Linear Technology LTC3729, Manual, Page: 3 / 28

3
LTC3729
sn3729 3729fas
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
ELECTRICAL CHARACTERISTICS
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25
°
C. V
IN
= 15V, V
RUN/SS
= 5V unless otherwise noted.
V
REFLNREG
Reference Voltage Line Regulation V
IN
= 3.6V to 30V (Note 3) 0.002 0.02 %/V
V
OVL
Output Overvoltage Threshold Measured at V
EAIN
● 0.84 0.86 0.88 V
UVLO Undervoltage Lockout V
IN
Ramping Down 3 3.5 4 V
g
m
Transconductance Amplifier g
m
I
TH
= 1.2V; Sink/Source 5
µ
A; (Note 3) 3 mmho
g
mOL
Transconductance Amplifier Gain I
TH
= 1.2V; (g
m
xZ
L
; No Ext Load); (Note 3) 1.5 V/mV
I
Q
Input DC Supply Current (Note 4)
Normal Mode EXTV
CC
Tied to V
OUT
; V
OUT
= 5V 580
µ
A
Shutdown V
RUN/SS
= 0V 20 40
µ
A
I
RUN/SS
Soft-Start Charge Current V
RUN/SS
= 1.9V – 0.5 – 1.2
µ
A
V
RUN/SS
RUN/SS Pin ON Threshold V
RUN/SS
Rising 1.0 1.5 1.9 V
V
RUN/SSLO
RUN/SS Pin Latchoff Arming V
RUN/SS
Rising from 3V 3.8 4.5 V
I
SCL
RUN/SS Discharge Current Soft Short Condition V
EAIN
= 0.5V; V
RUN/SS
= 4.5V 0.5 2 4
µ
A
I
SDLDO
Shutdown Latch Disable Current V
EAIN
= 0.5V 1.6 5
µ
A
I
SENSE
Total Sense Pins Source Current Each Channel; V
SENSE1
–
, 2
– = V
SENSE1
+
, 2
+ = 0V – 85 – 60
µ
A
DF
MAX
Maximum Duty Factor In Dropout 98 99.5 %
Top Gate Transition Time:
TG1, 2 t
r
Rise Time C
LOAD
= 3300pF 30 90 ns
TG1, 2 t
f
Fall Time C
LOAD
= 3300pF 40 90 ns
Bottom Gate Transition Time:
BG1, 2 t
r
Rise Time C
LOAD
= 3300pF 30 90 ns
BG1, 2 t
f
Fall Time C
LOAD
= 3300pF 20 90 ns
TG/BG t
1D
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
C
LOAD
= 3300pF Each Driver 90 ns
BG/TG t
2D
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time
C
LOAD
= 3300pF Each Driver 90 ns
t
ON(MIN)
Minimum On-Time Tested with a Square Wave (Note 5) 100 ns
Internal V
CC
Regulator
V
INTVCC
Internal V
CC
Voltage 6V < V
IN
< 30V; V
EXTVCC
= 4V 4.8 5.0 5.2 V
V
LDO
INT INTV
CC
Load Regulation I
CC
= 0 to 20mA; V
EXTVCC
= 4V 0.2 1.0 %
V
LDO
EXT EXTV
CC
Voltage Drop I
CC
= 20mA; V
EXTVCC
= 5V 80 160 mV
V
EXTVCC
EXTV
CC
Switchover Voltage I
CC
= 20mA, EXTV
CC
Ramping Positive ● 4.5 4.7 V
V
LDOHYS
EXTV
CC
Switchover Hysteresis I
CC
= 20mA, EXTV
CC
Ramping Negative 0.2 V
Oscillator and Phase-Locked Loop
f
NOM
Nominal Frequency V
PLLFLTR
= 1.2V 360 400 440 kHz
f
LOW
Lowest Frequency V
PLLFLTR
= 0V 230 260 290 kHz
f
HIGH
Highest Frequency V
PLLFLTR
≥
2.4V 480 550 590 kHz
R
PLLIN
PLLIN Input Resistance 50 k
Ω
I
PLLFLTR
Phase Detector Output Current
Sinking Capability f
PLLIN
< f
OSC
– 15
µ
A
Sourcing Capability f
PLLIN
> f
OSC
15
µ
A
R
RELPHS
Controller 2-Controller 1 Phase V
PHASMD
= 0V, Open 180 Deg
V
PHASMD
= 5V 240 Deg