LTC3731 Datasheet, PDF (3/32 Pages) Linear Technology – 3-Phase, 600kHz, Synchronous Buck Switching Regulator Controller

LTC3731
ELECTRICAL CHARACTERISTICS The ● 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
V_SENSEMAX Maximum Current Sense Threshold
I_MATCH
V_LOADREG
Maximum Current Threshold Match
Output Voltage Load Regulation
V_REFLNREG Output Voltage Line Regulation
g_m
Transconductance Amplifier g_m
g_mOL
Transconductance Amplifier GBW
V_FCB
Forced Continuous Threshold
I_FCB
V_BINHIBIT
UVR
FCB Bias Current
Burst Inhibit Threshold
Undervoltage RUN/SS Reset
UVADJ
Undervoltage Lockout Threshold
I_UVADJ
I_Q
Undervoltage Bias Current
Input DC Supply Current
Normal Mode
Shutdown
I_RUN/SS
V_RUN/SS
V_RUN/SSARM
Soft-Start Charge Current
RUN/SS Pin ON Threshold
RUN/SS Pin Arming Threshold
V_RUN/SSLO
I_SCL
I_SDLHO
I_SENSE
RUN/SS Pin Latch-Off Threshold
RUN/SS Discharge Current
Shutdown Latch Disable Current
SENSE Pins Source Current
DF_MAX
TG t_R,t_F
BG t_R, t_F
TG/BG t_1D
BG/TG t_2D
t_ON(MIN)
Maximum Duty Factor
Top Gate Rise Time
Top Gate Fall Time
Bottom Gate Rise Time
Bottom Gate Fall Time
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time
Minimum On-Time
CONDITIONS
V_EAIN = 0.5V, V_ITH Open,
V_SENSE1–_, V_SENSE2–_, V_SENSE3– = 0.6V, 1.8V
●
LTC3731IG
●
Worst-Case Error at V_SENSEMAX
(Note 3)
Measured in Servo Loop, ∆I_TH Voltage = 1.2V to 0.7V ●
LTC3731IG
●
Measured in Servo Loop, ∆I_TH Voltage = 1.2V to 2V ●
LTC3731IG
●
V_CC = 4.5V to 7V
I_TH = 1.2V, Sink/Source 25µA (Note 3)
●
LTC3731IG
●
I_TH = 1.2V (g_m • Z_L, Z_L = Series 1k-100kΩ-1nF)
●
LTC3731IG
●
V_FCB = 0.65V
Measured at FCB Pin
V_CC Lowered Until the RUN/SS Pin is Pulled Low
At UVADJ Threshold
(Note 4)
V_CC = 5V
V_RUN/SS = 0V
V_RUN/SS = 1.9V
V_RUN/SS, Ramping Positive
V_RUN/SS, Ramping Positive Until Short-Circuit
Latch-Off is Armed
V_RUN/SS, Ramping Negative
Soft-Short Condition V_EAIN = 0.375V, V_RUN/SS = 4.5V
V_EAIN = 0.375V, V_RUN/SS = 4.5V
SENSE1⁺, SENSE1^–, SENSE2⁺, SENSE2^–, SENSE3⁺
SENSE3^– All Equal 1.2V; Current at Each Pin
In Dropout, V_SENSEMAX ≤ 30mV
C_LOAD = 3300pF
C_LOAD = 3300pF
C_LOAD = 3300pF
C_LOAD = 3300pF
All Controllers, C_LOAD = 3300pF Each Driver
All Controllers, C_LOAD = 3300pF Each Driver
Tested with a Square Wave (Note 5)
MIN TYP MAX
65
75
85
62
75
88
60
90
–5
5
0.1
0.5
0.1
0.7
–0.1 –0.5
–0.1 –0.7
0.03
4
5
6
3
5
7
3
0.58 0.60 0.62
0.54 0.60 0.66
0.2
0.7
V_CC – 1.5 V_CC – 0.7 V_CC – 0.3
3.3 3.8
4.5
1.13 1.18 1.23
0.2
50
2.3
3.5
50
100
–0.8 –1.5 – 2.5
1
1.5
1.9
3.8
4.5
3.2
–5 –1.5
1.5
5
13
20
95 98.5
30
90
40
90
30
90
20
90
50
60
110
UNITS
mV
mV
mV
%
%
%
%
%
%/V
mmho
mmho
MHz
V
V
µA
V
V
V
nA
mA
µA
µA
V
V
V
µA
µA
µA
%
ns
ns
ns
ns
ns
ns
ns
3731fa
3