UCC28250 Datasheet, PDF (4/50 Pages) Texas Instruments – Advanced PWM Controller With Pre-Bias Operation

UCC28250
SLUSA29B – APRIL 2010 – REVISED OCTOBER 2010
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ELECTRICAL CHARACTERISTICS⁽¹⁾ (continued)
VDD = 12 V, 1-µF capacitor from VDD and VREF to GND, T_A = T_J = -40°C to 125°C, RT = 75 kΩ connected to ground to set
F_SW = 200 kHz (unless otherwise noted).
PARAMETER
TEST CONDITION
MIN
TYP MAX UNITS
Oscillator
F_SW(nom)
F_{SW(min_sync)}
Nominal switching frequency
at OUTA or OUTB set by RT RT/SYNC = 75 kΩ, R_SP = 20 kΩ
resistor
Minimum switching frequency
at OUTA or OUTB set by
external sync frequency
f_RT/SYNC = 100 kHz
185
200
215
kHz
85
F_{SW(max_sync)}
Maximum switching
frequency at OUTA or OUTB
set by external sync
frequency
f_RT/SYNC = 2.5 MHz
1.15
MHz
External synchronization
signal high
External synchronization
signal low
1
V
0.2
Voltage Reference
V_VREF
Output voltage
V_DD = from 7 V to 17 V, I_VREF = 2 mA
0 < I_REF < 10 mA
Short circuit current
V_REF = 3 V, T_J = 25°C
Current Sense, Cycle-by-Cycle Current Limit With Hiccup
3.22 3.30 3.38
V
3.22 3.30 3.38
12
25
40 mA
V_ILIM
T_PDILIM
ILIM cycle-by-cycle threshold
Propagation delay from ILIM
to OUTA and OUTB outputs
Exclude leading edge blanking
0.495 0.502 0.509 V
15
25
36 ns
T_BLANK
leading edge blanking
Current limit shutdown delay
timing program current
Hiccup timing program
current
Measured at HICC pin
Measured at HICC pin
40
60
90 ns
55
75
95
µA
2
2.7
3.5
V_{HICC_SD}
Current limit shutdown delay
timer threshold at HICC
0.55 0.60 0.65
V_{HICC_PU}
V_{HICC_RST}
V_CS(max)
HICC pull-up threshold
Hiccup restart threshold
RAMP/CS clamp voltage
10-V ramp charging voltage source with 40-kΩ
current limiting resistor
2.3
2.4
2.5
V
0.25 0.30 0.35
3.5
4.0
4.5
4
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