LTC3890-3 Datasheet, PDF (4/40 Pages) Linear Technology – 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller

LTC3890-3
Electrical Characteristics The l denotes the specifications which apply over the full operating junction
temperature range, otherwise specifications are at T_A = 25°C. V_IN = 12V, V_RUN1,2 = 5V, EXTV_CC = 0V unless otherwise noted. (Note 2)
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
TG/BG t_1D Top Gate Off to Bottom Gate On Delay C_LOAD = 3300pF Each Driver
Synchronous Switch-On Delay Time
30
ns
BG/TG t_1D Bottom Gate Off to Top Gate On Delay C_LOAD = 3300pF Each Driver
Top Switch-On Delay Time
30
ns
t_ON(MIN)
Minimum On-Time
(Note 7)
95
ns
INTV_CC Linear Regulator
V_INTVCCVIN
V_LDOVIN
V_INTVCCEXT
V_LDOEXT
V_EXTVCC
Internal V_CC Voltage
INTV_CC Load Regulation
Internal V_CC Voltage
INTV_CC Load Regulation
EXTV_CC Switchover Voltage
6V < V_IN < 60V, V_EXTVCC = 0V
I_CC = 0mA to 50mA, V_EXTVCC = 0V
6V < V_EXTVCC < 13V
I_CC = 0mA to 50mA, V_EXTVCC = 8.5V
EXTV_CC Ramping Positive
4.85
5.1
5.35
V
0.7
1.1
%
4.85
5.1
5.35
V
0.6
1.1
%
4.5
4.7
4.9
V
V_LDOHYS
EXTV_CC Hysteresis
250
mV
Oscillator and Phase-Locked Loop
f_25kΩ
f_65kΩ
f_105kΩ
Programmable Frequency
Programmable Frequency
Programmable Frequency
R_FREQ = 25k, PLLIN/MODE = DC Voltage
R_FREQ = 65k, PLLIN/MODE = DC Voltage
R_FREQ = 105k, PLLIN/MODE = DC Voltage
105
kHz
375
440
505
kHz
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
PGOOD1 Output
PLLIN/MODE = External Clock
l 75
850
kHz
V_PGL
I_PGOOD
PGOOD1 Voltage Low
PGOOD1 Leakage Current
I_PGOOD = 2mA
V_PGOOD = 5V
0.2
0.4
V
±1
µA
V_PG
PGOOD1 Trip Level
V_FB with Respect to Set Regulated Voltage
V_FB Ramping Negative
Hysteresis
–13
–10
–7
%
2.5
%
V_FB with Respect to Set Regulated Voltage
V_FB Ramping Positive
Hysteresis
7
10
13
%
2.5
%
t_PG
Delay for Reporting a Fault
25
µs
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Ratings for extended periods may affect device reliability and
lifetime.
Note 2: The LTC3890-3 is tested under pulsed load condition such that
T_J ≈ T_A.The LTC3890E-3 is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 125°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3890I-3 is guaranteed
over the –40°C to 125°C operating junction temperature range, the
LTC3890H-3 is guaranteed over the –40°C to 150°C operating junction
temperature range and the LTC3890MP-3 is tested and guaranteed over
the –55°C to 150°C operating junction temperature range.
High junction temperatures degrade operating lifetimes; operating lifetime
is derated for junction temperatures greater than 125°C. Note that the
maximum ambient temperature consistent with these specifications is
determined by specific operating conditions in conjunction with board layout,
the rated package thermal impedance and other environmental factors.
Note 3: T_J is calculated from the ambient temperature T_A and power
dissipation P_D according to the following formula:
T_J = T_A + (P_D • 90°C/W)
Note 4: The LTC3890-3 is tested in a feedback loop that servos V_ITH1,2 to
a specified voltage and measures the resultant V_FB. The specification at
85°C is not tested in production and is assured by design, characterization
and correlation to production testing at other temperatures (125°C for the
LTC3890E-3/LTC3890I-3, 150°C for the LTC3890H-3/LTC3890MP-3). For
the LTC3890MP-3, the specification at –40°C is not tested in production
and is assured by design, characterization and correlation to production
testing at –55°C.
Note 5: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See the Applications information section.
Note 6: Rise and fall times are measured using 10% and 90% levels. Delay
times are measured using 50% levels.
Note 7: The minimum on-time condition is specified for an inductor peak-
to-peak ripple current ≥ of I_MAX (See Minimum On-Time Considerations in
the Applications Information section).
38903f
4
For more information www.linear.com/3890-3