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ELECTRICAL CHARACTERISTICS
junction temperature range, otherwise specifications are at T
SYMBOL
PARAMETER
INTV
Linear Regulator
CC
V
Internal V
Voltage
INTVCC
CC
V
INT
INTV
Load Regulation
LDO
CC
V
EXTV
Switchover Voltage
EXTVCC
CC
V
EXT
EXTV
Voltage Drop
LDO
CC
V
EXTV
Hysteresis
LDOHYS
CC
Oscillator and Phase-Locked Loop
f
Nominal Frequency
NOM
f
Lowest Frequency
LOW
f
Highest Frequency
HIGH
R
MODE/PLLIN Input Resistance
MODE/PLLIN
I
Frequency Setting Current
FREQ
CLKOUT
Phase (Relative to Controller 1)
CLK High
Clock Output High Voltage
CLK Low
Clock Output Low Voltage
V
PGOOD Voltage Low
PGL
I
PGOOD Leakage Current
PGOOD
V
PGOOD Trip Level, Either Controller V
PG
On-Chip Driver
TG R
TG Pull-Up R
UP
TG R
TG Pull-Down R
DOWN
BG R
BG Pull-Up R
UP
BG R
BG Pull-Down R
DOWN
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LTC3875 is tested under pulsed load conditions such that
T
≈ T
. The LTC3875E is guaranteed to meet specifications from
J
A
0°C to 85°C junction temperature. Specifications over the –40°C to
125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LTC3875I is guaranteed over the full –40° to 125° operating junction
temperature range. 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.
CONDITIONS
6V < V
IN
I
= 0mA to 20mA
CC
EXTV
Ramping Positive
CC
I
= 20mA, V
CC
V
= 1.2V
FREQ
V
= 0V
FREQ
V
≥ 2.4V
FREQ
PHASMD = GND
PHASMD = FLOAT
PHASMD = INTV
V
= 5.5V
INTVCC
I
= 2mA
PGOOD
V
= 5.5V
PGOOD
+
with Respect to Set Output Voltage
OSNS
+
V
OSNS
+
V
OSNS
TG High
DS(ON)
TG Low
DS(ON)
BG High
DS(ON)
BG Low
DS(ON)
For more information
The
denotes the specifications which apply over the specified operating
l
= 25°C (Note 2). V
= 15V, V
A
IN
< 38V
= 5.5V
EXTVCC
CC
Ramping Negative
Ramping Positive
Note 3: T
is calculated from the ambient temperature, T
J
dissipation, P
, according to the formula:
D
T
= T
+ (P
• θ
J
A
D
where θ
= 44°C/W for the 5mm × 5mm QFN and θ
JA
the 6mm × 6mm QFN.
Note 4: The LTC3875 is tested in a feedback loop that servos V
specified voltage and measures the resultant V
Note 5: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
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 ≥40% of I
Considerations in the Applications Information section).
Note 8: Guaranteed by design.
www.linear.com/LTC3875
LTC3875
= 5V unless otherwise noted.
RUN1,2
MIN
TYP
5.3
5.5
0.5
4.5
4.7
l
50
200
450
500
220
250
650
720
250
9.5
10
60
90
120
4.5
5.5
0.1
–7.5
7.5
2.6
1.5
2.4
1.1
°C/W)
JA
JA
OSNS1,2
(see Minimum On-Time
MAX
MAX
UNITS
5.7
V
2.0
%
V
100
mV
mV
550
kHz
270
kHz
790
kHz
kΩ
10.5
µA
Deg
Deg
Deg
V
0.2
V
0.3
V
±2
µA
%
%
Ω
Ω
Ω
Ω
, and power
A
= 33°C/W for
to a
ITH1,2
+
.
3875fb
5
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