2管脚 IMSB)DI REF 8-BIT D8-B0 MULTIPLYING INPUT DAC D REGISTER O D REGISTER CONVERTER 6 7 ILSB)Dlo o DSC05538-4 FIGURE 1. DAC0830 Functional Diagram
21 2.管脚
CS*: Chip Select (active low). The Cs in combination with ILE willl enable wr1.片选信号,输入线,低电平有效 WRI*: Write l(active low). The active low Wri is used to load the digital input data bits di into the input latch. The data in the input latch is latched when WrI is high. To update the input latch cS and wr1 must be low while Ile is high.写信号1,输入线, 低电平有效 WR2*: Write 2(active low). This signal, in combination with XFER, causes the 8-bit data which is available in the input latch to transfer to the dac register..写信号2:输入线,低电平有效
22 CS*: Chip Select (active low). The CS in combination with ILE will enable WR1. 片选信号,输入线,低电平有效. WR1*: Write 1 (active low). The active low WR1 is used to load the digital input data bits (DI) into the input latch. The data in the input latch is latched when WR1 is high. To update the input latch, CS and WR1 must be low while ILE is high. 写信号1,输入线, 低电平有效. WR2*: Write 2 (active low). This signal, in combination with XFER, causes the 8-bit data which is available in the input latch to transfer to the DAC register. 写信号2,输入线,低电平有效
ILE: Input Latch Enable (active high). The Ile in combination with cs enables wr1.输入允许锁存信号,输入线高电平有效 当E和CS同时有效时8位输入寄存器端为高电平“1”,此 时寄存器的输出端Q跟随输入端D的电平变化;反之,当端为低电 平“0”时原D端输入数据被锁存于Q端在此期间D端电平的变化 不影响Q端 XFER: Transfer control signal (active low). The XFER will enable wr2.传送控制信号辅入线,低电平有效 23
23 ILE: Input Latch Enable (active high). The ILE in combination with CS enables WR1. 输入允许锁存信号,输入线,高电平有效. 当ILE和CS*同时有效时,8位输入寄存器端为高电平“1”,此 时寄存器的输出端Q跟随输入端D的电平变化；反之,当端为低电 平“0”时,原D端输入数据被锁存于Q端,在此期间D端电平的变化 不影响Q端. XFER*: Transfer control signal (active low). The XFER will enable WR2. 传送控制信号,输入线, 低电平有效
D1O-DI7: Digital Inputs. DI7 is the most significant bit MSB). DIO is the least significant bit (LSB) 数据输入线其中D7为最高有效位MSB,D0为 最低有效位ISB, loutl: DAC Current Output 1. loutl is a maximum for a digital code of all 1s in the dac register, and is zero for all os in dac register. DAC电流输出端1,般作为运算放大器差动输入信号之一. lout2: DAC Current Output 2. IOUT2 is a constant minus(E)lout, or loutl+ lout= constant( full scale for a fixed reference voltage). DAC电流输出端2,一般作为运算放大器另一个差动输入信号 VREF、 Digital Input OUT 1 15 kQ 256 o02=EE×25pt 15 ks 256 24
24 DI0-DI7: Digital Inputs. DI7 is the most significant bit (MSB). DI0 is the least significant bit (LSB) 数据输入线,其中DI7为最高有效位MSB,DI0为 最低有效位LSB , Iout1: DAC Current Output 1. Iout1 is a maximum for a digital code of all 1’s in the DAC register, and is zero for all 0’s in DAC register. DAC电流输出端1,一般作为运算放大器差动输入信号之一. Iout2: DAC Current Output 2. IOUT2 is a constant minus(减) Iout1 , or Iout1+ Iout2 = constant (I fullscale for a fixed reference voltage). DAC电流输出端2,一般作为运算放大器另一个差动输入信号
Rib: Feedback Resistor. The feedback resistor is provided on the Ic chip for use as the shunt(i e )feed back resistor for the external op-amp which is used to provide an output voltage for the dac. This onchip resistor should always be used(not an external resistor)since it matches the resistors which are used in the on-chip r-2R ladder and tracks these resistors over temperature.固化在芯片內的反馈电阻连接端用于连接运 算放大器的输出端 4 REF Reference Voltage Input. This input connects an externalorecision oltage source to the internal r-2r ladder VREF can be selected over the range of+10to-10v.基准电压源端输入线,-10VDC~+10VDC Vcc: Digital Supply Voltage. This is the power supply pin for the part. Vce can be from+5t+ VDC. Operation is optimum for+5VDC.工作电 压源端,输入线, +5vdC N+15VDC
25 Rfb: Feedback Resistor. The feedback resistor is provided on the IC chip for use as the shunt(逃避) feedback resistor for the external op-amp which is used to provide an output voltage for the DAC. This onchip resistor should always be used (not an external resistor) since it matches the resistors which are used in the on-chip R-2R ladder and tracks these resistors over temperature. 固化在芯片内的反馈电阻连接端,用于连接运 算放大器的输出端. VREF：Reference Voltage Input. This input connects an external precision voltage source to the internal R-2R ladder. VREF can be selected over the range of +10 to −10V. 基准电压源端,输入线,−10VDC～+10VDC. Vcc: Digital Supply Voltage. This is the power supply pin for the part. Vcc can be from +5 to +15VDC. Operation is optimum for +15VDC. 工作电 压源端,输入线,+5VDC～+15VDC