LTC3407-2_15 Datasheet, PDF (3/16 Pages) Linear Technology – Dual Synchronous, 800mA, 2.25MHz Step-Down DC/DC Regulator

LTC3407-2
ELECTRICAL CHARACTERISTICS The ● 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
V_FB
Feedback Voltage (Note 3)
ΔV_{LINE REG}
ΔV_{LOAD REG}
I_S
f_OSC
f_SYNC
I_LIM
R_DS(ON)
Reference Voltage Line Regulation
Output Voltage Load Regulation
Input DC Supply Current
Active Mode
Sleep Mode
Shutdown
Oscillator Frequency
Synchronization Frequency
Peak Switch Current Limit
Top Switch On-Resistance
Bottom Switch On-Resistance
0°C ≤ T_A ≤ 85°C
–40°C ≤ T_A ≤ 85°C
–40°C ≤ T_A ≤ 125°C (Note 2)
V_IN = 2.5V to 5.5V (Note 3)
(Note 3)
0.588
0.6 0.612
V
● 0.585
0.6 0.612
V
● 0.585
0.6 0.612
V
0.3
0.5
%/V
0.5
%
(Note 4)
V_FB1 = V_FB2 = 0.5V
V_FB1 = V_FB2 = 0.63V, MODE/SYNC = 3.6V
RUN = 0V, V_IN = 5.5V, MODE/SYNC = 0V
700
950
μA
40
60
μA
0.1
1
μA
V_FBX = 0.6V
● 1.8
2.25 2.7
MHz
2.25
MHz
V_IN = 3V, V_FBX = 0.5V, Duty Cycle <35%
(Note 6)
(Note 6)
0.95
1.2
1.6
A
0.35 0.45
Ω
0.30 0.45
Ω
I_SW(LKG)
POR
Switch Leakage Current
Power-On Reset Threshold
Power-On Reset On-Resistance
V_IN = 5V, V_RUN = 0V, V_FBX = 0V
V_FBX Ramping Up, MODE/SYNC = 0V
V_FBX Ramping Down, MODE/SYNC = 0V
0.01
1
μA
8.5
%
–8.5
%
100
200
Ω
Power-On Reset Delay
262,144
Cycles
V_RUN
I_RUN
V_MODE
RUN Threshold
RUN Leakage Current
Mode Threshold Low
● 0.3
1
1.5
V
●
0.01
1
μA
0
0.5
V
Mode Threshold High
V_IN – 0.5
V_IN
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 LTC3407E-2 is guaranteed to meet specified performance
from 0°C to 70°C. Specifications over the – 40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTC3407I-2 is guaranteed over the
full –40°C to 125°C operating temperature range.
Note 3: The LTC3407-2 is tested in a proprietary test mode that connects
V_FB to the output of the error amplifier.
Note 4: Dynamic supply current is higher due to the internal gate charge
being delivered at the switching frequency.
Note 5: T_J is calculated from the ambient T_A and power dissipation P_D
according to the following formula: T_J = T_A + (P_D • θ_JA).
Note 6: The DFN switch on-resistance is guaranteed by correlation to
wafer level measurements.
TYPICAL PERFORMANCE CHARACTERISTICS T_A = 25°C unless otherwise specified.
Burst Mode Operation
Pulse-Skipping Mode
Load Step
SW
5V/DIV
V_OUT
100mV/DIV
I_L
200mA/DIV
V_IN = 3.6V
2μs/DIV
V_OUT = 1.8V
I_LOAD = 100mA
CIRCUIT OF FIGURE 1
SW
5V/DIV
V_OUT
10mV/DIV
I_L
200mA/DIV
34072 G01
V_IN = 3.6V
1μs/DIV
V_OUT = 1.8V
I_LOAD = 20mA
CIRCUIT OF FIGURE 1
V_OUT
200mV/DIV
I_L
500mA/DIV
I_LOAD
500mA/DIV
34072 G02
V_IN = 3.6V
20μs/DIV
V_OUT = 1.8V
I_LOAD = 80mA TO 800mA
CIRCUIT OF FIGURE 1
3407 G03
34072fc
3