Datasheet

   
   
SLUS419C − AUGUST 1999 − REVISED NOVEMBER 2001
5
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electrical characteristics T
A
= 0°C to 70°C for the UCC3850X, –40°C to 85°C for the UCC2850X,
T
A
= T
J
, VCC = 12 V, RT = 22 kΩ, CT = 330 pF (unless otherwise noted)
PFC gate driver
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
GT1 pull up resistance I
OUT
from −100 mA to –200 mA 5 12 Ω
GT1 pull down resistance I
OUT
= 100 mA 2 10 Ω
GT1 output rise time
C
LOAD
= 1 nF, R
LOAD
= 10 Ω
V
GT1
from 0.7 V to 9.0 V
25 50 ns
GT1 output fall time
C
LOAD
= 1 nF, R
LOAD
= 10 Ω
V
GT1
from 9.0 V to 0.7 V
10 50 ns
Maximum duty cycle 93% 95% 100%
Minimum controlled duty cycle f = 100 kHZ 2%
second stage undervoltage lockout (UVLO2)
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
PWM turn-on reference (UCCx8500/501) 6.30 6.75 7.30 V
Hysteresis (UCCx8500/501) 0.96 1.20 1.44 V
PWM turn−on reference (UCCx8502/503) 6.30 6.75 7.30 V
Hysteresis (UCCx8502/503) 2.4 3 3.6 V
second stage soft-start
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
SS2 charge current –7.3 –10 –12.5 µA
Input voltage (VERR) I
VERR
= 2 mA,UVLO = Low 300 mV
SS2 discharge current ENBL = High, UVLO = Low, SS2 = 2.5 V 3 10 mA
second stage duty cycle clamp
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Maximum duty cycle 44% 50%
second stage pulse-by-pulse current sense
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Current sense comparator threshold VERR = 2.5 V measured on ISENSE2 0.94 1.05 1.15 V
second stage overcurrent limit
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Peak current comparator threshold 1.15 1.30 1.45 V
Input bias current 50 nA
second stage gate driver
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
GT2 pull up resistance I
OUT
from −100 mA to –200 mA 5 12 Ω
GT2 pull down resistance I
OUT
= 100 mA 3 10 Ω
GT2 output rise time C
LOAD
= 1 nF,R
LOAD
= 10 Ω
V
GT2
from 0.7 V to 9.0 V
25 50 ns
GT2 output fall time C
LOAD
= 1 nF,R
LOAD
= 10 Ω
V
GT2
from 9.0 V to 0.7 V
25 50 ns
NOTES: 1. Ensured by design. Not production tested.
2. See Figure 6 for reference variation.
3. See Figure 5 for reference variation for VCC < 10.8 V .