Datasheet

3
LTC3834-1
38341f
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
LOADREG
Output Voltage Load Regulation (Note 4)
Measured in Servo Loop; I
TH
Voltage = 1.2V to 0.7V ● 0.1 0.5 %
Measured in Servo Loop; I
TH
Voltage = 1.2V to 2V ● –0.1 –0.5 %
g
m
Transconductance Amplifier g
m
I
TH
= 1.2V; Sink/Source 5μA (Note 4) 0.5 mmho
I
Q
Input DC Supply Current (Note 5)
Sleep Mode RUN = 5V, V
FB
= 0.83V (No Load) 30 50 μA
Shutdown V
RUN
= 0V 4 10 μA
UVLO Undervoltage Lockout V
IN
Ramping Down ● 3.7 4 V
V
OVL
Feedback Overvoltage Lockout Measured at V
FB
Relative to Regulated V
FB
81012 %
I
SENSE
Sense Pins Total Source Current V
SENSE
– = V
SENSE
+ = 0V –220 μA
DF
MAX
Maximum Duty Factor In Dropout 98 99.4 %
I
TRACK/SS
Soft-Start Charge Current V
TRACK
= 0V 0.85 1.1 1.45 μA
V
RUN
ON RUN Pin ON Threshold V
RUN1,
V
RUN2
Rising 0.5 0.7 0.9 V
V
SENSE(MAX)
Maximum Current Sense Threshold V
FB
= 0.7V, V
SENSE
– = 3.3V ● 85 100 115 mV
TG Transition Time: (Note 6)
TG1, 2 t
r
Rise Time C
LOAD
= 3300pF 50 90 ns
TG1, 2 t
f
Fall Time C
LOAD
= 3300pF 50 90 ns
BG Transition Time: (Note 6)
BG1, 2 t
r
Rise Time C
LOAD
= 3300pF 40 90 ns
BG1, 2 t
f
Fall Time C
LOAD
= 3300pF 40 80 ns
TG/BG t
1D
Top Gate Off to Bottom Gate On Delay C
LOAD
= 3300pF 70 ns
Synchronous Switch-On Delay Time
BG/TG t
2D
Bottom Gate Off to Top Gate On Delay C
LOAD
= 3300pF 70 ns
Top Switch-On Delay Time
t
ON(MIN)
Minimum On-Time (Note 7) 200 ns
INTV
CC
Linear Regulator
V
INTVCCVIN
Internal V
CC
Voltage 8.5V < V
IN
< 30V 5.0 5.25 5.5 V
V
LDOVIN
INTV
CC
Load Regulation I
CC
= 0mA to 20mA 0.2 1.0 %
Oscillator and Phase-Locked Loop
f
NOM
Nominal Frequency V
PLLLPF
= No Connect 360 400 440 kHz
f
LOW
Lowest Frequency V
PLLLPF
= 0V 220 250 280 kHz
f
HIGH
Highest Frequency V
PLLLPF
= INTV
CC
475 530 580 kHz
f
SYNCMIN
Minimum Synchronizable Frequency PLLIN/MODE = External Clock; V
PLLLPF
= 0V 115 140 kHz
f
SYNCMAX
Maximum Synchronizable Frequency PLLIN/MODE = External Clock; V
PLLLPF
= 2V 650 800 kHz
I
PLLLPF
Phase Detector Output Current
Sinking Capability f
PLLIN/MODE
< f
OSC
–5 μA
Sourcing Capability f
PLLIN/MODE
> f
OSC
5 μA
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, V
RUN
= 5V unless otherwise noted.
ELECTRICAL CHARACTERISTICS
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 LTC3834E-1 is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 85°C operating temperature
range are assured by design, characterization and correlation with statistical
process controls. The LTC3834I-1 is guaranteed to meet performance
specifications over the –40°C to 85°C operating temperature range.
Note 3: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formulas:
LTC3834GN-1: T
J
= T
A
+ (P
D
• 90°C/W)
LTC3834DHC-1: T
J
= T
A
+ (P
D
• 43.5°C/W)
Note 4: The LTC3834-1 is tested in a feedback loop that servos V
ITH
to a
specified voltage and measures the resultant V
FB.
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
MAX
(see Minimum On-Time
Considerations in the Applications Information section).