LTC3417_15 Datasheet, PDF (3/20 Pages) Linear Technology – Dual Synchronous 1.4A/800mA 4MHz Step-Down DC/DC Regulator

LTC3417
ELECTRICAL CHARACTERISTICS The l denotes the 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 UNITS
g_m(EA)
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
Error Amplifier Transconductance
Input DC Supply Current (Note 4)
Active Mode
Half Active Mode (V_RUN2 = 0V, 1.4A Only)
Half Active Mode (V_RUN1 = 0V, 800mA Only)
Both Channels in Sleep Mode
Shutdown
Oscillator Frequency
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)
I_TH1, I_TH2(PINLOAD) = ±5μA (Note 3)
V_FB1 = V_FB2 = 0.75V, V_MODE = V_IN,
V_RUN1 = V_RUN2 = V_IN
V_FB1 = 0.75V, V_MODE = V_IN, V_RUN1 = V_IN
V_FB2 = 0.75V, V_MODE = V_IN, V_RUN2 = V_IN
V_FB1 = V_FB2 = 1V, V_MODE = V_IN,
V_RUN1 = V_RUN2 = V_IN
V_RUN1 = V_RUN2 = 0V
V_FREQ = V_IN
V_FREQ: R_T = 143k
V_FREQ: Resistor (Note 6)
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_FB1 or V_FB2 Ramping Down
1400
μS
400 600
μA
260 400
μA
260 400
μA
125 250
μA
0.1
1
μA
1.2
1.5
1.8
MHz
0.85
1
1.25
MHz
4
MHz
1.8 2.25
A
1
1.2
A
0.088
Ω
0.084
Ω
0.16
Ω
0.15
Ω
0.01
1
μA
0.01
1
μA
1.9 2.07 2.2
V
1.95 2.12 2.25
V
–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
Ω
0.3 0.85 1.5
V
V_IN –0.5
V
0.5
V
I_RUN1, I_RUN2, RUN1, RUN2, PHASE and MODE
I_PHASE, I_MODE Leakage Current
VTL_MODE
MODE Threshold Voltage Low
VTH_MODE MODE Threshold Voltage High
VTH_FREQ
FREQ Threshold Voltage High
V_IN = 6V, V_PIN = 3V
0.01
1
μA
V_IN –0.5
V_IN –0.5
0.5
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 dis-
sipation, 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)
3417fd
3