LTC3417 Datasheet, PDF (3/20 Pages) Linear Technology – Dual Synchronous 1.4A/800mA 4MHz Step-Down DC/DC Regulator

LTC3417
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at T_A = 25°C.
V_IN = 3.6V unless otherwise specified. (Note 2)
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX
I_S
f_OSC
I_LIM1
I_LIM2
R_DS(ON)1
R_DS(ON)2
I_SW1(LKG)
I_SW2(LKG)
V_UVLO
T_PGOOD
Input DC Supply Current (Note 4)
Active Mode
V_FB1 = V_FB2 = 0.75V, V_MODE = V_IN,
V_RUN1 = V_RUN2 = V_IN
Half Active Mode (V_RUN2 = 0V, 1.4A Only) V_FB1 = 0.75V, V_MODE = V_IN, V_RUN1 = V_IN
Half Active Mode (V_RUN1 = 0V, 800mA Only) V_FB2 = 0.75V, V_MODE = V_IN, V_RUN2 = V_IN
Both Channels in Sleep Mode
V_FB1 = V_FB2 = 1V, V_MODE = V_IN,
V_RUN1 = V_RUN2 = V_IN
Shutdown
V_RUN1 = V_RUN2 = 0V
Oscillator Frequency
V_FREQ = V_IN
V_FREQ: R_T = 143k
V_FREQ: Resistor (Note 6)
Peak Switch Current Limit on SW1 (1.4A)
Peak Switch Current Limit on SW2 (800mA)
SW1 Top Switch On-Resistance (1.4A)
SW1 Bottom Switch On-Resistance
SW2 Top Switch On-Resistance (800mA)
SW2 Bottom Switch On-Resistance
Switch Leakage Current SW1 (1.4A)
Switch Leakage Current SW2 (800mA)
Undervoltage Lockout Threshold
Threshold for Power Good. Percentage
Deviation from V_FB Steady State
(Typically 0.8V)
V_IN1 = 3.6V (Note 5)
V_IN1 = 3.6V (Note 5)
V_IN2 = 3.6V (Note 5)
V_IN2 = 3.6V (Note 5)
V_IN1 = 6V, V_ITH1 = 0V, V_RUN1 = 0V
V_IN2 = 6V, V_ITH2 = 0V, V_RUN2 = 0V
V_IN1, V_IN2 Ramping Down
V_IN1, V_IN2 Ramping Up
V_FB1 or V_FB2 Ramping Up, V_MODE = 0V
V_FB1 or V_FB2 Ramping Down, V_MODE = 0V
400 600
260 400
260 400
125 250
0.1
1
1.2
1.5
1.8
0.85
1
1.25
4
1.8 2.25
1
1.2
0.088
0.084
0.16
0.15
0.01
1
0.01
1
1.9
2.07
2.2
1.95 2.12 2.25
–6
–6
R_PGOOD
V_RUN1, V_RUN2
V_PHASE
Power Good Pull-Down On-Resistance
RUN1, RUN2 Threshold
PHASE Threshold High-CMOS Levels
PHASE Threshold Low-CMOS Levels
160 300
0.3
0.85
1.5
V_IN –0.5
0.5
I_RUN1, I_RUN2,
I_PHASE, I_MODE
VTL_MODE
VTH_MODE
VTH_FREQ
RUN1, RUN2, PHASE and MODE
Leakage Current
MODE Threshold Voltage Low
MODE Threshold Voltage High
FREQ Threshold Voltage High
V_IN = 6V, PV_IN = 3V
0.01
1
0.5
V_IN –0.5
V_IN –0.5
UNITS
µA
µA
µA
µA
µA
MHz
MHz
MHz
A
A
Ω
Ω
Ω
Ω
µA
µA
V
V
%
%
Ω
V
V
V
µA
V
V
V
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LTC3417 is guaranteed to meet specified performance from
0°C to 85°C. Specifications over the –40°C to 85°C operating ambient
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: The LTC3417 is tested in feedback loop which servos V_FB1 to the
midpoint for the error amplifier (V_ITH1 = 0.6V) and V_FB2 to the midpoint for
the error amplifier (V_ITH2 = 0.6V).
Note 4: Total supply current is higher due to the internal gate charge being
delivered at the switching frequency.
Note 5: Switch on-resistance is guaranteed by design and test correlation
on the DHC package and by final test correlation on the FE package.
Note 6: Variable frequency operation with resistor is guaranteed by design
but not production tested and is subject to duty cycle limitations.
Note 7: This IC includes overtemperature protection that is intended to
protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 8: T_J is calculated from the ambient temperature, T_A, and power
dissipation, P_D, according to the following formula:
LTC3417EDHC: T_J = T_A + (P_D • 43°C/W)
LTC3417EFE: T_J = T_A + (P_D • 38°C/W)
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