mc33157dw ON Semiconductor, mc33157dw Datasheet - Page 8

• Manufacturer Part Number: mc33157dw
• Description: Half Bridge Controller And Driver For Industrial Linear Tubes
• Manufacturer: ON Semiconductor

DETECTION
(PREHEAT)
Frequency
Output Frequency
Frequency
3.8 V typ
9.2 V typ
SWEEP
STRIKE
RESET
U
V
Rise time
U
Output
V
DETECTION
VON
CPH
V
status
VLO
DD
ref
RESET
V
STRIKE
+V
CSWP
1
0
status
ref
OFF STATE
w
f 1 = f PH , preheating frequency adjusted by R PH and R ENDSWEEP
f 2 = f ENDSWEEP , end of sweep frequency, adjusted by R ENDSWEEP ( pin 2). In any case f 1
f 3 = f OP , operating frequency controlled by the I CO current (pin 7) and capacitor C OP
t PH = (C PH * 2/3 * Vref) / ( * I tPH )
“OFF” state: High side switch OFF, Low side switch ON
lms
1
0
Previous On state
When RESET pin is released to a logic one, the system jumps to the preheat frequency as defined by RPH,
then executes a frequency sweep down to f ENDSWEEP , as defined by R ENDSWEEP , and waits until a strike
detection signal is applied to pin 9. There is no preheating timing performed after a reset coming from pin 10.
RESET logic level is CMOS compatible.
Note: Strike detection lever can be either digital – CMOS or analog as depicted here above, as long as the
signal fulfills the SD HIGH and SD LOW values and timing.
OFF STATE: both output MOSFET are biased in the off condition.
F3
Figure 9. TIMING DIAGRAM (Normal startup sequence and U VLO reset)
tph
F1
Figure 10. TIMING DIAGRAM (External reset)
OFF STATE
w
10 s
m
F2
t
STRIKE
http://onsemi.com
w
F3
1 s
m
MC33157
SD
8
HIGH
FSweep
OFF STATE
7.0 V typ
U
VLO
RESET
SD
LOW
w
f 2
F1
F3
V
No further logic action activated
CSWP
repeats indefinitely
F2
time
F3
time