LTC1147-3.3_15 Datasheet, PDF (3/16 Pages) Linear Technology – High Efficiency Step-Down Switching Regulator Controllers

LTC1147-3.3
LTC1147-5/LTC1147L
ELECTRICAL CHARACTERISTICS T_A = 25°C, V_IN = 10V, V_SHDN = 0V, unless otherwise noted.
SYMBOL
V₅ – V₄
PARAMETER
Current Sense Threshold Voltage (Note 6)
LTC1147-3.3, LTC1147L-3.3
LTC1147–5
LTC1147L
V₆
SHDN Pin Threshold
LTC1147-3.3/LTC1147-5/LTC1147L-3.3
I₆
SHDN Pin Input Current
LTC1147-3.3/LTC1147-5/LTC1147L-3.3
I₂
C_T Pin Discharge Current
t_OFF
Off-Time (Note 3)
t_r, t_f
Driver Output Transition Times
CONDITIONS
V_SENSE– = V_OUT + 100mV (Forced)
V_SENSE– = V_OUT – 100mV (Forced)
V_SENSE– = V_OUT + 100mV (Forced)
V_SENSE– = V_OUT – 100mV (Forced)
V_SENSE– = 5V, V6 = V_OUT/4 + 25mV (Forced)
V_SENSE– = 5V, V6 = V_OUT/4 – 25mV (Forced)
0V < V_SHDN < 8V, V_IN = 16V
V_OUT in Regulation, V_SENSE ^– = V_OUT
V_OUT = 0V
C_T = 390pF, I_LOAD = 700mA
C_L = 3000pF (Pin 8), V_IN = 6V
MIN TYP MAX UNITS
25
mV
130
150
170
mV
25
mV
130
150
170
mV
25
mV
130
150
170
mV
0.5
0.8
2
V
1.2
5
µA
50
70
90
µA
2
10
µA
4
5
6
µs
100 200
ns
– 40°C ≤ T_A ≤ 85°C (Note 4), V_IN = 10V, unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX
UNITS
V₆
Feedback Voltage (LTC1147L)
V_IN = 9V
q 1.20 1.25 1.30
V
V_OUT
Regulated Output Voltage
LTC1147-3.3/LTC1147L-3.3
LTC1147-5
V_IN = 9V
I_LOAD = 700mA
I_LOAD = 700mA
q 3.17 3.33 3.43
V
q 4.85 5.05 5.20
V
I_Q
Input DC Supply Current (Note 2)
LTC1147 Series
Normal Mode
Sleep Mode
Sleep Mode (LTC1147-5)
Shutdown
LTC1147L Series
Normal Mode
Sleep Mode
Shutdown (LTC1147L-3.3)
(Note 5)
4V < V_IN < 12V
4V < V_IN < 12V
5V < V_IN < 12V
V_SHDN = 2.1V, 4V < V_IN < 12V
3.5V < V_IN < 12V
3.5V < V_IN < 12V
V_SHDN = 2.1V, 3.5V < V_IN < 12V
1.6 2.4
mA
160 260
µA
160 260
µA
10 22
µA
1.6 2.4
mA
160 260
µA
10 22
µA
V₅ – V₄
Current Sense Threshold Voltage (Note 6)
LTC1147-3.3
V_SENSE ^– = V_OUT + 100mV (Forced)
25
mV
V_SENSE ^– = V_OUT – 100mV (Forced)
q 125
150 185
mV
LTC1147-5
V_SENSE ^– = V_OUT + 100mV (Forced)
25
mV
V_SENSE ^– = V_OUT – 100mV (Forced)
q 125
150 185
mV
LTC1147L
V_SENSE– = 5V, 6V = V_OUT/4 + 25mV (Forced)
25
mV
V_SENSE– = 5V, 6V = V_OUT/4 – 25mV (Forced)
125
150 185
mV
V₆
SHDN Pin Threshold
LTC1147-3.3/LTC1147-5/LTC1147L-3.3 0V < V_SHDN < 8V, V_IN = 16V
0.5
0.8 2
V
t_OFF
Off-Time (Note 3)
C_T = 390pF, I_LOAD = 700mA
3.8
5 6.5
µs
The q denotes specifications which apply over the full specified
temperature range.
Note 1: T_J is calculated from the ambient temperature T_A and power
dissipation P_D according to the following formulas:
LTC1147CN8-3.3/LTC1147CN8-5: T_J = T_A + (P_D)(110°C/W)
LTC1147LIS/LTC1147IS8/LTC1147LCS/
LTC1147CS8-3.3/LTC1147CS8-5: T_J = T_A + (P_D)(150°C/W)
Note 2: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 3: In applications where R_SENSE is placed at ground potential, the off-
time increases approximately 40%.
Note 4: The LTC1147C is guaranteed to meet specified performance from
0°C to 70°C and is designed, characterized and expected to meet these
extended temperature limits, but is not tested at – 40°C and 85°C. The
LTC1147I is guaranteed to meet the extended temperature limits.
Note 5: The LTC1147L/LTC1147L-3.3 allow operation to V_IN = 3.5V.
Note 6: The LTC1147L is tested with external feedback resistors resulting
in a nominal output voltage of 2.5V.
sn1147 1147fds
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