LTC3787
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at TA = 25°C, VBIAS = ±2V, unless otherwise noted (Note 2).
SYMBOL
Main Control Loop
VBIAS Chip Bias Voltage Operating Range
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
4.5
38
1.212
50
V
V
l
V
Regulated Feedback Voltage
Feedback Current
I
TH
= 1.2V (Note 4)
1.188
1.200
5
FB
I
FB
(Note 4)
nA
%/V
%
V
V
Reference Line Voltage Regulation
VBIAS = 6V to 38V
Measured in Servo Loop;
0.002
0.01
0.02
0.1
REFLNREG
LOADREG
l
l
Output Voltage Load Regulation
(Note 4)
ΔI Voltage = 1.2V to 0.7V
TH
Measured in Servo Loop;
–0.01
2
–0.1
%
ΔI Voltage = 1.2V to 2V
TH
g
Error Amplifier Transconductance
I
TH
= 1.2V
mmho
m
I
Q
Input DC Supply Current
Pulse-Skipping or Forced Continuous Mode
Sleep Mode
(Note 5)
RUN = 5V; V = 1.25V (No Load)
1.2
135
8
mA
ꢀA
ꢀA
FB
RUN = 5V; V = 1.25V (No Load)
300
20
FB
Shutdown
RUN = 0V
l
l
UVLO
INTV Undervoltage Lockout Thresholds
V
V
Ramping Up
Ramping Down
4.1
3.8
4.3
V
V
CC
INTVCC
INTVCC
3.6
l
V
V
RUN Pin ON Threshold
RUN Pin Hysteresis
V
Rising
1.18
1.28
100
4.5
0.5
10
1.38
V
mV
ꢀA
RUN
RUN
RUNHYS
RUNHYS
RUN
I
I
I
RUN Pin Hysteresis Current
RUN Pin Current
V
V
V
> 1.28V
RUN
< 1.28V
ꢀA
RUN
Soft-Start Charge Current
Maximum Current Sense Threshold
= GND
7
13
ꢀA
SS
SS
l
l
l
V
V
FB
V
FB
V
FB
= 1.1V, I = INTV
90
68
42
100
75
50
110
82
56
mV
mV
mV
SENSE1,2(MAX)
SENSE(MATCH)
SENSE(CM)
LIM
LIM
LIM
CC
= 1.1V, I = Float
= 1.1V, I = GND
l
l
l
V
Matching Between V
SENSE2(MAX)
and
V
V
V
= 1.1V, I = INTV
–12
–10
–9
0
0
0
12
10
9
mV
mV
mV
SENSE1(MAX)
FB
FB
FB
LIM
LIM
LIM
CC
V
= 1.1V, I = Float
= 1.1V, I = GND
V
I
SENSE Pins Common Mode Range (BOOST
2.5
38
V
Converter Input Supply Voltage V )
IN
+
SENSE Pin Current
V
V
C
C
C
C
= 1.1V, I = Float
200
300
1
ꢀA
ꢀA
ns
ns
ns
ns
Ω
+
–
SENSE1,2
FB
LIM
–
I
t
t
t
t
SENSE Pin Current
= 1.1V, I = Float
LIM
SENSE1,2
r(TG1,2)
f(TG1,2)
r(BG1,2)
r(BG1,2)
FB
Top Gate Rise Time
= 3300pF (Note 6)
= 3300pF (Note 6)
= 3300pF (Note 6)
= 3300pF (Note 6)
20
20
LOAD
LOAD
LOAD
LOAD
Top Gate Fall Time
Bottom Gate Rise Time
20
Bottom Gate Fall Time
20
R
R
R
R
Top Gate Pull-Up Resistance
Top Gate Pull-Down Resistance
Bottom Gate Pull-Up Resistance
Bottom Gate Pull-Down Resistance
1.2
1.2
1.2
1.2
70
UP(TG1,2)
DN(TG1,2)
UP(TG1,2)
DN(TG1,2)
D(TG/BG)
Ω
Ω
Ω
t
t
Top Gate Off to Bottom Gate On Switch-On
Delay Time
C
C
= 3300pF (Each Driver)
= 3300pF (Each Driver)
ns
LOAD
LOAD
Bottom Gate Off to Top Gate On Switch-On
Delay Time
70
ns
D(BG/TG)
DF
Maximum BG Duty Factor
Minimum BG On-Time
96
%
BG1,2(MAX)
t
(Note 7)
110
ns
ON(MIN)
3787fc
3
Linear Systems [ Linear Systems ]
