MC33341

http://onsemi.com

11

R3

Load

R1

Battery or

Resistive

Load

Source

Return

Source

R2

Comp

The above figure shows the MC33341 configured for load high−side current sensing allowing common paths for both power and ground,

between the source and load. The Differential Amplifier inputs, Pins 1 and 6, are used to sense the load induced voltage drop that appears

6. Resistor R3 is required in applications where high peak levels of load current are possible from the battery or load bypass capacitor. The

R3 ill degrade the current sensing accuracy.

Vreg + Vth(V)

R2

R1

) 1

+ 1.2 R2

R1

) 1

Ireg +

V

th(IHS)

R

S

+ 0.2

R

S

R3

+

I

pk

R

S

– 0.6

0.02

V

I

Load

87

6

5

12

3

4

R

R

R

R

R

0.4 V

1.2 V

R

0.2 V

0.2 V 0.4 V 1.2 V

1.2 V

Inverting Amp

Transconductance

Amp

Differential Amp

Disable Logic

Differential Amp

Opto

Isolator

Reference

Figure 18. Load High−Side Current Sensing with

Internally Fixed Current and Voltage Thresholds