LTC3822-1 Datasheet, PDF (3/24 Pages) Linear Technology – No RSENSE, Low Input Voltage, Synchronous Step-Down DC/DC Controller

LTC3822-1
ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_IN = 3.3V unless otherwise noted.
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Output Voltage Load Regulation
TRACK/SS Pull-Up Current
I_TH = 1.3V to 0.9V (Note 5)
I_TH = 1.3V to 1.7V
TRACK/SS = 0V
0.1
0.5
%
–0.1 –0.5
%
0.65
1
1.35
µA
V_FB Input Current
(Note 5)
10
50
nA
Overvoltage Protect Threshold
Measured at V_FB
0.66 0.68 0.70
V
Overvoltage Protect Hysteresis
20
mV
Top Gate (TG) Drive Rise Time
Top Gate (TG) Drive Fall Time
Bottom Gate (BG) Drive Rise Time
Bottom Gate (BG) Drive Fall Time
C_L = 3000pF
C_L = 3000pF
C_L = 3000pF
C_L = 3000pF
40
ns
40
ns
50
ns
40
ns
Maximum Duty Cycle
In Dropout
99
%
Maximum Current Sense Voltage (V_IN – SW)
(ΔV_SENSE(MAX))
Soft-Start Time
IPRG = Floating
IPRG = 0V
IPRG = V_IN
● 110
125
140
mV
● 70
82
95
mV
● 185
200
220
mV
Time for V_FB to Ramp from 0.05V to 0.55V
650
µs
Oscillator
Oscillator Frequency
PLLLPF = Floating
PLLLPF = 0V
PLLLPF = V_IN
480
550
600
kHz
240
300
340
kHz
640
750
850
kHz
Phase-Locked Loop Lock Range
SYNC/MODE Clocked
Minimum Synchronizable Frequency
Maximum Synchronizable Frequency
200
250
kHz
750 1000
kHz
Phase detector Output Current
Sinking
Sourcing
PGOOD Output (GN Package Only)
f_OSC > f_SYNC/MODE
f_OSC < f_SYNC/MODE
–5
µA
5
µA
PGOOD Voltage Low
PGOOD Trip Level
I_PGOOD Sinking 1mA
V_FB with Respect to Set Output Voltage
V_FB < 0.6V, Ramping Postive
V_FB < 0.6V, Ramping Negative
V_FB > 0.6V, Ramping Negative
V_FB > 0.6V, Ramping Positive
100
mV
–13 –10.0 –7
%
–16 –13.3 –10
%
7
10.0 13
%
10
13.3 16
%
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 LTC3822E-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.
Note 3: T_J is calculated from the ambient temperature T_A and power
dissipation P_D according to the following formula:
T_J = T_A + (P_D • θ_JA)
Note 4: Dynamic supply current is higher due to gate charge being
delivered at the switching frequency.
Note 5: The LTC3822-1 is tested in a feedback loop that servos I_TH to a
specified voltage and measures the resultant V_FB voltage.
38221f
3