MC33341 Motorola, MC33341 Datasheet - Page 7

• Manufacturer Part Number: MC33341
• Description: POWER SUPPLY BATTERY CHARGER REGULATION CONTROL CIRCUIT
• Manufacturer: Motorola

The above figure shows the MC33341 configured for source high–side current sensing allowing a common ground path
between Load – and Source Return –. The Differential Amplifier inputs, Pins 1 and 6, are used to sense the load induced
voltage drop that appears across resistor R S . The internal voltage and current regulation thresholds are selected by the
respective external connections of Pins 2 and 6. Resistor R3 is required in applications where a high peak level of reverse
current is possible if the source inputs are shorted. The resistor value should be chosen to limit the input current of the internal
V CC clamp diode to less than 20 mA. Excessively large values for R3 will degrade the current sensing accuracy.
MOTOROLA ANALOG IC DEVICE DATA
Source
Source
Return
Isolator
Opto
V reg
+
+
V
1.2 R2
th(V)
R1
R2
R1
)
)
1
1
Figure 13. Source High–Side Current Sensing with
1.2 V
Internally Fixed Voltage and Current Thresholds
8
1
R
R
R
Differential Amp
Disable Logic
Differential Amp
Inverting Amp
R
R
R
V CC
V CC
0.4 V
7
2
MC33341
I reg
V CC
V CC
+
+
1.2 V
R S
V sen
I sen
V
0.2
R
V th
I th
th(I HS)
S
0.2 V
R
V CC
S
V
6
I
3
V CC
Transconductance
R3
V CC
Comp
0.2 V 0.4 V 1.2 V
Amp
Reference
V CC
V CC
5
4
R2
R3
+
I
pk
R1
R
0.02
S
– 0.6
Load
Load
Battery or
Resistive
Load
7