LTC3736-1 Datasheet, PDF (3/28 Pages) Linear Technology – Dual 2-Phase, No RSENSE Synchronous Controller with Spread Spectrum

LTC3736-1
ELECTRICAL CHARACTERISTICS _{The ● denotes specifications that apply over the full operating temperature}
range, otherwise specifications are at T_A = 25°C. V_IN = 4.2V unless otherwise specified.
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Output Voltage Load Regulation
V_FB1,2 Input Current
TRACK Input Current
I_TH = 0.9V (Note 5)
I_TH = 1.7V
(Note 5)
TRACK = 0.6V
0.12 0.5
%
–0.12 –0.5
%
10
50
nA
10
50
nA
Overvoltage Protect Threshold
Overvoltage Protect Hysteresis
Measured at V_FB
0.66 0.68
0.7
V
20
mV
Top Gate (TG) Drive 1, 2 Rise Time
Top Gate (TG) Drive 1, 2 Fall Time
Bottom Gate (BG) Drive 1, 2 Rise Time
Bottom Gate (BG) Drive 1, 2 Fall Time
Maximum Current Sense Voltage
(SENSE⁺ – SW)(∆V_SENSE(MAX))
Soft-Start Time
Spread Spectrum Oscillator
C_L = 3000pF
C_L = 3000pF
C_L = 3000pF
C_L = 3000pF
IPRG = Floating (Note 6)
IPRG = 0V
IPRG = V_IN
Time for V_FB1 to Ramp from 0.05V to 0.55V
40
ns
40
ns
50
ns
40
ns
● 110
125
140
mV
● 70
85
100
mV
● 185
204
223
mV
0.667 0.833
1
ms
Oscillator Frequency
Spread Spectrum Frequency Range
Spread Spectrum Disabled (SSDIS = V_IN)
V_FREQ = Floating
V_FREQ = 0V
V_FREQ = V_IN
SSDIS = GND
Minimum Switching Frequency
Maximum Switching Frequency
● 480
550
600
kHz
● 260
300
340
kHz
● 650
750
825
kHz
450
kHz
580
kHz
PGOOD Output
PGOOD Voltage Low
PGOOD Trip Level
I_PGOOD Sinking 1mA
V_FB with Respect to Set Output Voltage
V_FB < 0.6V, Ramping Positive
V_FB < 0.6V, Ramping Negative
V_FB > 0.6V, Ramping Negative
V_FB > 0.6V, Ramping Positive
125
mV
–13 –10.0 –7
%
–16 –13.3 –10
%
7
10.0
13
%
10
13.3
16
%
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC3736E-1 is guaranteed to meet specified performance
from 0°C to 70°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°C/W)
Note 4: Dynamic supply current is higher due to gate charge being
delivered at the switching frequency.
Note 5: The LTC3736-1 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 2.
37361f
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