LT1805CS datasheet(14/20 Pages) LINER

14 / 20 page

LT1803/LT1804/LT1805

180345f

If both amplifiers are loaded simultaneously, then the total

power dissipation is 0.19W.

The maximum ambient temperature that the part is al-

lowed to operate is:

TA = TJ – (PDMAX • 190°C/W)

= 150

°C – (0.190W • 190°C/W) = 113.9°C

Similar calculations can be carried out for specific pack-

ages and conditions.

Also worth noting, the DD package includes a low

θJA

underside metal which is internally connected to VS–. If the

underside metal is properly soldered to a PCB, the

θJA of

the part will be close to 50

°C/W. This θJA is significantly

less than leaving the underside metal unattached and can

be useful for certain applications.

Input Offset Voltage

The input offset voltage will change greatly based upon

which input stage is active. The PNP input stage is active

from the negative supply voltage to about 1.3V below the

positive supply rail, then the NPN input stage is activated

for the remaining input range up to the positive supply rail

during which the PNP stage remains inactive. The offset

voltage is typically less than 1000

µV in the range the PNP

input stage is active.

Input Bias Current

The LT1803/LT1804/LT1805 employ a patent-pending

technique to reduce the input bias current to less than 1

µA

for the input common mode voltage range of 0.2V above

the negative supply rail to 1.75V below the positive rail.

The low input offset voltage and low input bias current

provide precision performance in high source impedance

applications.

Output

The LT1803/LT1804/LT1805 can deliver a large output

current, so the short-circuit current limit is set around

50mA to prevent damage to the device. Attention must be

paid to keep the junction temperature of the IC below the

absolute maximum rating of 150

°C (refer to the Power

Dissipation section) when the output is continuously short

circuited. The output of the amplifier has reverse-biased

diodes connected to each supply. If the output is forced

beyond either supply, unlimited current will flow through

these diodes. If the current is transient and limited to less

than 100mA and the total supply voltage is less than

APPLICATIO S I FOR ATIO

Figure 1. LT1803/LT1804/LT1805 Simplified Schematic Diagram

Q18

Q17

Q16

Q10

Q13

Q15

OUT

Q11

Q12

VBIAS

ESDD2

ESDD1

+IN

–IN

V–

ESDD3

ESDD4

V+

V–

Q14

180345 F01

V–

BUFFER

AND

OUTPUT BIAS

V+

V–

Q19

LT1805CS датащи(PDF) 14 Page - Linear Technology

LT1805CS датащи(HTML) 14 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

датащи скачать

ссылки URL