The AD7376 provides a single channel, 128-position digitallycontrolled variable resistor (VR) device. This device performs the same electronic adjustment function as a potentiometer or variable resistor. These products were optimized for instrument and test equipment applications where a combination of high voltage with a choice between bandwidth or power dissipation are available as a result of the wide selection of end-to-end terminal resistance values. The AD7376 contains a fixed resistor with a wipercontact that taps the fixed resistor value at a point determined by a digital code loaded into the SPI-compatible serial-input register. The resistance between the wiper and either endpoint of the fixed resistor varies linearly with respect to the digital code transferred into the VR latch. The variable resistor offers a completely programmable value of resistance between the A terminal and the wiper or the B terminal and the wiper. The fixed A to B terminal resistance of 10 kW, 50 kW, 100 kW or 1 MW has a nominal temperature coefficient of 300 ppm/°C.
The VR has its own VR latch which holds its programmed resistance value. The VR latch is updated from an internal serial-toparallel shift register which is loaded from a standard 3-wire
serial-input digital interface. Seven data bits make up the data word clocked into the serial data input register (SDI). Only the last seven bits of the data word loaded are transferred into the 7-bitVRlatchwhen the CS strobe is returned to logic high. A serial data output pin (SDO) at the opposite end of the serial register allows simple daisy-chaining in multipleVRapplications
without additional external decoding logic. The reset (RS ) pin f
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Mechanical Potentiometer ReplacementInstrumentation: Gain, Offset AdjustmentProgrammable Voltage-to-Current ConversionProgrammable Filters, Delays, Time ConstantsLine Impedance MatchingPower Supply Adjustment
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128 PositionPotentiometer Replacement10 kV, 50 kV, 100 kV, 1 MVPower Shutdown: Less than 1 mA3-Wire SPI Compatible Serial Data Input+5 V to +30 V Single Supply Operation65 V to 615 V Dual Supply OperationMidscale Preset
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VDD to GND . . . . . . . . . . . . . . . . . . . . . . . . ... .. . 0.3 V, +30 V
VSS to GND . . . . . . . . . . . . . . . . . . . . . . . .. .. .. +0.3 V, 16.5 V
VDD to VSS . . . . . . . . . . . . . . . . . . . . . . . .. . . .. . 0.3 V, +44 V
VA, VB, VW to GND . . . . . . . . . . . . . . . . . . . ... . . . . . . VSS, VDD
AX BX, AX WX, BX WX . . . . . . . . . . . .. . .. . . . . . ±20 mA
Digital Input Voltages to GND . . . . . . . . . ....... 0 V, VDD + 0.3 V
Digital Output Voltage to GND . . . . . . . . . . ........ . . . 0 V, +30 V
Operating Temperature Range . . . . . . . . . .. 40°C to +85°C
Maximum Junction Temperature (TJ MAX) . . . . .,,,,,,,, . .+150°C
Storage Temperature . . . . . . . . . . . . . . . . . 65°C to +150°C
Lead Temperature (Soldering, 10 sec) . . . . . . .... . . . . .+300°C
Package Power Dissipation . . . . . . . . . ..... . . (TJ MAX TA)/qJA
Thermal Resistance qJA
P-DIP (N-14) . . . . . . . . . . . . . . . . . . . . . . . . ........... . . . 92°C/W
SOIC (SOL-16) . . . . . . . . . . . . . . . . . . . . . . . . .......... . 120°C/W
TSSOP-14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .......... . 240°C/W
Post a Buying Lead
Required Field 
