LTC3731 Linear Technology, LTC3731 Datasheet - Page 4

• Manufacturer Part Number: LTC3731
• Description: Synchronous Buck Switching Regulator Controller
• Manufacturer: Linear Technology

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ELECTRICAL CHARACTERISTICS
LTC3731
SYMBOL
Power Good Output Indication
V
I
I
V
V
V
Oscillator and Phase-Locked Loop
f
f
f
V
R
I
R
CLKOUT
Differential Amplifier
A
V
CM
CMRR
I
GBP
SR
V
R
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: T
dissipation P
Note 3: The IC is tested in a feedback loop that includes the differential
amplifier loaded with 100µA to ground driving the error amplifier and
servoing the resultant voltage to the midrange point for the error amplifier
(V
temperature range, otherwise specifications are at T
4
PGOOD
PGOOD
NOM
LOW
HIGH
PLLFLTR
CL
PGL
PGTHNEG
PGTHPOS
PGDLY
PLLTH
PLLIN
RELPHS
V
OS
O(MAX)
IN
ITH
LTC3731CG/LTC3731IG: T
LTC3731CG/LTC3731IG: T
LTC3731CUH/LTC3731IUH: T
= 1.2V).
J
is calculated from the ambient temperature T
D
according to the following formula:
PARAMETER
PGOOD Voltage Output Low
PGOOD Output Leakage
PGOOD/PHASMD Bias I
PGOOD Trip Thesholds
V
V
Power Good Fault Report Delay
Nominal Frequency
Lowest Frequency
Highest Frequency
PLLIN Input Threshold
PLLIN Input Resistance
Phase Detector Output Current
Controller 2-Controller 1 Phase
Controller 3-Controller 1 Phase
Controller 1 TG to CLKOUT Phase
Differential Gain
Input Offset Voltage Magnitude
Common Mode Input Voltage Range
Common Mode Rejection Ratio
Output Current Sourcing
Gain Bandwidth Product
Slew Rate
Maximum High Output Voltage
Input Resistance
DIFFOUT
DIFFOUT
Sinking Capability
Sourcing Capability
Ramping Negative
Ramping Positive
J
J
= T
= T
J
A
CASE
= T
+ (P
A
+ (P
+ (P
D
× 95°C/W)
D
D
× 34°C/W)
× 32°C/W)
A
CONDITIONS
I
I
V
HGOOD Goes Low After V
After V
V
V
V
Minimum Pulse Width > 100ns
f
f
PHASMD = 0V
PHASMD = 5V
IN
Input Referred; Gain = 1
0V < IN
I
R
I
Measured at IN
PGOOD
PGOOD
V
0 ≤ V
PLLIN
PLLIN
OUT
OUT
DIFFOUT
PLLFLTR
PLLFLTR
PLLFLTR
and power
L
PGOOD
+
= 2k
= IN
A
= 1mA
= 1mA
PHASMD/PG
< f
> f
= 25°C. V
EAIN
= 2mA, G Package
= 1.6mA, UH Package
+
–
= 5V, G Package
OSC
OSC
= IN
with Respect to Set Output Voltage,
= 1.2V
= 0V
= 2.4V
= 1.2V, I
is Forced Outside the PGOOD Thresholds
The
–
< 5V, I
+
●
Pin
≤ V
CC
OUT
denotes the specifications which apply over the full operating
= V
CC
OUT
= 1mA,
, UH Package
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 5: The minimum on-time condition corresponds to an inductor peak-
to-peak ripple current of ≥ 40% of I
considerations in the Applications Information Section).
Note 6: This IC includes overtemperature protection that is intended to
protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
RUN/SS
= 1mA, Input Referred
UVDLY
Delay
= 5V unless otherwise noted.
MAX
V
CC
0.995
MIN
360
190
600
–10
50
10
–7
0
(see minimum on-time
– 1.2 V
7
CC
1.000
TYP
400
225
680
120
240
–10
100
0.5
0.1
0.5
50
20
20
30
60
70
40
80
±3
1
2
5
– 0.8
10
1.005
MAX
–13
150
440
260
750
V
0.3
1.0
10
1
13
5
CC
UNITS
3731fa
MHz
V/µs
Deg
Deg
Deg
Deg
kHz
kHz
kHz
V/V
mV
mA
kΩ
kΩ
µA
µA
µA
µA
dB
µs
%
%
V
V
V
V
V