SG3526 Motorola Inc, SG3526 Datasheet - Page 6

• Manufacturer Part Number: SG3526
• Description: PULSE WIDTH MODULATION CONTROL CIRCUIT
• Manufacturer: Motorola Inc

– Error
Q1
6
14 A
2.5
2.0
1.5
1.0
0.5
0
125
2.0
A
1.0k
Figure 7. V C Saturation Voltage as a
Q3
Q7
50 A
V CC
5.0
Q6
Function of Sink Current
Figure 9. Error Amplifier
500
Q5
Q8
I C , SINK CURRENT (mA)
10
50 A
PWM
Sync
100
A
Q9
Q4
1.0k
20
Metering
D
14 A
F/F
S
+ Error
Q2
50
Q
Q
Q11
1
V ref
Figure 11. Pulse Processing Logic
Q10
Memory
S
R
F/F
Q12
100
500
100 A
Q
100 A
3 Compensation
200
SG3526
Clock
PWM
The metering Flip–Flop is an asynchronous data latch
which suppresses high frequency oscillations by allowing
only one PWM pulse per oscillator cycle.
The memory Flip–Flop prevents double pulsing in a
push–pull configuration by remembering which output
produced the last pulse.
200
100
5.0
2.0
50
20
10
Reference
Bandgap
1.2V
R D = 0
Figure 10. Undervoltage Lockout
V ref
Figure 8. Oscillator Period
MOTOROLA ANALOG IC DEVICE DATA
R1
R2
OSCILLATOR PERIOD (ms)
+
–
To Reset
To Driver A
To Driver B