I Chip Select Pin (Schmitt-trigger input) 3 SK I Serial Clock Pin (Schmitt-trigger input) 4 DO O Serial Data Output Pin 5 GND - Ground Pin 6 DI I Serial Data Input Pin 7 VCC - Power Supply 8 AO0 O Analog Output Pin DAD01E-00 1999/05 -2- ASAHI KASEI [AK9822/24] Functional Description The AK9822/24 is composed of EEPROM and the 8bit D/A converter of two channels with the output buffer amplifier. The AK9822/24 can connect to the serial communication port of popular one chip microcomputer directly (3 line negative clock synchronous interface). The AK9822/24 takes the data of the DI pin by the rising edge of the SK pin and outputs the data from the DO pin by the falling edge of the SK pin. The AK9822/24 has 7 instructions such as READ, WRITE, WREN, WRDS, PDEN, PDDS and CALL. The AK9822/24 is operated by inputting these instructions from the serial interface. Each instruction is organized by op-code block (8bits), address block (8bits) and data (8bitsÕ2). The DO pin is "Hi-Z" state except that the DO pin outputs the data of the internal register and the status of Ready/Busy. „ WRITE protection function There are two states such as the WRITE enable state and the WRITE disable state in the AK9822/24. In the WRITE disable state the WRITE instruction becomes invalid and is not executed. When Vcc is applied to the part, the part powers up in the WRITE disable state and the part becomes the WRITE enable state by inputting the WREN instruction. The WRITE enable state continues until the WRDS instruction is executed or Vcc is removed from the part. Execution of a READ instruction is independent of both WREN and WRDS instructions. „ Power down function There are two modes such as the power down mode and the normal mode in the AK9822/24. When the AK9822/24 is in the power down mode, the D/A converter section is in the standby state. At this time, the outputs of the D/A converters become "Hi-Z". When Vcc is applied to the part, the AK9822/24 is in the power down mode. When a AUTO READ function is executed, the part becomes the normal mode. After the AUTO READ function is executed, the mode of the part can be switched by the PDEN and PDDS instructions. The AK9822/24 becomes the power down mode by inputting the PDEN instruction. The part is in the power down mode until the PDDS instruction is executed. When the PDDS instruction is executed, the part becomes the normal mode. When returning to the normal mode from the power down mode, the D/A converters output the voltage value set before entering the power down mode. The relation between the D/A converter state and the mode are shown in the table 1. Mode State of D/A converter Power down mode standby Normal mode normal Table 1. The relation between the state of D/A converter and the mode DAD01E-00 1999/05 -3- ASAHI KASEI [AK9822/24] „ Output of D/A converter The output of the D/A converters can be set by the WRITE and the CALL instructions. Upper 8bit data (D15∼D8) of the first address of the internal EEPROM (the address "0") corresponds to "AO" of the D/A converter output. Lower 8bit data (D7∼D0) of the address "0" corresponds to "A1". The internal composition of EEPROM is shown in the table2. Address D15∼D8 D7∼D0 0 Set data of A0 Set data of A1 1 General purpose memory 127(AK9822) /255(AK9824) General purpose memory Table2. Internal composition of EEPROM If the WRITE instruction by which the address "0" is specified is executed at the normal mode, the outputs of the D/A converter of A0 and A1 are set by the specified data. When the WRITE instruction by which the address "0" is specified is executed at the WRITE enable state and the normal mode, the data is written in the address "0" of EEPROM and the outputs of the D/A converter are set. When the WRITE instruction by which the address "0" is specified is executed at the WRITE disable state and the normal mode, the data is not written in EEPROM and the outputs of the D/A converter are set. Table3 shows the relation between EEPROM, D/A converter and WRITE instruction. State of AK9822/24 Power down mode Normal mode State of address"0" WRITE enable The data change to the specified data. WRITE disable The data does not change. WRITE enable The data change to the specified data. WRITE disable The data does not change. Output of A0 and A1 The DAC outputs are "Hi-Z". The DAC outputs change to the specified data. Table3. Relation between EEPROM, D/A converter and WRITE instruction If the CALL instruction is executed, the outputs of the D/A converter are set by the data of the general purpose memory (AK9822:address "1" -"127", AK9824:address "1" -"255"). The CALL instruction is composed by the op-code and the address. When the CALL instruction is executed at the normal mode, the D/A converter output of A0 is set by the upper 8bit data (D15∼D8) of the specified address and the output of A1 is set by the lower 8bit data (D7∼D0). The CALL instruction is not executed at the power down mode. DAD01E-00 1999/05 -4- ASAHI KASEI [AK9822/24] „ AUTO READ function AUTO READ function automatically reads the content of EEPROM and sets the output of the D/A converter of two channels, when Vcc is applied to the part. When Vcc is applied to the part in CS="L", the AUTO READ function starts by falling CS pin first. After the CS pin is made a low level, the output of AO0 and AO1 is set within 2ms. At this time, the input pins (SK, DI) other than the CS pin are not accepted, and the serial data is not output from the DO pin. If the WREN instruction is executed after the AUTO READ function finished, AK9822/24 becomes the WRITE enable state. After Vcc is applied to the part, the AUTO READ function is executed only once. AUTO READ function is executed when Vcc is applied to the part in CS="L". (note) Because AK9822/24 always executes the AUTO