LTC1876 Datasheet, PDF (4/36 Pages) Linear Technology – High Efficiency, 2-Phase, Dual Synchronous Step-Down Switching Controller and Step-Up Regulator

LTC1876
ELECTRICAL CHARACTERISTICS The q denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_IN = 15V, V_{RUN/SS1, 2} = 5V, AUXV_IN = 3V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
3.3V Linear Regulator
V_3.3OUT
3.3V Regulator Output Voltage
V_3.3IL
3.3V Regulator Load Regulation
V_3.3VL
3.3V Regulator Line Regulation
PGOOD Output
No Load
I_3.3 = 0mA to 10mA
6V < V_IN < 30V
q 3.25 3.35 3.45
V
0.5
2
%
0.05 0.2
%
V_PGL
I_PGOOD
V_PG
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level, Either Controller
Aux Output
I_PGOOD = 2mA
V_PGOOD = 5V
V_OSENSE with Respect to Set Output Voltage
V_OSENSE Ramping Negative
V_OSENSE Ramping Positive
0.1
0.3
V
±1
µA
–6
–7.5 –9.5
%
6
7.5
9.5
%
AUXV_INMIN
AUXV_FB
AUXI_FB
AUXI_Q
AUXV_LINEREG
AUXf_OSC
AUXDC_MAX
AUXI_LIMIT
AUXV_CESAT
AUXI_LEAKAGE
AUXV_AUXSD
AUX Minimum Operating Voltage
AUX Regulated Feedback Voltage
AUX Feedback Pin Bias Current
AUX Input DC Supply Current
Normal Mode
Shutdown
AUX Line Regulation
AUX Oscillator Frequency
AUX Oscillator Maximum Duty Cycle
AUX Switch Current Limit
AUX Switch Saturation Voltage
AUX Switch Leakage Current
AUX Shutdown Input Voltage
AUX Shutdown Upper Trip Point
AUX Shutdown Lower Trip Point
V_AUXSD = 2.4V, Not Switching
V_AUXSD = 0V
2.6V ≤ AUXV_IN ≤ 16V
(Note 9)
I_SW = 900mA (Note 10)
V_SW = 5V
q
2.4
2.6
V
q 1.23 1.26 1.28
V
q
120
360
nA
4
mA
0.01
1
µA
0.01 0.05
%/V
q 0.8
1.2
1.6
MHz
q 84
86
%
1
1.4
2
A
330
550
mV
0.01
1
µA
2.4
V
0.5
V
I_AUXSD
AUXSD Pin Bias Current
V_AUXSD = 3V
V_AUXSD = 0V
16
32
µA
0.01 0.1
µA
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC1876E is guaranteed to meet performance specifications
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.
Note 3: T_J is calculated from the ambient temperature T_A and power
dissipation P_D according to the following formulas:
LTC1876EG: T_J = T_A + (P_D • 95°C/W)
Note 4: The LTC1876 is tested in a feedback loop that servos V_{ITH1, 2} to a
specified voltage and measures the resultant V_{OSENSE1, 2.}
Note 5: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 6: Rise and fall times are measured using 10% and 90% levels.
Delay times are measured using 50% levels.
Note 7: The minimum on-time condition is specified for an inductor peak-
to-peak ripple current ≥40% of I_MAX (see Minimum On-Time
Considerations in the Applications Information section).
Note 8: V_FREQSET pin internally tied to 1.19V reference through a large
resistance.
Note 9: Current limit guaranteed by design and/or correlation to static test.
Note 10: 100% tested at wafer level.
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