Datasheet

LTC3835-1
3
38351fc
ELECTRICAL CHARACTERISTICS
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
IN
= 12V, V
RUN
= 5V unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loop
V
FB
Regulated Feedback Voltage (Note 4); I
TH
Voltage = 1.2V
l
0.792 0.800 0.808 V
I
VFB
Feedback Current (Note 4) –5 –50 nA
V
REFLNREG
Reference Voltage Line Regulation V
IN
= 4V to 30V (Note 4) 0.002 0.02 %/V
V
LOADREG
Output Voltage Load Regulation (Note 4)
Measured in Servo Loop; ΔI
TH
Voltage = 1.2V to 0.7V
Measured in Servo Loop; ΔI
TH
Voltage = 1.2V to 2V
l
l
0.1
–0.1
0.5
–0.5
%
%
g
m
Transconductance Amplifi er g
m
I
TH
= 1.2V; Sink/Source 5μA (Note 4) 1.55 mmho
I
Q
Input DC Supply Current
Sleep Mode
Shutdown
(Note 5)
RUN = 5V, V
FB
= 0.83V (No Load)
V
RUN
= 0V
80
10
125
20
μA
μA
UVLO Undervoltage Lockout V
IN
Ramping Down
l
3.5 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 –660 μA
DF
MAX
Maximum Duty Factor In Dropout 98 99.4 %
I
TRACK/SS
Soft-Start Charge Current V
TRACK
= 0V 0.75 1.0 1.35 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
V
FB
= 0.7V, V
SENSE
–
= 3.3V
l
90
80
100
100
110
115
mV
mV
TG1, 2 t
r
TG1, 2 t
f
TG Transition Time:
Rise Time
Fall Time
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
50
50
90
90
ns
ns
BG1, 2 t
r
BG1, 2 t
f
BG Transition Time:
Rise Time
Fall Time
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
40
40
90
80
ns
ns
TG/BG t
1D
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
C
LOAD
= 3300pF 70 ns
BG/TG t
2D
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time
C
LOAD
= 3300pF 70 ns
t
ON(MIN)
Minimum On-Time (Note 7) 180 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
Sourcing Capability
f
PLLIN/MODE
< f
OSC
f
PLLIN/MODE
> f
OSC
–5
5
μA
μA
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 LTC3835E-1 is guaranteed to meet performance specifi cations
from 0°C to 85°C. Specifi cations over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTC3835I-1 is guaranteed to
meet performance specifi catons over the full –40°C to 85°C operating
temperature range.