DS1851 Dallas Semiconducotr, DS1851 Datasheet
DS1851
Related parts for DS1851
DS1851 Summary of contents
Page 1
... Both of the DACs can be programmed with any temperature coefficient, which means that any system temperature effects can be corrected without any additional external devices. The DS1851 provides an ideal method for setting and temperature- compensating bias voltages and currents in control applications using a minimal amount of external circuitry ...
Page 2
... DS1851 BLOCK DIAGRAM Figure 1 2-Wire SDA Interface SCL V CC GND Digital Temperature Sensor 4 DataSheet U .com 40x8 bit 40x8 bit EEPROM EEPROM Look-Up Table 2 Look-Up Table 1 (DAC-G) (DAC-V) Table Select Byte Configuration Byte Temperature MSB Byte Temperature LSB Byte Address Pointer ...
Page 3
... Serial Clock Input. The serial clock input is used to clock data into the DS1851 on rising edges and clock data out on falling edges. DAC-G Output. This calculated output is between V DAC-V Output. This calculated output is between V Reference Input from GND ...
Page 4
... Temperature LSB 63h Address Pointer 64h User Memory 65h-6Fh DAC-V Setting 70h DAC-G Setting 71h User Memory 72h-7Fh 80h 40x8 bit 40x8 bit EEPROM EEPROM Look-Up Table 1 Look-Up Table 2 A7h (DAC-V) (DAC-G) Read-Only Read-Only Memory (TBD) Memory (TBD DS1851 ...
Page 5
... This byte contains the MSB of the 12-bit 2’s complement temperature output from the temperature sensor DS1851 ...
Page 6
... For example, memory address 81h is the address that will set the DAC in a -36°C environment. OutV = – DACreg1/255 OutG = – GND) * DACreg2/255 DS1851 - and V as the reference and GND as the rg ...
Page 7
... The values of the DACs are determined by the temperature-addressed look-up table that assigns a unique value to both for every 4°C increment with a 1°C hysteresis at a temperature transition over the operating temperature range. (See Figure 2.) MEMORY LOCATION OVER TEMPERATURE Figure DataSheet U .com Temperature (° DS1851 Increasing temp Decreasing temp ...
Page 8
... The DS1851 must receive an 8-bit device address word following a START condition to enable a specific device for a read or write operation. The address word is clocked into the DS1851 MSB to LSB. The address word consists of Ah (1010) followed by 000 then the R/W bit. If the R/W bit is high, a read operation is initiated ...
Page 9
... All inputs are disabled during this byte write cycle. The DS1851 is capable of an 8-byte page write. A page write is initiated the same way as a byte write, but the master does not send a STOP condition after the first byte. Instead, after the slave acknowledges receipt of the data byte, the master can send up to seven more bytes using the same nine-clock sequence ...
Page 10
... Sequential reads are initiated by either a current address read or a random address read. After the master receives the first data byte, the master responds with an acknowledge. As long as the DS1851 receives this acknowledge after a byte is read, the master may clock out additional data words from the DS1851. After reaching address FFh, it resets to address 00h. ...
Page 11
... Within the bus specifications, a regular mode (100kHz clock rate) and a fast mode (400kHz clock rate) are defined. The DS1851 works in both modes. Acknowledge: Each receiving device, when addressed, generates an acknowledge after the reception of each byte. The master device must generate an extra clock pulse that is associated with this acknowledge bit ...
Page 12
... Slave transmitter mode: The first byte is received and handled as in the slave receiver mode. However, in this mode the direction bit will indicate that the transfer direction is reversed. Serial data is transmitted on SDA by the DS1851 while the serial clock is input on SCL. START and STOP conditions are recognized as the beginning and end of a serial transfer. ...
Page 13
... DATA TRANSFER PROTOCOL Figure 3 2-WIRE TIMING DIAGRAM Figure 4 4 DataSheet U .com DS1851 ...
Page 14
... V SYMBOL CONDITION MIN 0. GND - IL 0.3 -10 0.4<V <0.9V I 3mA sink OL1 current V 6mA sink OL2 current (-40°C to +95°C) TYP MAX UNITS +5 +3.0V to +5.5V) CC TYP MAX UNITS NOTES 0 0 0.6 V DS1851 NOTES 1 8 ...
Page 15
... SU:STO Standard Mode 4.0 t Fast Mode 3.0V to 5.5V) CC TYP MAX UNITS 0 400 kHz 0 100 0 300 ns B 1000 300 ns B 300 400 DS1851 NOTES ...
Page 16
... Source/sink -10 150µ out V GND ref GND + V ref 0.5 SYMBOL CONDITION T -40°C to +95°C ERR t 12-bit conversion CONVT DS1851 - 0. +3.0V to +5.5V TYP MAX UNITS NOTES bits ±2 LSB ±1 LSB + +0.8 % 10 1000 ...
Page 17
... SCL line is released. RMAX SU:DAT has only to be met if the device does not stretch the LOW period ( and V = GND. The outputs OutV and OutG are left open 1.25 + GND DS1851 > 250ns must SU:DAT ) of the LOW ) and (0.1)( ...