Datasheet

LTC3735
3
3735fa
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
PVCC
= 5V, V
RUN/SS
= 5V unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loop
Reference Regulated Feedback Voltage I
TH
Voltage = 0.5V; Measured at V
FB
(Note 4) 0.600 V
V
SENSEMAX
Maximum Current Sense Threshold I
TH
Voltage = Max; V
CM
= 1.7V
l
59 72 85 mV
V
LOADREG
Output Voltage Load Regulation (Note 4)
Measured in Servo Loop, ∆I
TH
Voltage: 1.2V to 0.7V
Measured in Servo Loop, ∆I
TH
Voltage: 1.2V to 2V
l
l
0.1
–0.1
0.5
–0.5
%
%
V
REFLNREG
Reference Voltage Line Regulation V
PVCC
= 4.5V to 7V 0.02 0.1 %/V
V
PSIB
Forced Continuous Threshold 0.57 0.6 0.63 V
I
PSIB
Forced Continuous Current V
PSIB
= 0V –0.5 –1 µA
V
OVL
Output Overvoltage Threshold Measured with Respect to V
FB
= 0.6V 0.64 0.66 0.68 V
g
m
Transconductance Amplifier g
m
I
TH
= 1.2V, Sink/Source 25µA (Note 4)
l
4.5 6 7.5 mmho
g
mOL
Transconductance Amplifier Gain I
TH
= 1.2V, (g
m
• Z
L
; No Ext Load) (Note 4) 3 V/mV
V
ACTIVE
Output Voltage in Active Mode VID = 010110, I
TH
= 0.5V (0°C to 85°C)
VID = 010110, I
TH
= 0.5V (Note 2)
l
1.342
1.336
1.356
1.356
1.370
1.376
V
V
I
Q
Input DC Supply Current
Normal Mode
Shutdown
(Note 5)
V
RUN/SS
= 0V
2
20
3
100
mA
µA
UVR Undervoltage RUN/SS Reset PV
CC
Lowered Until the RUN/SS Pin is Pulled Low 3.2 3.7 4.2 V
I
RUN/SS
Soft-Start Charge Current V
RUN/SS
= 1.9V –2.3 –1.5 –0.8 µA
VRUN/SS RUN/SS Pin ON Threshold V
RUN/SS
Rising 1.0 1.5 1.9 V
V
RUN/SSARM
RUN/SS Pin Latchoff Arming V
RUN/SS
Rising from 3V 3.9 V
V
RUN/SSLO
RUN/SS Pin Latchoff Threshold V
RUN/SS
, Ramping Negative 3.2 V
I
SCL
RUN/SS Discharge Current Soft-Short Condition V
FB
= 0.375V, V
RUN/SS
= 4.5V –5 –1.5 µA
I
SDLHO
Shutdown Latch Disable Current V
FB
= 0.375V, V
RUN/SS
= 4.5V 1.5 5 µA
I
SENSE
Total Sense Pins Source Current Each Channel: V
SENSE1
–
, 2
–
= V
SENSE1
+
, 2
+
= 0V –85 –60 µA
DF
MAX
Maximum Duty Factor In Dropout, V
SENSEMAX
≤ 45mV 95 98.5 %
TG1, 2 t
r
TG1, 2 t
f
Top Gate Transition Time:
Rise Time
Fall Time
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
30
40
90
90
ns
ns
BG1, 2 t
r
BG1, 2 t
f
Bottom Gate Transition Time:
Rise Time
Fall Time
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
60
50
90
90
ns
ns
TG/BG t
1D
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
C
LOAD
= 3300pF Each Driver (Note 6) 50 ns
BG/TG t
2D
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time
C
LOAD
= 3300pF Each Driver (Note 6) 60 ns
t
ON(MIN)
Minimum On-Time Tested with a Square Wave (Note 7) 100 ns
VID Parameters
R
ATTEN
VID Top Resistance 5.33 kΩ
ATTEN
ERR
Resistive Divider Error (Note 8)
l
–0.25 0.25 %
VID
THLOW
VID0 to VID5 Logic Threshold Low 0.3 V
VID
THHIGH
VID0 to VID5 Logic Threshold High 0.7 V
VID
LEAK
VID0 to VID5 Leakage ±1 µA