LTC3731_15 Datasheet, PDF (3/34 Pages) Linear Technology – 3-Phase, 600kHz, Synchronous Buck Switching Regulator Controller

ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION
LTC3731CG#PBF
LTC3731CG#TRPBF
LTC3731CG
36-Lead Plastic SSOP
LTC3731IG#PBF
LTC3731IG#TRPBF
LTC3731IG
36-Lead Plastic SSOP
LTC3731CUH#PBF
LTC3731CUH#TRPBF
3731
32-Lead (5mm × 5mm) Plastic QFN
LTC3731IUH#PBF
LTC3731IUH#TRPBF
3731I
32-Lead (5mm × 5mm) Plastic QFN
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
LTC3731
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°C
0°C to 70°C
–40°C to 85°C
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_CC = V_RUN/SS = 5V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
Main Control Loop
V_REGULATED Regulated Voltage at IN⁺
V_ITH = 1.2V (Note 3)
LTC3731I
0.596 0.600 0.604
V
l 0.594 0.600 0.606
V
l 0.591
0.609
V
V_SENSEMAX Maximum Current Sense Threshold
VV_ESAEINNSE=₁0_–,.5VVS,_EV_NISTEH2O_–,pVeSn_E,_{NSE3– = 0.6V, 1.8V}
LTC3731I
65
75
85
mV
l 62
75
88
mV
l 60
90
mV
I_MATCH
Maximum Current Threshold Match Worst-Case Error at V_SENSEMAX
–5
5
%
V_LOADREG Output Voltage Load Regulation
(Note 3)
Measured in Servo Loop, ∆I_TH Voltage = 1.2V to 0.7V l
LTC3731I
l
Measured in Servo Loop, ∆I_TH Voltage = 1.2V to 2V l
LTC3731I
l
0.1
0.5
%
0.1
0.7
%
–0.1
–0.5
%
–0.1
–0.7
%
V_REFLNREG Output Voltage Line Regulation
g_m
Transconductance Amplifier g_m
V_CC = 4.5V to 7V
I_TH = 1.2V, Sink/Source 25µA (Note 3)
LTC3731I
0.03
%/V
l4
5
6
mmho
l3
5
7
mmho
g_mOL
Transconductance Amplifier GBW I_TH = 1.2V (g_m • Z_L, Z_L = Series 1k-100kΩ-1nF)
3
MHz
V_FCB
Forced Continuous Threshold
LTC3731I
l 0.58
0.60
0.62
V
l 0.54
0.60
0.66
V
I_FCB
V_BINHIBIT
FCB Bias Current
Burst Inhibit Threshold
V_FCB = 0.65V
Measured at FCB Pin
0.2
0.7
µA
V_CC – 1.5 V_CC – 0.7 V_CC – 0.3
V
UVR
Undervoltage RUN/SS Reset
V_CC Lowered Until the RUN/SS Pin is Pulled Low
3.3
3.8
4.5
V
UVADJ
Undervoltage Lockout Threshold
1.13
1.18
1.23
V
I_UVADJ
I_Q
Undervoltage Bias Current
Input DC Supply Current
Normal Mode
Shutdown
At UVADJ Threshold
(Note 4)
V_CC = 5V
V_RUN/SS = 0V
0.2
50
nA
2.3
3.5
mA
50
100
µA
I_RUN/SS
Soft-Start Charge Current
V_RUN/SS = 1.9V
–0.8
–1.5
–2.5
µA
3731fc
3