LTC3809-1_15 Datasheet, PDF (3/24 Pages) Linear Technology – No RSENSE, Low Input Voltage, Synchronous DC/DC Controller with Output Tracking

LTC3809-1
ELECTRICAL CHARACTERISTICS The l indicates specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_IN = 4.2V unless otherwise noted.
PARAMETER
CONDITIONS
MIN TYP MAX
Main Control Loops
Input DC Supply Current
Normal Operation
Sleep Mode
Shutdown
UVLO
Undervoltage Lockout Threshold (UVLO)
Shutdown Threshold of RUN Pin
(Note 4)
RUN = 0V
V_IN = UVLO Threshold –200mV
V_IN Falling
V_IN Rising
350
500
105
150
9
20
9
20
l 1.95 2.25 2.55
l 2.15 2.45 2.75
0.8
1.1
1.4
Start-Up Current Source
TRACK/SS = 0V
0.65
1
1.35
Regulated Feedback Voltage
(Note 5)
l 0.591 0.6 0.609
Output Voltage Line Regulation
Output Voltage Load Regulation
V_FB Input Current
Overvoltage Protect Threshold
Overvoltage Protect Hysteresis
2.75V < V_IN < 9.8V (Note 5)
I_TH = 0.9V (Note 5)
I_TH = 1.7V
(Note 5)
Measured at V_FB
0.01 0.04
0.1
0.5
–0.1 –0.5
9
50
0.66 0.68
0.7
20
Auxiliary Feedback Threshold
0.325 0.4 0.475
Top Gate (TG) Drive Rise Time
C_L = 3000pF
40
Top Gate (TG) Drive Fall Time
C_L = 3000pF
40
Bottom Gate (BG) Drive Rise Time
C_L = 3000pF
50
Bottom Gate (BG) Drive Fall Time
C_L = 3000pF
40
Maximum Current Sense Voltage (ΔV_SENSE(MAX))
(V_IN – SW)
Soft-Start Time (Internal)
IPRG = Floating (Note 6)
IPRG = 0V (Note 6)
IPRG = V_IN (Note 6)
Time for V_FB to Ramp from 0.05V to 0.55V
l 110
125
140
l 70
85
100
l 185
204
223
0.5
0.74
0.9
Oscillator Frequency
480
550
600
UNITS
μA
μA
μA
μA
V
V
V
μA
V
%/V
%
%
nA
V
mV
V
ns
ns
ns
ns
mV
mV
mV
ms
kHz
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 LTC3809E-1 is guaranteed to meet specified performance
from 0°C to 85°C. Specifications over the –40°C to 85°C operating range
are assured by design characterization, and correlation with statistical
process controls. The LTC3809I-1 is guaranteed to meet specified
performance over the full –40°C to 85°C operating temperature range.
Note 3: T_J is calculated from the ambient temperature TA and power
dissipation P_D according to the following formula:
T_J = T_A + (P_D • θ_JA °C/W)
Note 4: Dynamic supply current is higher due to gate charge being
delivered at the switching frequency.
Note 5: The LTC3809-1 is tested in a feedback loop that servos I_TH to
a specified voltage and measures the resultant V_FB voltage.
Note 6: Peak current sense voltage is reduced dependent on duty cycle
to a percentage of value as shown in Figure 1.
38091fc
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