Datasheet

LTC3891
4
3891fa
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating junction
temperature range, otherwise specifications are at T
A
= 25°C (Note 2), V
IN
= 12V, V
RUN
= 5V, EXTV
CC
= 0V unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Gate Driver
TG Pull-Up On-Resistance
Pull-Down On-Resistance
2.5
1.5
Ω
Ω
BG Pull-Up On-Resistance
Pull-Down On-Resistance
2.4
1.1
Ω
Ω
TG t
r
TG t
f
TG Transition Time:
Rise Time
Fall Time
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
25
16
ns
ns
BG t
r
BG t
f
BG Transition Time:
Rise Time
Fall Time
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
25
13
ns
ns
TG/BG t
1D
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
C
LOAD
= 3300pF 30 ns
BG/TG t
1D
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time
C
LOAD
= 3300pF 30 ns
t
ON(MIN)
Minimum On-Time (Note 7) 95 ns
INTV
CC
Linear Regulator
V
INTVCCVIN
Internal V
CC
Voltage 6V < V
IN
< 60V, V
EXTVCC
= 0V 4.85 5.1 5.35 V
V
LDOVIN
INTV
CC
Load Regulation I
CC
= 0mA to 50mA, V
EXTVCC
= 0V 0.7 1.1 %
V
INTVCCEXT
Internal V
CC
Voltage 6V < V
EXTVCC
< 13V 4.85 5.1 5.35 V
V
LDOEXT
INTV
CC
Load Regulation I
CC
= 0mA to 50mA,
V
EXTVCC
= 8.5V
0.6 1.1 %
V
EXTVCC
EXTV
CC
Switchover Voltage I
CC
= 0mA to 50mA,
EXTV
CC
Ramping Positive
4.5 4.7 4.9 V
V
LDOHYS
EXTV
CC
Hysteresis 250 mV
Oscillator and Phase-Locked Loop
f
25kΩ
Programmable Frequency R
FREQ
= 25k;
PLLIN/MODE = DC Voltage
105 kHz
f
65kΩ
Programmable Frequency R
FREQ
= 65k;
PLLIN/MODE = DC Voltage
375 440 505 kHz
f
105kΩ
Programmable Frequency R
FREQ
=105k;
PLLIN/MODE = DC Voltage
835 kHz
f
LOW
Low Fixed Frequency V
FREQ
= 0V;
PLLIN/MODE = DC Voltage
320 350 380 kHz
f
HIGH
High Fixed Frequency V
FREQ
= INTV
CC
;
PLLIN/MODE = DC Voltage
485 535 585 kHz
f
SYNC
Synchronizable Frequency PLLIN/MODE = External Clock
l
75 750 kHz
PGOOD1 Output
V
PGL
PGOOD Voltage Low I
PGOOD
= 2mA 0.2 0.4 V
I
PGOOD
PGOOD Leakage Current V
PGOOD
= 5V ±1 µA
V
PG
PGOOD Trip Level V
FB
with Respect to Set Regulated Voltage
V
FB
Ramping Negative –13 –10 –7 %
Hysteresis 2.5 %
V
FB
Ramping Positive 7 10 13 %
Hysteresis 2.5 %
t
PG
Delay for Reporting a Fault 25 µs