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SG3525A SG3527A
2
MOTOROLA ANALOG IC DEVICE DATA
MAXIMUM RATINGS
(Note 1)
Rating
Symbol
Value
Unit
Supply Voltage
VCC
VC
+40
Vdc
Collector Supply Voltage
+40
Vdc
Logic Inputs
–0.3 to +5.5
V
Analog Inputs
–0.3 to VCC
±
500
V
Output Current, Source or Sink
IO
Iref
mA
Reference Output Current
50
mA
Oscillator Charging Current
5.0
mA
Power Dissipation (Plastic & Ceramic Package)
TA = +25
°
C (Note 2)
TC = +25
°
C (Note 3)
PD
1000
2000
mW
Thermal Resistance Junction–to–Air
R
θ
JA
R
θ
JC
TJ
Tstg
TSolder
100
°
C/W
Thermal Resistance Junction–to–Case
60
°
C/W
Operating Junction Temperature
+150
°
C
Storage Temperature Range
–55 to +125
°
C
Lead Temperature (Soldering, 10 seconds)
+300
°
C
NOTES:
1.Values beyond which damage may occur.
2.Derate at 10 mW/
°
C for ambient temperatures above +50
°
C.
3.Derate at 16 mW/
°
C for case temperatures above +25
°
C.
RECOMMENDED OPERATING CONDITIONS
Characteristics
Symbol
Min
Max
Unit
Supply Voltage
VCC
VC
IO
8.0
35
Vdc
Collector Supply Voltage
4.5
35
Vdc
Output Sink/Source Current
(Steady State)
(Peak)
0
0
±
100
±
400
mA
Reference Load Current
Iref
fosc
RT
CT
RD
TA
0
20
mA
Oscillator Frequency Range
0.1
400
kHz
Oscillator Timing Resistor
2.0
150
k
Oscillator Timing Capacitor
0.001
0.2
μ
F
Deadtime Resistor Range
0
500
Operating Ambient Temperature Range
0
+70
°
C
APPLICATION INFORMATION
Shutdown Options
(See Block diagram, front page)
Since both the compensation and soft–start terminals
(Pins 9 and 8) have current source pull–ups, either can
readily accept a pull–down signal which only has to sink a
maximum of 100
μ
A to turn off the outputs. This is subject to
the added requirement of discharging whatever external
capacitance may be attached to these pins.
An alternate approach is the use of the shutdown circuitry
of Pin 10 which has been improved to enhance the available
shutdown options. Activating this circuit by applying a
positive signal on Pin 10 performs two functions: the PWM
latch is immediately set providing the fastest turn–off signal to
the outputs; and a 150
μ
A current sink begins to discharge
the external soft–start capacitor. If the shutdown command is
short, the PWM signal is terminated without significant
discharge of the soft–start capacitor, thus, allowing, for
example, a convenient implementation of pulse–by–pulse
current limiting. Holding Pin 10 high for a longer duration,
however, will ultimately discharge this external capacitor,
recycling slow turn–on upon release.
Pin 10 should not be left floating as noise pickup could
conceivably interrupt normal operation.