Datasheet

3
LTC4221
4221fa
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
GATE(UP)
GATE n Output Current V
ON1
= V
ON2
= 2V, V
GATE n
= 0V ● –7 –9.5 –12 μA
I
GATE(DN)
GATE n Output Current V
ON1
= V
ON2
= 0.6V, V
GATE n
= 3.3V ● 75 100 125 μA
I
GATE(FSTDN)
GATE n Output Current UVLO with V
GATE n
= 3.3V or FAULT 16 mA
Latched with V
GATE n
= 3.3V
ΔV
GATE
External N-Channel Gate Drive V
GATE n
– V
CC1
for V
CC1
= 2.7V, V
CC2
= 1V ● 4.5 13 V
V
GATE n
– V
CC1
for V
CC1
= 3.3V, V
CC2
= 2.5V ● 516V
V
GATE n
– V
CC1
for V
CC1
= 5V, V
CC2
= 3.3V ● 816V
V
GATE n
– V
CC1
for V
CC1
= 12V, V
CC2
= 12V ● 718V
V
GATE(OV)
GATE n Overvoltage Lockout Threshold ● 0.4 0.5 V
I
ON(IN)
ON n Pin Input Current 0V ≤ V
ON n
≤ V
CC1
● ±0.01 ±1 μA
V
ON(RESET)
ON1 Reset Threshold V
ON1
Falling ● 0.375 0.4 0.425 V
ΔV
ON(RESETHYST)
ON1 Reset Threshold Hysteresis 25 mV
V
ON(OFF)
ON n Off Threshold High to Low, GATE n Turns Off by 100μA ● 0.796 0.821 0.846 V
Pull-Down
ΔV
ON(OFFHYST)
ON n Off Threshold Hysteresis 30 mV
I
FB(IN)
FB n Input Current 0V ≤ V
FB n
≤ V
CC n
● ±0.01 ±1 μA
V
FB(UV)
FB n Undervoltage Threshold FB n Falling ● 0.605 0.617 0.629 V
ΔV
FB(UVHYST)
FB n Undervoltage Threshold Hysteresis 3 mV
ΔV
FB(LREG)
FB n Threshold Line Regulation 2.7V ≤ V
CC1
≤ 13.5V 2 mV
V
FB(OV)
FB n Overvoltage Threshold FB n Rising ● 0.805 0.822 0.838 V
I
FILTER(UP)
FILTER Pull-Up Current During Current Fault Condition ● –80 –105 –132 μA
I
FILTER(DN)
FILTER Pull-Down Current During Normal Cycle ● 1.15 1.8 2.45 μA
V
FILTER(TH)
FILTER Threshold Latched Off Threshold, FILTER Rising ● 1.18 1.24 1.30 V
ΔV
FILTER(HYST)
FILTER Threshold Hysteresis 105 mV
I
TMR(UP1)
TIMER Pull-Up Current 1 Initial Timing Cycle ● –1.2 –1.9 –2.6 μA
I
TMR(UP2)
TIMER Pull-Up Current 2 Start-Up Cycle ● –15 –20 –25 μA
I
TMR(FSTDN)
TIMER Pull-Down Current V
TIMER
= 1.5V, End of Initial Timing Cycle 9 mA
V
TMR(H)
TIMER High Threshold TIMER Rising ● 1.172 1.234 1.27 V
V
TMR(L)
TIMER Low Threshold TIMER Falling ● 0.1 0.4 0.5 V
I
FAULT(UP)
FAULT Pull-Up Current ● –2.5 –3.8 –5 μA
V
FAULT(TH)
FAULT Threshold FAULT Falling ● 0.791 0.816 0.841 V
ΔV
FAULT(HYST)
FAULT Hysteresis 35 mV
V
FAULT(OL)
FAULT Output Low Voltage I
FAULT
= 1.6mA, V
CC1
= 5V ● 0.14 0.4 V
I
PWRGD(LK)
PWRGD n Leakage Current V
PWRGD n
= V
CC1
, V
FB n
= 0.7V, Normal Cycle ● ±0.01 ±10 μA
V
PWRGD(OL)
PWRGD n Output Low Voltage I
PWRGD n
= 1.6mA, V
CC1
= 5V, V
FB n
= 0V, ● 0.14 0.4 V
Normal Cycle
t
P(FC-GATE)
Fast Comparator Trip to GATE n V
SENSE n
= V
CC n
to (V
CC n
– 200mV) Step ● 1 1.5 μs
Discharging
t
P(SC-FAULT)
Slow Comparator Trip to FILTER V
SENSE n
= V
CC n
to (V
CC n
– 50mV) Step. ● 15 35 μs
High and FAULT Latched FILTER Open
The ● indicates specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC1
= 5V, V
CC2
= 3.3V, unless otherwise noted.
ELECTRICAL CHARACTERISTICS