Datasheet

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SLUS542F − OCTOBER 2003 − REVISED JULY 2009
4
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ELECTRICAL CHARACTERISTICS
V
DD
= 12 V
(1)
, 1-µF capacitor from VDD to GND, 0.01-µF capacitor from VREF to GND, R
ON
= R
OFF
= 75 kΩ, R
DEL
= 10 kΩ,
R
SLOPE
= 50 kΩ, −40 °C ≤ T
A
= T
J
≤ 125°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS MIN TYP MAX UNIT
Voltage Reference
V
REF
Reference voltage
T
J
= 25°C 4.85 5.00 5.15
V
V
REF
Reference voltage
0 A < I
REF
< 5 mA, over temperature
4.75 5.00 5.25
V
I
SC
Short circuit current REF = 0 V, T
J
= 25°C −20 −11 −8 mA
INTERNAL SLOPE COMPENSATION
m Slope
(3)
FB = High -10%
R
CS
R
SLOPE
+10%
OSCILLATOR
f
OSC
Oscillator frequency T
J
= 25°C 237 250 263
kHz
Total variation
−40 °C < T
J
125°C; 8.5 V < 14.5 V
225
270
kHz
Total variation −40 °C < T
J
125°C; 8.5 V < 14.5 V 225 270
kHz
V
P_P
Oscillator amplitude (peak-to-peak) 2 V
SYNCHRONIZATION
V
SYNCH
SYNC theshold voltage 1.6 2.3 3.0 V
t
DEL
SYNC-to-output delay 50 ns
PWM
Maximum duty cycle 66% 70% 74%
Minimum duty cycle 0%
PWM offset CS = 0 V 0.43 0.50 0.61 V
CURRENT SENSE
V
LVL
Current sense level shift voltage 0.40 0.50 0.60
V
ERR(max)
Maximum voltage error (clamped) 4.8 5.0 5.2
V
CS
Current sense threshold
UCC2891
UCC2893
0.71 0.75 0.79
V
V
CS
Current sense threshold
UCC2892
UCC2894
1.23 1.27 1.31
(1)
Set VDD above the start threshold before setting at 12 V.
(2)
Does not include current of the external oscillator network.