Datasheet

UCC28950
www.ti.com SLUSA16B –MARCH 2010–REVISED OCTOBER 2011
RECOMMENDED OPERATING CONDITIONS
over operating free-air temperature range (unless otherwise noted)
MIN TYP MAX UNIT
Supply voltage range, V
DD
8 12 17 V
Operating junction temperature range -40 125 °C
Converter switching frequency setting range, F
SW(nom)
50 1000 kHz
Programmable delay range between OUTA, OUTB and OUTC, OUTD set by
30 1000
resistors DELAB and DELCD and parameter K
A
(1)
ns
Programmable delay range between OUTA, OUTF and OUTB, OUTE set by
30 1400
resistor DELEF, and parameter K
EF
(1)
Programmable DCM range as percentage of voltage at CS
(1)
5% 30%
Programmable T
MIN
range 100 800 ns
(1) Verified during characterization only.
ELECTRICAL CHARACTERISTICS
(1)
V
DD
= 12 V, T
A
= T
J
= -40°C to 125°C, C
VDD
= 1 µF, C
REF
= 1 µF, R
AB
= 22.6 kΩ, R
CD
= 22.6 kΩ , R
EF
= 13.3 kΩ, RSUM = 124
kΩ, RMIN = 88.7 kΩ, RT = 59 kΩ connected between RT pin and 5-V voltage supply to set F
SW
= 100 kHz (F
OSC
= 200 kHz)
(unless otherwise noted). All component designations are from the Typical Application Diagram.
PARAMETER TEST CONDITION MIN TYP MAX UNITS
Under Voltage Lockout (UVLO)
UVLO_R
Start threshold 6.75 7.3 7.9
TH
UVLO_F Minimum operating voltage
6.15 6.7 7.2 V
TH after start
UVLO_H
Hysteresis 0.53 0.6 0.75
YST
Supply Currents
I
DD(off)
Startup current V
DD
is 5.2 V 150 270 µA
I
DD
Operating supply current 5 10 mA
VREF Output Voltage
V
REF
VREF total output range 0 ≤ IR ≤ 20 mA; V
DD
= from 8 V to 17 V 4.925 5 5.075 V
ISCC Short circuit current VREF = 0 V -53 -23 mA
Switching Frequency (½ of internal oscillator frequency F
OSC
)
F
SW(nom)
Total range 92 100 108 KHz
D
MAX
Maximum duty cycle 95% 97%
Synchronization
RT = 59 kΩ between RT and GND; Input pulses
PH
SYNC
Total range 85 90 95 °PH
200 kHz, D = 0.5 at SYNC
RT = 59 kΩ between RT and 5 V; -40 °C ≤ T
J
≤
F
SYNC
Total range 180 200 220 kHz
125°C
T
PW
Pulse width 2.2 2.5 2.8 µs
(1) Typical values for T
A
= 25°C
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