MC33342 ON Semiconductor, MC33342 Datasheet - Page 10

• Manufacturer Part Number: MC33342
• Description: (MC33340 / MC33342) Battery Fast Charge Controllers
• Manufacturer: ON Semiconductor

Input
Line
AC
This application combines the MC33340/342 with an adjustable three terminal regulator to form an isolated secondary side battery charger. Regulator IC2
operates as a constant current source with R7 setting the fast charge level. The trickle charge level is set by R5. The R2/R1 divider should be adjusted so
that the V
sinks for IC2 and are all manufactured by AAVID Engineering Inc.
sen
Each test mode bypass switch is shown
in the proper position for normal charger operation.
Oscillator
760 kHz
input is less than 2.0 V when the batteries are fully charged. The printed circuit board shown below will accept the several TO−220 style heat-
Charge
Status
Input
1.8 k
DC
R6
D1
R2 + R1
I chg(fast) +
I chg(trickle) +
÷2
3
Frequency
Voltage to
Converter
I
Adj
LM317
SCK to
1.0 k
95 kHz
R5
IC2
V Batt
V sen
Switch 2
D4
V ref ) (I Adj R8)
1N4002
÷2
2
V in – V f(D3) – V Batt
220
R8
11
D3
6
– 1
R7
2.4
Figure 12. Line Isolated Linear Regulator Charger
D2
R7
R5
Figure 11. Timer Functional Block Diagram
÷2
R2
R1
2
Trickle
0.01
C1
Gate
Fast/
V
V
sen
sen
MC33340, MC33342
2
3
1
÷2
http://onsemi.com
3
Switch 3B
2.0 V
1.0 V
2
11
Internal Bias
÷2
Holdoff Time Signal
10
1
Frequency
Voltage to
Converter
Q
Battery
Detect
Test
Switch 1
IC1 MC33340 or MC33342
2
÷2
Ck
MC33340
High
Low
V
Gate
F/T
2
19
Gnd
−DV Detect
sen
5
5
D
Switch 3A
Counter
Normal
Timer
F/V R
Under
4
Q
Over
MC33342
÷2
t/T
t1
t2
t3
Undervoltage
t1/T
t2/T
t3/T
8
Lockout
Time/Temp
ref
sen
ref
Q
Select
High
Low
R
S
Detect
22 ms Convert
Temp
11 ms Preset
÷2
Over
Temp
Latch
2
V
CC
0.6 V
8
Time and Test Decoder
2.9 V
V
÷2
V
Fast/Trickle Output
CC
CC
30 mA
30 mA
30 mA
÷2
C2
0.1
t1/T
t2/T
t3/T
7
6
5
÷2
ref
sen
ref
Battery
Low
High
Pack
SW1
SW3
÷2
SW2
R
10 k
NTC
R3
R4