UCC28951
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ZHCSIQ7A –AUGUST 2018 –REVISED DECEMBER 2021
6.5 Electrical Characteristics
VDD = 12 V, TA = TJ = –40°C to +125°C, CVDD = 1 µF, CREF = 1 µF, RAB = 22.6 kΩ, RCD = 22.6 kΩ, REF = 13.3 kΩ, RSUM
=
124 kΩ, RTMIN = 88.7 kΩ, RT = 59 kΩconnected between RT pin and 5-V voltage supply to set FSW = 100 kHz (FOSC = 200
kHz) (unless otherwise noted). All component designations are from 图8-3.
PARAMETER
TEST CONDITIONS
MIN
6.75
6.15
0.53
TYP
MAX
UNIT
UNDERVOLTAGE LOCKOUT (UVLO)
7.9
UVLO_RTH Start threshold
V
V
V
TA = 25°C
TA = 25°C
TA = 25°C
VDD = 5.2 V
7.3
6.7
0.6
7.2
Minimum operating voltage
UVLO_FTH
after start
0.75
UVLO_HYST Hysteresis
SUPPLY CURRENTS
270
10
IDD(off)
Startup current
µA
VDD = 5.2 V, TA = 25°C
150
5
IDD
Operating supply current
mA
TA = 25°C
VREF OUTPUT VOLTAGE
4.925
5.075
0 ≤IR ≤20 mA, 8 V ≤VDD ≤17 V
VREF
VREF total output range
V
0 ≤IR ≤20 mA, 8 V ≤VDD ≤17 V, TA =
25°C
5
ISCC
Short circuit current
VREF = 0 V
mA
–53
–23
108
SWITCHING FREQUENCY (½ OF INTERNAL OSCILLATOR FREQUENCY FOSC
)
92
FSW(nom)
Total range
kHz
TA = 25°C
TA = 25°C
100
97%
DMAX
Maximum duty cycle
95%
SYNCHRONIZATION
RT = 59 kΩbetween RT and GND, Input
pulses 200 kHz, D = 0.5 at SYNC
85
95
PHSYNC
Total range
°PH
RT = 59 kΩbetween RT and GND, Input
pulses 200 kHz, D = 0.5 at SYNC, TA = 25°C
90
RT = 59 kΩbetween RT and 5 V; –40 °C ≤
TJ ≤125°C
180
2.2
220
2.8
FSYNC
Total range
Pulse width
kHz
µs
TA = 25°C
200
2.5
TPW
TA = 25°C
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English Data Sheet: SLUSDB2
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