Datasheet

LTC3861-1
4
38611fa
For more information www.linear.com/LTC3861-1
elecTrical characTerisTics
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
J
= 25°C (Note 3). V
CC
= 5V, V
RUN1,2
= 5V, V
FREQ
= 5V, V
CLKIN
= 0V,
V
FB
= 0.6V, f
OSC
= 0.6MHz, unless otherwise specified.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
ISENSE
SENSE Pin Input Current V
CM
= 1.5V 100 nA
V
OS
Current Sense Input Referred Offset –40°C to 125°C
l
–1.25 1.25 mV
Oscillator and Phase-Locked Loop
f
OSC
Oscillator Frequency V
CLKIN
= 0V
V
FREQ
= 0V
V
FREQ
= 5V
l
l
360
540
400
600
440
660
kHz
kHz
V
CLKIN
= 5V
R
FREQ
< 24.9k
R
FREQ
= 36.5k
R
FREQ
= 48.7k
R
FREQ
= 64.9k
R
FREQ
= 88.7k
200
600
1
1.45
2.1
kHz
kHz
MHz
MHz
MHz
Maximum Frequency
Minimum Frequency
3
0.25
MHz
MHz
I
FREQ
FREQ Pin Output Current V
FREQ
= 0.8V 18.5 20 21.5 µA
t
CLKIN(HI)
CLKIN Pulse Width High V
CLKIN
= 0V to 5V 100 ns
t
CLKIN(LO)
CLKIN Pulse Width Low V
CLKIN
= 0V to 5V 100 ns
R
CLKIN
CLKIN Pull-Up Resistance 13 kΩ
V
CLKIN
CLKIN Input Threshold V
CLKIN
Falling
V
CLKIN
Rising
1.2
2
V
V
V
FREQ
FREQ Input Threshold V
CLKIN
= 0V
V
FREQ
Falling
V
FREQ
Rising
1.5
2.5
V
V
V
OL(CLKOUT)
CLKOUT Low Output Voltage I
LOAD
= –500µA 0.2 V
V
OH(CLKOUT)
CLKOUT High Output Voltage I
LOAD
= 500µA V
CC
– 0.2 V
θ
2
-θ
1
Channel 1-to-Channel 2 Phase Relationship V
PHSMD
= 0V
V
PHSMD
= Float
V
PHSMD
= V
CC
180
180
120
Deg
Deg
Deg
θ
CLKOUT
-θ
1
CLKOUT-to-Channel 1 Phase Relationship V
PHSMD
= 0V
V
PHSMD
= Float
V
PHSMD
= V
CC
60
90
240
Deg
Deg
Deg
PWM/PWMEN Outputs
PWM PWM Output High Voltage I
LOAD
= 500µA
l
4.5 V
PWM Output Low Voltage I
LOAD
= –500µA
l
0.5 V
PWM Output Current in Hi-Z State ±5 µA
PWM Maximum Duty Cycle 91.5 %
PWMEN PWMEN Output High Voltage I
LOAD
= 1mA
l
4.5 V
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: 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
• 34°C/W)
Note 3: The LTC3861-1 is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTC3861-1E is guaranteed to meet performance
specifications from 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 LTC3861-1I is guaranteed over the full –40°C to 125°C
operating junction temperature range. The maximum ambient temperature
consistent with these specifications is determined by specific operating
conditions in conjunction with board layout, the rated package thermal
resistors and other environmental factors.
Note 4: Guaranteed by design.