3728L1 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'3728L1' PDF : 32 Pages View PDF
LTC3728L-1
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 15V, VRUN/SS1, 2 = 5V unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Main Control Loops
VOSENSE1, 2
IVOSENSE1, 2
VREFLNREG
VLOADREG
Regulated Feedback Voltage
Feedback Current
Reference Voltage Line Regulation
Output Voltage Load Regulation
gm1, 2
gmGBW1, 2
IQ
VFCB
IFCB
VBINHIBIT
Transconductance Amplifier gm
Transconductance Amplifier GBW
Input DC Supply Current
Normal Mode
Shutdown
Forced Continuous Threshold
Forced Continuous Pin Current
Burst Inhibit (Constant Frequency)
Threshold
(Note 3); ITH1, 2 Voltage = 1.2V
(Note 3)
VIN = 3.6V to 30V (Note 3)
(Note 3)
Measured in Servo Loop; ΔITH Voltage = 1.2V to 0.7V
Measured in Servo Loop; ΔITH Voltage = 1.2V to 2.0V
ITH1, 2 = 1.2V; Sink/Source 5μA; (Note 3)
ITH1, 2 = 1.2V; (Note 3)
(Note 4)
VIN = 15V; EXTVCC Tied to VOUT1; VOUT1 = 5V
VRUN/SS1, 2 = 0V
VFCB = 0.85V
Measured at FCB pin
● 0.788 0.800
–5
0.002
●
0.1
●
– 0.1
1.3
3
450
20
● 0.76 0.800
– 0.50 –0.18
4.3
0.812
–50
0.02
0.5
–0.5
35
0.84
–0.1
4.8
V
nA
%/V
%
%
mmho
MHz
μA
μA
V
μA
V
UVLO
Undervoltage Lockout
VIN Ramping Down
●
3.5
4
V
VOVL
Feedback Overvoltage Lockout
Measured at VOSENSE1, 2
● 0.84 0.86 0.88
V
ISENSE
Sense Pins Total Source Current
(Each Channel); VSENSE1–, 2– = VSENSE1+, 2+ = 0V
–90 –60
μA
DFMAX
Maximum Duty Factor
In Dropout
98 99.4
%
IRUN/SS1, 2
Soft-Start Charge Current
VRUN/SS1, 2 = 1.9V
0.5 1.2
μA
VRUN/SS1, 2 ON RUN/SS Pin ON Threshold
VRUN/SS1, VRUN/SS2 Rising
1.0 1.5 2.0
V
VSENSE(MAX)
Maximum Current Sense Threshold
VOSENSE1, 2 = 0.7V,VSENSE1–, 2– = 5V
VOSENSE1, 2 = 0.7V,VSENSE1–, 2– = 5V
65 75 85
mV
● 62 75 88
mV
TG1, 2 tr
TG1, 2 tf
TG Transition Time:
Rise Time
Fall Time
(Note 5)
CLOAD = 3300pF
CLOAD = 3300pF
55 100
ns
55 100
ns
BG1, 2 tr
BG1, 2 tf
BG Transition Time:
Rise Time
Fall Time
(Note 5)
CLOAD = 3300pF
CLOAD = 3300pF
45 100
ns
45 90
ns
TG/BG t1D
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time CLOAD = 3300pF Each Driver
80
ns
BG/TG t2D
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time
CLOAD = 3300pF Each Driver
80
ns
tON(MIN)
Minimum On-Time
Tested with a Square Wave (Note 6)
100
ns
INTVCC Linear Regulator
VINTVCC
Internal VCC Voltage
6V < VIN < 30V, VEXTVCC = 4V
4.8 5.0 5.2
V
VLDO INT
INTVCC Load Regulation
ICC = 0 to 20mA, VEXTVCC = 4V
0.2 2.0
%
VLDO EXT
EXTVCC Voltage Drop
ICC = 20mA, VEXTVCC = 5V
100 200
mV
VEXTVCC
EXTVCC Switchover Voltage
ICC = 20mA, EXTVCC Ramping Positive
● 4.5 4.7
V
VLDOHYS
EXTVCC Hysteresis
0.2
V
Oscillator and Phase-Locked Loop
fNOM
fLOW
fHIGH
RPLLIN
Nominal Frequency
Lowest Frequency
Highest Frequency
PLLIN Input Resistance
VPLLFLTR = 1.2V
VPLLFLTR = 0V
VPLLFLTR ≥ 2.4V
360 400 440
kHz
230 260 290
kHz
480 550 590
kHz
50
kΩ
3728l1fc
3
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