Electronic Components Datasheet Search |
|
ADDAC87 Datasheet(PDF) 11 Page - Analog Devices |
|
ADDAC87 Datasheet(HTML) 11 Page - Analog Devices |
11 / 16 page REV. B ADDAC80/ADDAC85/ADDAC87 –11– VOLTAGE OUTPUT MODELS Internal scaling resistors provided in the ADDAC80 may be connected to produce bipolar output voltage ranges of ±10 V, ±5 V or ±2.5 V or unipolar output voltage ranges of 0 V to +5 V or 0 V to +10 V (see Figure 9). REF INPUT TO REF CONTROL CIRCUIT FROM WEIGHTED RESISTOR NETWORK SUMMING JUNCTION 6.3k 5k 5k 18 20 16 + – OUTPUT COM BIPOLAR OFFSET 21 15 19 17 Figure 9. Output Amplifier Voltage Range Scaling Circuit Gain and offset drift are minimized in the ADDAC80 because of the thermal tracking of the scaling resistors with other device components. Connections for various output voltage ranges are shown in Table III. Settling time is specified for a full-scale range change: 4 s for a 10 k Ω feedback resistor; 3 s for a 5 kΩ feedback resistor when using the compensation capacitor shown in Figure 3a. The equivalent resistive scaling network and output circuit of the current model are shown in Figures 10 and 11. External RLS resistors are required to produce exactly 0 V to –2 V or ± 1 V output. TCR of these resistors should be ±100 ppm/°C or less to maintain the ADDAC80 output specifications. If exact output ranges are not required, the external resistors are not needed. 17 TO REF CONTROL CIRCUIT 6.3k 3k 2k 19 20 16 18 REF IN 5k 15 Figure 10. Internal Scaling Resistors 6.3k BIPOLAR OFFSET REFERENCE INPUT IOUT COMMON REFERENCE OUT 6.6k V TO REF CONTROL CIRCUIT 17 16 I 0 TO 2mA 6.3V 24 21 15 + – Figure 11. ADDAC80 Current Model Equivalent Output Circuit Internal resistors are provided to scale an external op amp or to configure a resistive load to offer two output voltage ranges of ±1 V or 0 V to –2 V. These resistors (RLI TCR = 20 ppm/ °C) are an integral part of the ADDAC80 and maintain gain and bipolar offset drift specifications. If the internal resistors are not used, exter- nal RL (or RF) resistors should have a TCR of ±25 ppm/°C or less to minimize drift. This will typically add ±50 ppm/°C + the TCR of RL (or RF) to the total drift. Table III. Output Voltage Range Connections, Voltage Model ADDAC80 Output Digital Connect Connect Connect Connect Range Input Codes Pin 15 to Pin 17 to Pin 19 to Pin 16 to ±10 V COB or CTC 19 20 15 24 ±5 V COB or CTC 18 20 NC 24 ±2.5 V COB or CTC 18 20 20 24 0 V to 10 V CSB 18 21 NC 24 0 V to 5 V CSB 18 21 20 24 0 V to 10 V CCD 19 NC 15 24 NC = No Connect DRIVING A RESISTIVE LOAD UNIPOLAR A load resistance, RL = RLI, + RLS, connected as shown in Figure 12 will generate a voltage range, VOUT, determined by: VmA kR kR OUT L L = × + – . . 2 66 66 Ω Ω (1) where RL max = 1.54 k Ω and V OUT max = –2.5 V To achieve specified drift, connect the internal scaling resistor (RLI) as shown in Table IV to an external metal film trim resistor (RLS) to provide full scale output voltage range of 0 V to –2 V. With RLS = 0 V, VOUT = –1.69 V. 0 TO 2mA CURRENT CONTROLLED BY DIGITAL INPUT 6.6k RLI 968 COMMON VOUT RLS + – 15 18 21 Figure 12. Equivalent Circuit ADDAC80-CBI-I Connected for Unipolar Voltage Output with Resistive Load |
Similar Part No. - ADDAC87 |
|
Similar Description - ADDAC87 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |