Datasheet

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ELECTRICAL CHARACTERISTICS (Continued)
(2) Gain constant.
( )
( )
( )
2
1 5
IAC VAO
VRMS MOUT
I V . V
K
V I
´ -
=
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UC1854A
UC2854A, UC2854B
UC3854A, UC3854B
SLUS329E – MONTH 2003 – REVISED JANUARY 2008
V
CC
= 18 V, R
T
= 8.2 k Ω , C
T
= 1.5 nF, V
PKLMT
= 1 V, V
VRMS
= 1.5 V, I
IAC
= 100 µ A, I
ISENSE
= 0 V, V
CAO
= 3.5 V, V
VAO
= 5 V,
V
VSENSE
= 3 V, – 40 ° C < T
A
< 85 ° C for the UC2854A and UC2854B, and 0 ° C < T
A
< 70 ° C for the UC3854A and UC3854B,
and T
A
= T
J
(unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
OSCILLATOR
Initial accuracy T
A
= 25 ° C 85 100 115 kHz
Voltage stability 12 V ≤ V
CC
≤ 18 V 1%
Total variation Line, temperature 80 120 kHz
Ramp amplitude (peak-to-peak) 4.9 5.9 V
Ramp valley voltage 0.8 1.3 V
ENABLE/SOFT-START/CURRENT LIMIT
Enable threshold voltage 2.35 2.55 2.80 V
Enaable hysteresis V
FAULT
= 2.5 V 500 600 mV
Enable input bias current V
ENA
= 0 V – 2 – 5 µ A
Propagation delay to disable time
(1)
Enable overdrive = 100 mV 300 ns
Soft-start charge current V
SS
= 2.5 V 10 14 24 µ A
Peak limit offset voltage – 15 15 mV
Peak limit offset current V
PKLMIT
= – 0.1 V – 200 – 100 µ A
Peak limit propagation delay time
(1)
150 ns
MULTIPLIER
I
AC
= 100 µ A, V
RMS
= 1 V,
Output current, I
A
limited – 220 – 200 – 170 µ A
R
SET
= 10 k Ω
Output current, zero I
AC
= 0 µ A, R
SET
= 10 k Ω – 2.0 – 0.2 2.0 µ A
Output current, power limited V
RMS
= 1.5 V Va = 6 V – 230 – 200 – 170 µ A
V
RMS
= 1.5 V Va = 2 V – 22
V
RMS
= 1.5 V Va = 5 V – 156
Output current µ A
V
RMS
= 5 V Va = 2 V – 2
V
RMS
= 5 V Va = 5 V – 14
Gain constant
(2)
V
RMS
= 1.5 V Va = 6 V, T
A
= 25 ° C – 1.1 – 1.0 – 0.9 A/A
GATE DRIVER
V
OH
High-level output voltage I
OUT
= – 200 mA, V
CC
= 15 V 12.0 12.8 V
V
OL
Low-level output voltage I
OUT
= 200 mA 1.0 2.2 V
I
OUT
= 10 mA 300 500 mV
Low-level UVLO voltage I
OUT
= 50 mA, V
CC
= 0 V 0.9 1.5 V
Output rise time
(1)
C
LOAD
= 1 nF 35 ns
Output fall time
(1)
C
LOAD
= 1 nF 35 ns
Output peak current
(1)
C
LOAD
= 10 nF 1.0 A
(1) Ensured by design. Not production tested.
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Product Folder Link(s): UC1854A UC2854A, UC2854B UC3854A, UC3854B