READ function first after Vcc is applied to the part, AK9822/24 is not able to accept the instruction for the first period of "L" of the CS. „ Instruction and Composition of the data Each instruction consist of op-code, address, and data (8bitÕ2) composed in each 8bit. The composition of the WRITE instruction is shown as follows. DAD01E-00 1999/05 -5- ASAHI KASEI [AK9822/24] Instruction Set The AK9822/24 has 7 instructions such as READ, WRITE, WREN, WRDS, PDEN, PDDS, CALL. Each instruction consists of Op-code, address and data. The instruction set is shown in the table4 and table5. When the instructions are executed consecutively, the CS pin should be brought to a high level for a minimum of tCS between consecutive instruction cycle. Instruction READ WRITE WREN WRDS PDEN PDDS CALL TEST Op-code Address 10101000 10100100 10100011 10100000 10101100 10100110 10100010 10101111 A6 A5 A4 A3 A2 A1 A0 0 A6 A5 A4 A3 A2 A1 A0 0 * * * * * * * * * * * * * * * * * * * * Data * * * * * * * * * * * * A6 A5 A4 A3 A2 A1 A0 0 * * * * * * * * D15∼D0 D15∼D0 *∼ *∼ *∼ *∼ *∼ *∼ (note) User can't use this instruction. Table4. Instruction set for AK9822 Instruction READ WRITE WREN WRDS PDEN PDDS CALL TEST Op-code 10101000 10100100 10100011 10100000 10101100 10100110 10100010 10101111 Address Data A7 A6 A5 A4 A3 A2 A1 A0 A7 A6 A5 A4 A3 A2 A1 A0 A7 A6 A5 A4 A3 A2 A1 A0 D15∼D0 D15∼D0 *∼ *∼ *∼ *∼ *∼ * * * * * * * * *∼ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * (note) User can't use this instruction. Table5. Instruction set for AK9824 DAD01E-00 Comments read memory write memory write enable write disable power down enable power down disable set DAC outputs TEST (note) *: Don't Care Comments read memory write memory write enable write disable power down enable power down disable set DAC outputs TEST (note) *: Don't Care 1999/05 -6- ASAHI KASEI [AK9822/24] „ WRITE The WRITE instruction is followed by 16 bits of data to be written into the specified address. After the 32nd rising edge of SK to read the DI pin in, the AK9822/24 will be put into the automatic write time-out period. The DO pin indicates the Ready/Busy status of the EEPROM in the AK9822/24. After the 32nd rising edge of SK to read the Di pin in, the AK9822/24 will be put into the automatic write time-out period. When the automatic write time-out period starts, the DO pin outputs the Ready/Busy status. When the DO pin outputs the low level, the AK9822/24 is in the automatic write time-out and the next instruction can not be accepted. When the DO pin outputs the high level, the automatic write time-out period has ended and the AK9822/24 is ready for a next instruction. When the CS pin is changed to high level after confirmation of Ready/Busy signal on the DO pin, the DO pin becomes "Hi-Z". The Ready/Busy signal outputs until the CS pin is changed to high level, or the initial 1 bit ("1") of the next instruction is given to the part. WRITE (AK9824) DAD01E-00 1999/05 -7- ASAHI KASEI [AK9822/24] „ READ The READ instruction is the only instruction which outputs serial data on the DO pin. When the 17th falling edge of SK is received, the Do pin will come out of high impedance state and shift out the data from D15 first in descending order which is located at the address specified in the instruction. { Sequential READ When the clock is provided on the SK pin after the data in the specified address is read, the data in the next address is read. AK9822 • • When the clock is provided on the SK pin after the data in the address:7F (Hex) is read, the data in the address:00 (Hex) is read. AK9824 • • When the clock is provided on the SK pin after the data in the address:FF (Hex) is read, the data in the address:00 (Hex) is read. READ (AK9824) DAD01E-00 1999/05 -8- ASAHI KASEI [AK9822/24] „ WREN/WRDS There are two states such as the WRITE enable state and the WRITE disable state in the AK9822/24. In the WRITE disable state the WRITE instruction becomes invalid and is not executed. When Vcc is applied to the part, it powers up in the WRITE disable state. The WRITE instruction must be preceded by a WREN instruction. This state remains enabled until a WRDS instruction is executed or Vcc is removed from the part. Execution of a read instruction is not affected by both WREN and WRDS instruction. WREN/WRDS (AK9822/24) „ PDEN/PDDS There are two modes such as the power down mode and the normal mode in the AK9822/24. The mode of the part can be switched by the PDEN and PDDS instructions. The AK9822/24 becomes the power down mode by inputting the PDEN instructions. When the PDDS instruction is executed, the part becomes the normal mode. When returning to the normal mode from the power down mode, the D/A converters output the voltage value set before entering the power down mode. PDDS (AK9822/24) DAD01E-00 1999/05 -9- ASAHI KASEI [AK9822/24] „ CALL The outputs of the D/A converters is set by inputting a CALL instruction. Upper 8bit data (D15aD8) of the specified address corresponds to "A0". Lower 8bit data (D7aD0) of the specified address corresponds to "A1". The CALL instruction is not executed at the power down mode. CALL (AK9824) DAD01E-00 1999/05 - 10 - ASAHI KASEI [AK9822/24] Absolute Maximum Ratings Parameter Power supply Input voltage Ambient temperature Storage temperature Symbol VCC VIO Ta TST Conditions Relative to GND Relative to GND Spec. Units -0.6∼+7.0 -0.6∼VCC+0.6 -40∼+85 -65∼+150 V V °C °C Recommended Operating conditions Parameter Power supply Symbol Conditions min typ max Units VCC1 DAC operation 2.7 5.5 V VCC2 EEPROM operation 1.8 5.5 V 1 mA 1 mA 500 uA 500 uA 1.0 uF Analog output source current1 IAL1 Analog output sink current1 IAH1 Analog output source current2 IAL2 Analog output sink current2 IAH2 Analog output load capacitance AOC 3.6V≤VCC ≤5.5V 2.7V≤VCC