MC33340 MC33342

11

MOTOROLA ANALOG IC DEVICE DATA

Figure 16. Switch Mode Fast Charger

The MC33340/342 can be used to control the MC34166 or MC34167 power switching regulators to produce an economical and efficient fast charger. These devices

are capable of operating continuously in current limit with an input voltage range of 7.5 to 40 V. The typical charging current for the MC34166 and MC34167 is 4.3

A and 6.5 A respectively. Resistors R2 and R1 are used to set the battery pack fast charge float voltage. If precise float voltage control is not required, components

R1, R2, R3 and C1 can be deleted, and Pin 1 must be grounded. The trickle current level is set by resistor R4. It is recommended that a redundant charge termination

method be employed for end user protection. This is especially true for fast charger systems. For additional converter design information, refer to the MC34166 and

MC34167 data sheets.

Q

S

R

Vsen

Gate

Fast/

Trickle

3

Vsen

Gate

F/T

MC33340/342

Gnd

4

2

AC

Line

Input

MC34166 or MC34167

Osc

PWM

Thermal

ILimit

VCC

4

2

1

Switch

Output

+

R4

R2

Voltage

Feedback

Input

Battery

Pack

EA

Ref

UVLO

Gnd

3

Compensation

5

C1

R3

R1