LTC3834-1 Datasheet, PDF (3/28 Pages) Linear Technology – 30μA IQ Synchronous Step-Down Controller

LTC3834-1
ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_IN = 12V, V_RUN = 5V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
V_LOADREG Output Voltage Load Regulation
(Note 4)
Measured in Servo Loop; I _TH Voltage = 1.2V to 0.7V ●
Measured in Servo Loop; I _TH Voltage = 1.2V to 2V
●
0.1
0.5
%
– 0.1 – 0.5
%
g_m
Transconductance Amplifier g_m
I_TH = 1.2V; Sink/Source 5μA (Note 4)
0.5
mmho
I_Q
Input DC Supply Current
Sleep Mode
Shutdown
(Note 5)
RUN = 5V, V_FB = 0.83V (No Load)
V_RUN = 0V
30
50
μA
4
10
μA
UVLO
Undervoltage Lockout
V_IN Ramping Down
●
3.7
4
V
V_OVL
Feedback Overvoltage Lockout
Measured at V_FB Relative to Regulated V_FB
8
10
12
%
I_SENSE
Sense Pins Total Source Current V_SENSE– = V_SENSE+ = 0V
–220
μA
DF_MAX
Maximum Duty Factor
In Dropout
98
99.4
%
I_TRACK/SS Soft-Start Charge Current
V_TRACK = 0V
0.85
1.1
1.45
μA
V_RUN ON RUN Pin ON Threshold
V_RUN1, V_RUN2 Rising
0.5
0.7
0.9
V
V_SENSE(MAX) Maximum Current Sense Threshold V_FB = 0.7V, V_SENSE– = 3.3V
● 85
100 115
mV
TG1, 2 t_r
TG1, 2 t_f
TG Transition Time:
Rise Time
Fall Time
(Note 6)
C_LOAD = 3300pF
C_LOAD = 3300pF
50
90
ns
50
90
ns
BG1, 2 t_r
BG1, 2 t_f
BG Transition Time:
Rise Time
Fall Time
(Note 6)
C_LOAD = 3300pF
C_LOAD = 3300pF
40
90
ns
40
80
ns
TG/BG t_1D Top Gate Off to Bottom Gate On Delay C_LOAD = 3300pF
Synchronous Switch-On Delay Time
70
ns
BG/TG t_2D Bottom Gate Off to Top Gate On Delay C_LOAD = 3300pF
Top Switch-On Delay Time
70
ns
t_ON(MIN)
Minimum On-Time
INTV_CC Linear Regulator
V_INTVCCVIN Internal V_CC Voltage
V_LDOVIN
INTV_CC Load Regulation
Oscillator and Phase-Locked Loop
(Note 7)
8.5V < V_IN < 30V
I_CC = 0mA to 20mA
200
ns
5.0
5.25
5.5
V
0.2
1.0
%
f_NOM
f_LOW
f_HIGH
f_SYNCMIN
f_SYNCMAX
I_PLLLPF
Nominal Frequency
V_PLLLPF = No Connect
Lowest Frequency
V_PLLLPF = 0V
Highest Frequency
V_PLLLPF = INTV_CC
Minimum Synchronizable Frequency PLLIN/MODE = External Clock; V_PLLLPF = 0V
Maximum Synchronizable Frequency PLLIN/MODE = External Clock; V_PLLLPF = 2V
Phase Detector Output Current
Sinking Capability
Sourcing Capability
f_PLLIN/MODE < f_OSC
f_PLLIN/MODE > f_OSC
360
400
440
kHz
220 250 280
kHz
475 530 580
kHz
115 140
kHz
650 800
kHz
–5
μA
5
μA
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 LTC3834E-1 is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 85°C operating temperature
range are assured by design, characterization and correlation with statistical
process controls. The LTC3834I-1 is guaranteed to meet performance
specifications over the –40°C to 85°C operating temperature range.
Note 3: T_J is calculated from the ambient temperature T_A and power
dissipation P_D according to the following formulas:
LTC3834GN-1: T_J = T_A + (P_D • 90°C/W)
LTC3834DHC-1: T_J = T_A + (P_D • 43.5°C/W)
Note 4: The LTC3834-1 is tested in a feedback loop that servos V_ITH to a
specified voltage and measures the resultant V_FB.
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).
38341f
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