Datasheet

UCC25705, UCC25706, UCC35705, UCC35706
HIGH-SPEED VOLTAGE MODE PULSE WIDTH MODULATOR
SLUS473B -- NOVEMBER 1999 -- REVISED OCTOBER 2010
3
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electrical characteristics, V
DD
=11V,V
IN
=30V,R
T
=47k,R
DISCH
= 400 k, R
FF
=14k,C
T
= 220 pF,
C
VDD
=0.1μF, and no load on the outputs, 0°C ≤ T
A
≤ 70°C for the UCC3570x and --40°C ≤ T
A
≤ 85°C
for the UCC2570x, T
A
=T
J
, (unless otherwise specified)
line sense section
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Low line comparator threshold 0.95 1.00 1.05 V
Input bias current (VFF) –100 100 nA
oscillator section
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Frequency VFF = 1.2 V to 4.8 V 0.9 1.0 1.1 MHz
C
T
p
e
a
k
v
o
l
t
a
g
e
VFF = 1.2 V, See Note 1 1.2 V
CT peak voltage
VFF = 4.8 V, See Note 1 4.8 V
CT valley voltage SeeNote1 0 V
NOTE 1: Ensured by design. Not production tested.
current limit section
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Input bias current 0.2 –0.2 –1 μA
Current limit threshold 180 200 220 mV
Propagation delay, ILIM to OUT 50 mV overdrive 25 35 ns
pulse width modulator section
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
FB input impedance V
FB
=3V 30 50 90 kΩ
Minimum duty cycle V
FB
<2V 0 %
M
a
i
m
m
d
t
c
c
l
e
V
FB
=V
DD
,F
OSC
=1MHz 70 75 80 %
Maximum duty cycle
V
DISCH
=0V, F
OSC
=1MHz 93 %
PWM gain VFF = 2.5 V, MODE = 1 12 %/V
Propagation delay, PWM to OUT 65 120 ns
output section
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
VOH I
OUT
=–5mA, V
DD
– output 0.3 0.6 V
VOL I
OUT
=5mA 0.15 0.4 V
Rise time C
LOAD
=50pF 10 25 ns
Fall time C
LOAD
=50pF 10 25 ns