UCC2897
SLUS591A − NOVEMBER 2003 − REVISED MARCH 2004
ELECTRICAL CHARACTERISTICS
VDD = 12 V(1), 1-µF capacitor from VDD to GND, 0.01-µF capacitor from VREF to GND, RT(on) = RT(off) = 75 kΩ, RDEL = 10 kΩ,
RSLOPE = 50 kΩ, −40
°C ≤
TA = TJ
≤
125°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
CURRENT SENSE
VLVL
VERR(max)
VCS
Current sense level shift voltage(3)
Maximum voltage error (clamped)(3)
Cycle-by-cycle
Hiccup mode
(3) Ensured by design. Not production tested.
Current sense threshold
VFB = 5 V
0.45
4.8
0.43
0.71
0.50
5.0
0.48
0.76
0.55
5.2
0.53
0.81
V
UNIT
FUNCTIONAL BLOCK DIAGRAM
VIN
1
VREF
VREF
IRDEL
RDEL
3
2.5 V
ICHG
CLOCK
Start
End
2.5 V
IDSCHG
CT
RTOFF
5
SYNC
VDD
S
R D
VREF
6
REF
GEN
IRDEL
+
Turn−on Delay
14
AUX
Q
Q
Turn−on Delay
VREF
1−DMAX
OUT
PWM
OFF
IRDEL
OUT
15
OUT
16 PVDD
LineUV
1.27 V
13 V/8 V
VDD
VREF
17
VDD
0.05
y
IRDEL
LineOV
1.27 V
18
LINEUV
0.05
y
IRDEL
20
N/C
N/C
2.5 V
2
19
LINEOV
RTON
4
0.5 V
SYNC
7
GND
8
VREF
5
y
ISLOPE
0.75 V
VREF
13
PGND
0.43
y
ICHG
4
y
R
12
Restart
R
VDD
VREF
LineUV
LineOV
UVLO & SS
Enable
11
FB
SS/SD
CS
9
CT
ISLOPE
1−DMAX
RSLOPE
10
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