LTC3646-1 Datasheet, PDF (3/28 Pages) Linear Technology – 40V, 1A Synchronous Step-Down Converter 1A Guaranteed Output Current

LTC3646/LTC3646-1
Electrical Characteristics The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C (Note 2), PVIN = SVIN = 12V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN
TYP MAX
Input Supply (PVIN, SVIN)
V_IN
V_IN(OV)
Input Voltage Operating  Range
Input Supply Overvoltage Lockout
V_IN(UV)
Input Supply Undervoltage Lockout
I_Q
DC Supply Current (Note 3)
Forced Continuous
Sleep Mode
Shutdown Mode
Main Control Loop
V_IN Rising
Hysteresis (V_IN Falling)
V_IN Falling
Hysteresis (V_IN Rising)
V_RUN = 0V
l
4.0
l
43.5
l
2.0
3.2
40
46
2.5
2.9
3.35
3.5
250
620
875
140
190
8
V_OUT
Output Voltage Range (Note 4)
LTC3646
LTC3646-1
2.0
30
0.6
15
V_FB
Feedback Reference Voltage
–40°C < T_A < 85°C
0.594
l
0.591
0.6 0.606
0.6 0.609
g_m(EA)
t_ON(MIN)
t_OFF(MIN)
I_LIM
Feedback  Voltage Line Regulation
Feedback  Voltage Load Regulation
Feedback Input Current
Error Amplifier Transconductance
Minimum On-Time
Minimum Off-Time
Valley Switch Current Limit
Internal Oscillator Frequency
External Clock Frequency Range
V_IN = 4.0V to 40V, I_TH = 1.5V
I_TH = 1.0V to 1.8V
V_FB = 0.6V
External Comp
V_IN = 40V, R_RT = 30k, V_ON = 2V
V_RT = V_INTVCC
R_RT = 450kΩ
R_RT = 60kΩ
R_RT = 30kΩ
l
l
0.9
1.6
0.19
1.25
2.55
0.2
0.05
0.12
0
±20
300
30
80
1.2
1.5
2.25 2.95
0.2
0.27
1.5
1.75
3.0
3.45
3.0
R_DS(ON)
Top Switch On-Resistance (Note 5)
Bottom Switch On-Resistance (Note 5)
Switch Leakage
Internal V_CC Regulator
V_INTVCC
INTV_CC Voltage
INTV_CC Load Regulation (Note 6)
INTV_CC Undervoltage Lockout
INTV_CC UVLO Hysteresis
EXTV_CC Switchover Voltage
EXTV_CC Hysteresis
Operation
V_IN = 5.5V
V_IN = 5.5V
V_IN = V_SW = 40V, V_RUN = 0
V_IN = 40V, V_SW = 0V, V_RUN = 0
I_INTVCC = 0mA to 5mA
INTV_CC Falling
EXTV_CC Rising
l
4.8
4.25
200
120
±1
±1
5.0
5.2
0.5
3.0
0.3
4.5
4.65
200
V_RUN
RUN Pin Threshold
RUN Rising
RUN Falling
Hysteresis
1.17
1.21 1.26
1.06
1.10 1.14
110
RUN Pin Leakage Current
RUN = 1.3V
0
±1
V_PGOOD(UT) PGOOD Overvoltage Threshold
FB Rising
FB Falling
5.0
7.5
10
3.5
5
V_PGOOD(LT) PGOOD Undervoltage Threshold
FB Falling
FB Rising
–5.0
–7.5
–10
–3.5
–5
t_PGOOD
PGOOD Filter Time
RT = INTV_CC
15
30
UNITS
V
V
V
V
mV
µA
µA
µA
V
V
V
V
%
%
nA
µS
ns
ns
A
MHz
MHz
MHz
MHz
MHz
mΩ
mΩ
µA
µA
V
%
V
V
V
mV
V
V
mV
µA
%V_FB
%V_FB
µs
36461f
3