Rainbow-electronics DS1852 User Manual

1 of 25 040302FEATURES§ Implements proposals of SFF-8472 at device address A2h[Note: requires use of external EEPROM at addressA0h for full complianc

DS185210 of 252-WIRE SERIAL PORT OPERATIONThe 2-wire serial port interface supports a bidirectional data transmission protocol with deviceaddressing.

DS185211 of 25A device that acknowledges must pull down the SDA line during the acknowledge clock pulse in such away that the SDA line is a stable LOW

DS185212 of 252-WIRE DATA TRANSFER PROTOCOL Figure 22-WIRE AC CHARACTERISTICS Figure 3

DS185213 of 25MEMORY MAPMemory access to the DS1852 is through the 2-wire interface. See the 2-WIRE OPERATION section.The memory within the DS1852 is

DS185214 of 25Table 00h-FFh (Lower)Address Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7bits<7-0> bits<7-0> bits<7-0> bits

DS185215 of 25Table 00h (Lower)Memory Location(Table 00h, Lower)Name of Location Function00h – 5Fh IEEE Data This memory block is used to store requir

DS185216 of 25Table 00h (Upper)AddressByte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7bits<7-0> bits<7-0> bits<7-0> bits<7

DS185217 of 25Table 03h (Upper)Address Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7bits<7-0> bits<7-0> bits<7-0> bits<

DS185218 of 25Table 03hMemory Location(Table 3)Name of Location Function of Location80h – 81h88h – 89h90h – 91h98h – 99hA0h – A1hTemperature High Alar

DS185219 of 25ABSOLUTE MAXIMUM RATINGS*Voltage on Any Pin Relative to Ground -0.3V to +6.0VOperating Temperature Range -40°C to +125°C Programming Tem

DS18522 of 25PIN DESCRIPTIONSName Ball Locations DescriptionVCC D2, D4, E3 Power-Supply Terminal. The DS1852 will support supply voltagesranging from

DS185220 of 25A/D CONVERTERS (-40°C to +100°C; VCC = 2.7V to 5.5V)PARAMETER SYMBOL CONDITIONS MIN MAX UNITS NOTESTherm

DS185221 of 25AC ELECTRICAL CHARACTERISTICS (-40°C to +100°C, VCC = 2.7V to 5.5V)PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS NOTESSCL ClockFrequ

DS185222 of 25NOTES1) All voltages are referenced to ground.2) This is the time for one comparison. The complete cycle is this value multiplied by 3

DS185223 of 25SCALING THE ADCprocedure writeTrimValue(trim :integer); (* write trim to part *)procedure forceReference(Vin: real); (* applies referenc

DS185224 of 25beginbestTrim := trim;if (Bit > 11) thenBegintrim := trim - lshft(1,trimBit);end;end;end;(* The upper 4 bits of bestTrim contains the

DS185225 of 25MECHANICAL DRAWING

DS18523 of 25DS1852 BLOCK DIAGRAM Figure 1EEPROM2-WIREInterfaceControlControlControlControlControlControlControlSignalsALARMandWARNADCFASTTRIP5:1MUX3:

DS18524 of 25DEVICE OPERATIONSecurityTo prevent accidental overwrites of key device data, a data lockout feature is incorporated. A 32-bitpassword pro

DS18525 of 25ANALOG-TO-DIGITAL CONVERTERThe ADC reads a total of five inputs: VCC (internal), temperature (internal), and external inputs Bin, Pin,and

DS18526 of 25bits. This step has now adjusted the LSB of the lower 12 bits so that the best possible trim isacquired with the lower 12 bits.If too hig

DS18527 of 25DIGITAL INPUTSThe four digital inputs (Din, RSin, Fin, and Lin) can be read through the 2-wire bus. The logic levels atthese inputs are m

DS18528 of 25Write OperationsAfter receiving a matching address byte with the R/W bit set low, the device goes into the write mode ofoperation. The ma

DS18529 of 25Once the device address is clocked in and acknowledged by the DS1852 with the R/W bit set to high,the current address data word is clocke