Datasheet
3
LTC1574
LTC1574-3.3/LTC1574-5
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 9V, SHDN = V
IN
, I
PGM
= 0V, unless otherwise specified.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
IH
SHDN Pin Input Current SHDN = 16V 2 µA
I
IL
SHDN Pin Input Current 0 ≤ SHDN ≤ 0.8V 0.5 µA
V
F
Schottky Diode Forward Voltage Forward Current = 200mA 0.450 0.570 V
I
R
Schottky Reverse Current Reverse Voltage = 5V 10 25 µA
Reverse Voltage = 18.5V 100 250 µA
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formulas:
T
J
= T
A
+ (P
D
• 110°C/W)
Note 3: Guaranteed by design.
Note 4: Does not include Schottky reverse current. Dynamic supply
current is higher due to the gate charge being delivered at the switching
frequency.
Note 5: Current into Pin 5 only, measured without electrolytic input
capacitor.
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
Efficiency vs Input VoltageEfficiency vs Load CurrentEfficiency vs Load Current
Switch Resistance vs
Input Voltage
Switch Leakage Current
vs Temperature
Efficiency Using Different Types
of Inductor Core Material
ELECTRICAL CHARACTERISTICS
LOAD CURRENT (mA)
1
EFFICIENCY (%)
10 100
1574 • TPC01
500
100
90
80
70
60
50
L = 50µH
V
OUT
= 3.3V
I
PGM
= V
IN
COIL = CTX50-4
V
IN
= 5V
V
IN
= 9V
LOAD CURRENT (mA)
1
EFFICIENCY (%)
10 100
1574 • TPC02
400
100
95
90
85
80
75
70
L = 50µH
V
OUT
= 5V
I
PGM
= V
IN
COIL = CTX50-4
V
IN
= 6V
V
IN
= 9V
INPUT VOLTAGE (V)
5
EFFICIENCY (%)
7
9
10 14
1574 • TPC03
68
11
12
13
95
94
93
92
91
90
89
V
OUT
= 5V
L = 100µH
COIL = CTX100-4
I
LOAD
= 300mA
I
PGM
= V
IN
I
LOAD
= 100mA
I
PGM
= 0V
LOAD CURRENT (mA)
1
EFFICIENCY (%)
10 100 500
100
90
80
70
60
50
V
IN
= 5V
V
OUT
= 3.3V
I
PGM
= V
IN
CTX50-4
CTX50-4P
1574 • TPC04
TEMPERATURE (°C)
0
LEAKAGE CURRENT (nA)
180
160
140
120
100
80
60
40
20
0
40
80
100
1574 • TPC05
20 60
V
IN
= 13.5V
INPUT VOLTAGE (V)
4
RDS
(ON)
(Ω)
12
1574 • TPC06
6
8
10
14 16 18 20
T
A
= 25°C
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7