TL331 datasheet(9/18 Pages) TI1

9 / 18 page

TL331

www.ti.com

SLVS238G – AUGUST 1999 – REVISED JANUARY 2015

9.2.2.1 Input Voltage Range

When choosing the input voltage range, the input common mode voltage range (VICR) must be taken in to

account. If temperature operation is above or below 25°C the VICR can range from 0 V to VCC – 1.5 V. This limits

the input voltage range to as high as VCC – 1.5 V and as low as 0 V. Operation outside of this range can yield

incorrect comparisons.

Below is a list of input voltage situation and their outcomes:

1. When both IN- and IN+ are both within the common mode range:

(a) If IN- is higher than IN+ and the offset voltage, the output is low and the output transistor is sinking

current

(b) If IN- is lower than IN+ and the offset voltage, the output is high impedance and the output transistor is

not conducting

2. When IN- is higher than common mode and IN+ is within common mode, the output is low and the output

transistor is sinking current

3. When IN+ is higher than common mode and IN- is within common mode, the output is high impedance and

the output transistor is not conducting

4. When IN- and IN+ are both higher than common mode, the output is low and the output transistor is sinking

current

9.2.2.2 Minimum Overdrive Voltage

Overdrive Voltage is the differential voltage produced between the positive and negative inputs of the comparator

over the offset voltage (VIO). In order to make an accurate comparison the Overdrive Voltage (VOD) should be

higher than the input offset voltage (VIO). Overdrive voltage can also determine the response time of the

comparator, with the response time decreasing with increasing overdrive. Figure 5 and Figure 6 show positive

and negative response times with respect to overdrive voltage.

9.2.2.3 Output and Drive Current

Output current is determined by the load/pull-up resistance and logic/pull-up voltage. The output current will

produce a output low voltage (VOL) from the comparator. In which VOL is proportional to the output current. Use

Figure 3 to determine VOL based on the output current.

The output current can also effect the transient response. More will be explained in the next section.

9.2.2.4 Response Time

The transient response can be determined by the load capacitance (CL), load/pull-up resistance (RPULLUP) and

equivalent collector-emitter resistance (RCE).

•

The positive response time (

τp) is approximately τP ~ RPULLUP × CL

•

The negative response time (

τN) is approximately τN ~ RCE × CL

–

RCE can be determine by taking the slope of Figure 3 in it's linear region at the desired temperature, or by

dividing the VOL by Iout

Submit Documentation Feedback

Product Folder Links: TL331

TL331 データシート(PDF) 9 Page - Texas Instruments

TL331 データシート(HTML) 9 Page - Texas Instruments

Html Pages

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

データシートダウンロード