 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
DAC2904 Datasheet(PDF) 9 Page - Burr-Brown (TI) |
|
|
||||||||||||||||||||||||||||||
DAC2904 Datasheet(HTML) 9 Page - Burr-Brown (TI) |
|
|
9 / 19 page  DAC2904 9 SBAS198B FIGURE 1. Block Diagram of the DAC2904. APPLICATION INFORMATION THEORY OF OPERATION The architecture of the DAC2904 uses the current steering technique to enable fast switching and a high update rate. The core element within the monolithic DAC is an array of segmented current sources that are designed to deliver a full- scale output current of up to 20mA, as shown in Figure 1. An internal decoder addresses the differential current switches each time the DAC is updated and a corresponding output current is formed by steering all currents to either output summing node, IOUT or IOUT. The complementary outputs deliver a differential output signal, which improves the dynamic performance through reduction of even-order har- monics, common-mode signals (noise), and double the peak- to-peak output signal swing by a factor of two, compared to single-ended operation. The segmented architecture results in a significant reduction of the glitch energy, improves the dynamic performance (SFDR), and DNL. The current outputs maintain a very high output impedance of greater than 200ký. The full-scale output current is determined by the ratio of the internal reference voltage (1.25V) and an external resistor, RSET. The resulting IREF is internally multiplied by a factor of 32 to produce an effective DAC output current that can range from 2mA to 20mA, depending on the value of RSET. The DAC2904 is split into a digital and an analog portion, each of which is powered through its own supply pin. The digital section includes edge-triggered input latches and the decoder logic, while the analog section comprises the cur- rent source array with its associated switches, and the reference circuitry. DAC TRANSFER FUNCTION Each of the DACs in the DAC2904 has a set of complemen- tary current output, IOUT1 and IOUT2. The full-scale output current, IOUTFS, is the summation of the two complementary output currents: IOUTFS = IOUT + IOUT (1) The individual output currents depend on the DAC code and can be expressed as: IOUT = IOUTFS • (Code/16384) (2) IOUT = IOUTFS • (16383 - Code/16384) (3) where ‘Code’ is the decimal representation of the DAC data input word. Additionally, IOUTFS is a function of the refer- ence current IREF, which is determined by the reference voltage and the external setting resistor, RSET. IOUTFS = 32 • IREF = 32 • VREF/RSET (4) In most cases the complementary outputs will drive resistive loads or a terminated transformer. A signal voltage will develop at each output according to: VOUT = IOUT • RLOAD (5) VOUT = IOUT • RLOAD (6) DAC Latch 1 WRT1 CLK1 CLK2 WRT2 Data Input Port 2 D[13:0]_2 Data Input Port 1 D[13:0]_1 l OUT1 l OUT1 Input Latch 1 Reference Control Amplifier FSA2 REF IN FSA1 GSET PD DAC1 Segmented Switches Current Sources DAC2904 l OUT2 l OUT2 +V A +V D +V D DAC Latch 2 Input Latch 2 DAC2 Segmented Switches Current Sources AGND DGND DGND |
Similar Part No. - DAC2904 |
|
Similar Description - DAC2904 |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | 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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
