DatasheetQ Logo
Electronic component search and free download site.
Transistors,MosFET ,Diode,Integrated circuits

MC34060 View Datasheet(PDF) - ON Semiconductor

Part Name
Description
Manufacturer
MC34060 Datasheet PDF : 16 Pages
1 2 3 4 5 6 7 8 9 10 Next Last
MC34060A, MC33060A
6
5
RT
CT
Dead-Time 4
Control
Oscillator
0.12V
0.7V
0.7mA
+
1
-
Reference
10
Regulator
Dead-Time
- Comparator
+
-
+ PWM.
Comparator
+
2
-
Undervoltage
Lockout -
+
12
VTH
9
Q1 8
VCC
Ref Out
Collector
Emitter
1
2
Error Amp
1
3
Feedback/PWM
Comparator Input
13
14
Error Amp
2
7 GND
This device contains 46 active transistors.
Figure 1. Block Diagram
Description
The MC34060A is a fixedfrequency pulse width
modulation control circuit, incorporating the primary
building blocks required for the control of a switching power
supply (see Figure 1). An internallinear sawtooth oscillator
is frequencyprogrammable by two external components,
RT and CT. The approximate oscillator frequency is
determined by:
fosc ^
1.2
RT CT
For more information refer to Figure 3.
Output pulse width modulation is accomplished by
comparison of the positive sawtooth waveform across
capacitor CT to either of two control signals. The output is
enabled only during that portion of time when the sawtooth
voltage is greater than the control signals. Therefore, an
increase in controlsignal amplitude causes a corresponding
linear decrease of output pulse width. (Refer to the Timing
Diagram shown in Figure 2.)
Capacitor CT
Feedback/P.W.M.
Comparator
Dead-Time Control
Output Q1,
Emitter
Figure 2. Timing Diagram
http://onsemi.com
5
 

Share Link: 

datasheetq.com  [ Privacy Policy ]Request Datasheet ] [ Contact Us ]