Electronic Components Datasheet Search |
|
LTC1100 Datasheet(PDF) 7 Page - Linear Technology |
|
LTC1100 Datasheet(HTML) 7 Page - Linear Technology |
7 / 8 page LTC1100 7 1100fc Common Mode Rejection Due to very precise matching of the internal resistors, no trims are required to obtain a DC CMRR of better than 100dB; however, things change as frequency rises. The inverting amplifier is in a gain of 1.01 (1.1 for gain of 10), while the noninverting amplifier is in a gain of 99 (9 for gain of 10). As frequency rises, the higher gain amplifier hits its gain-bandwidth limit long before the low gain amplifier, degrading CMRR. The solution is straightforward — slow down the inverting amplifier to match the noninverting amp. Figure 1 shows the recommended circuit. The prob- lem is less pronounced in the LTC1100CS in gain-of-10 mode; no CMRR trims are necessary. Figure 2. Overcompensation to Reduce System Bandwidth 100k 10pF 3 LTC1100 • TA02 2 8 6 + − + − LTC1100 Figure 1. Improving AC CMRR Overcompensation Many instrumentation amplifier applications process DC or low frequency signals only; consequently, the 18kHz (180kHz for G = 10) bandwidth of the LTC1100 can be reduced to minimize system errors or reduce transmitted clock noise by using the COMP pin. A feedback cap from COMP to VOUT will react with the 247k internal resistor (22.5k for G = 10) to limit the bandwidth, as in Figure 2. 3 LTC1100 • TA03 8 6 + – C 7 f = 3dB 1 2 R × C π INT R = 247k FOR G = 100 22.5k FOR G = 10 INT B LTC1100 B Aliasing The LTC1100 is a chopper-stabilized instrumentation amplifier; like all sampled systems it exhibits aliasing behavior for input frequencies at or near the internal sampling frequency. The LTC1100 incorporates special- ized anti-aliasing circuitry which typically attenuates aliasing products by ≥ 60dB; however, extremely sensi- tive systems may still have to take precautions to avoid aliasing errors. For more information, see the LTC1051/ LTC1053 data sheet. Single Supply Operation The LTC1100 will operate on a single 5V supply, and the common mode range of the internal op amps includes ground; single supply operation is limited only by the output swing of the op amps. The internal inverting amplifier has a negative saturation limit of 5mV typically, setting the minimum common mode limit at 5mV/1.01 (or 1.1 for gain of 10). The inputs can be biased above ground, as shown in Figure 3. Low cost biasing components can be used since any errors appear as a common mode term and are rejected. The minimum differential input voltage is limited by the swing of the output op amp. Lightly loaded, it will swing down to 5mV, allowing differential input voltages as low as 50µV (450µV for gain of 10). Single supply operation limits the LTC1100 to positive differential inputs only; negative inputs will give a saturated zero output. 3 5V LTC1100 • TA04 8 6 − + OUTPUT 0V TO 5V SENSOR RBIAS 5 4, 1 5V 1N4148 LTC1100 Figure 3 Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. APPLICATIO S I FOR ATIO |
Similar Part No. - LTC1100 |
|
Similar Description - LTC1100 |
|
|
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 |