LTC3774
4
3774fc
For more information www.linear.com/LTC3774
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Note 2). V
IN
= 15V, V
RUN
= 5V unless otherwise specified.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
PG(HYST)
PGOOD Trip Level Hysteresis 2 %
INTV
CC
Linear Regulator
V
INTVCC
Linear Regulator Voltage 6V < V
IN
< 38V 5.3 5.5 5.7 V
V
LDO
INT INTV
CC
Load Regulation I
CC
= 0mA to 20mA 0.5 2 %
Oscillator and Phase-Locked Loop
f
OSC
Oscillator Frequency
V
PHSMD
= 0V
R
FREQ
< 23.2kΩ
R
FREQ
= 30.1kΩ
R
FREQ
= 47.5kΩ
R
FREQ
= 54.9kΩ
R
FREQ
= 75.0kΩ
Maximum Frequency
Minimum Frequency
l
l
540
1.2
150
250
600
750
1.05
660
0.2
kHz
kHz
kHz
kHz
MHz
MHz
MHz
I
FREQ
FREQ Pin Output Current V
FREQ
= 0.8V 19 20 21 µA
R
MODE/PLLIN
MODE/PLLIN Input Resistance 250 kΩ
V
MODE/PLLIN
PLLIN Input Threshold V
MODE/PLLIN
Rising
V
MODE/PLLIN
Falling
2
1.2
V
V
V
CLKOUT
Low Output Voltage
High Output Voltage
I
LOAD
= –500µA
I
LOAD
= 500µA
0.2
5.2
V
V
θ
2
– θ
1
Channel 1-2 Phase Delay V
PHSMD
= 0V
V
PHSMD
= 1/4 INTV
CC
V
PHSMD
= Float
V
PHSMD
= 3/4 INTV
CC
V
PHSMD
= INTV
CC
180
180
180
180
120
Deg
Deg
Deg
Deg
Deg
θ
CLKOUT
– θ
1
CLKOUT to Channel 1
Phase Delay
V
PHSMD
= 0V
V
PHSMD
= 1/4 INTV
CC
V
PHSMD
= Float
V
PHSMD
= 3/4 INTV
CC
V
PHSMD
= INTV
CC
60
60
90
45
240
Deg
Deg
Deg
Deg
Deg
θ
1
– θ
CLKIN
Channel 1 to CLKIN Phase Delay V
PHSMD
= 0V
V
PHSMD
= 1/4 INTV
CC
V
PHSMD
= Float
V
PHSMD
= 3/4 INTV
CC
V
PHSMD
= INTV
CC
0
90
0
0
0
Deg
Deg
Deg
Deg
Deg
PWM/P
WMEN Outputs
PWM PWM Output High Voltage I
LOAD
= 500µA
l
5.0 V
PWM Output Low Voltage I
LOAD
= –500µA
l
0.5 V
PWM Output Current in Hi-Z State
l
–5 5 µA
PWMEN PWMEN Output High Voltage I
LOAD
= 500µA
l
5.0 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: The LTC3774 is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTC3774E is guaranteed to meet performance specifications
from 0°C to 85°C operating 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 LTC3774I is guaranteed to meet performance specifications 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 package
thermal impedance and other environmental factors.
T
J
is calculated from the ambient temperature, T
A
, and power dissipation,
P
D
, according to the following formula:
LTC3774UHE: T
J
= T
A
+ (P
D
• 43°C/W)
Note 3: The LTC3774 is tested in a feedback loop that servos V
ITH
to a
specified voltage and measures the resultant V
FB
.
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 5: Guaranteed by design.
