Data Sheet

21

Rev 1.1, 2010-09-30

H-Bridge and Dual Half Bridge Driver IC

TLE7182EM

5.3

Shunt Signal Conditioning

The TLE7182EM incorporates a fast and precise operational amplifier for conditioning and amplification of the

current sense shunt signal. The gain of the OpAmp is adjustable by external resistors within a range higher than 5.

The usage of higher gains in the application might be limited by required settling time and band width.

It is recommended to apply a small offset to the OpAmp, to avoid operation in the lower rail at low currents.

The output of the OpAmp ISO is not short-circuit proof.

Figure 5

Shunt Signal Conditioning Block Diagram and Over Current Limitation

Over current warning see Chapter 5.2.7.

5.3.1

Electrical Characteristics

Electrical Characteristics - Current sense signal conditioning

V

(unless otherwise specified)

Pos.

Parameter

Symbol

Limit Values

Unit

Conditions

Min.

Typ.

Max.

5.3.1

Series resistors

R

S

100

500

1000

Ω

–

5.3.2

Feedback resistor

Limited by the output voltage

dynamic range

R

fb

2000

7500

–

Ω

–

5.3.3

Resistor ratio (gain ratio)

R

fb/RS

5

–––

–

5.3.4

Steady state differential input

voltage range across VIN

V

IN(ss)

-400

–

400

mV

–

5.3.5

Input differential voltage (ISP - ISN)

V

IDR

-800

–

800

mV

–

5.3.6

Input voltage (Both Inputs - GND)

(ISP - GND) or (ISN -GND)

V

LL

-800

–

2000

mV

–

5.3.7

Input offset voltage of the I-DC link

OpAmp, including temperature drift

V

IO

–

–

+/-2

mV

R

V

5.3.8

Input bias current (ISN,ISP to GND)

I

IB

-300

–

–

µA

V

5.3.9

Low level output voltage of ISO

V

OL

-0.1

–

0.2

V

I

external

R

S1

R

S2

TLE718xEM

-

+

-

+

V

OCTH

ERR

R

REF1

R

FB

R

shunt

V

DD

ISN

ISP

ISO

R

REF2

R