LTC1435A Linear Technology, LTC1435A Datasheet - Page 3

• Manufacturer Part Number: LTC1435A
• Description: High Efficiency Low Noise Synchronous Step-Down Switching Regulator
• Manufacturer: Linear Technology

ELECTRICAL CHARACTERISTICS
SYMBOL
Oscillator
f
The
temperature range.
Note 1: T
dissipation P
Note 2: The LTC1435A is tested in a feedback loop which servos V
to the balance point for the error amplifier (V
TYPICAL PERFORMANCE CHARACTERISTICS
OSC
100
0.2
0.1
0.5
0.4
0.3
LTC1435ACG/LTC1435ACS: 0 C T
LTC1435AIG/LTC1435AIS: – 40 C T
LTC1435ACG/LTC1435AIG: T
LTC1435ACS/LTC1435AIS: T
95
90
85
80
75
70
0
0
0
denotes specifications which apply over the full operating
Efficiency vs Input Voltage
V
V
vs Load Current
R
V
OUT
V
IN
SENSE
OUT
J
OUT
is calculated from the ambient temperature T
– V
0.5
DROP OF 5%
= 3.3V
= 3.3V
5
D
OUT
= 0.033
PARAMETER
Oscillator Frequency
according to the following formula:
INPUT VOLTAGE (V)
LOAD CURRENT (A)
1.0
10
Dropout Voltage
I
LOAD
1.5
15
= 1A
I
LOAD
2.0
20
J
J
= 100mA
= T
= T
W
A
A
2.5
25
A
+ (P
+ (P
1435A G01
1435A G04
A
70 C
D
U
D
3.0
85 C
30
)(110 C/W)
)(130 C/W)
ITH
= 1.19V).
– 0.25
– 0.50
– 0.75
–1.00
–1.25
–1.50
100
A
95
75
70
90
85
80
0
and power
CONDITIONS
C
OSC
0
Efficiency vs Input Voltage
V
0
Load Regulation
OUT
= 100pF (Note 4)
0.5
I
= 5V
5
LOAD
T
OSENSE
A
= 25 C, V
= 100mA
INPUT VOLTAGE (V)
LOAD CURRENT (A)
1.0
10
1.5
15
Note 3: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 4: Oscillator frequency is tested by measuring the C
discharge currents and applying the formula:
Note 5: The minimum on-time test condition corresponds to an inductor
peak-to-peak ripple current 40% of I
Considerations in the Applications Information section).
IN
I
LOAD
f
R
= 15V, V
OSC
SENSE
2.0
20
= 1A
(kHz) =
V
= 0.033
OUT
2.5
25
RUN/SS
1435A G02
1435A G05
= 5V
C
3.0
30
OSC
8.4(10
= 5V unless otherwise noted.
(pF) + 11
8
)
100
3.0
2.5
2.0
1.5
1.0
0.5
80
95
90
85
75
70
65
60
55
50
0
0.001
0
Efficiency vs Load Current
V
V
V
R
I
ITH
OPERATION
Burst Mode
CHG
IN
OUT
SENSE
10
1
= 10V
MIN
MAX
112
Pin Voltage vs Output Current
= 5V
Burst Mode
OPERATION
+
20
= 0.033
0.01
I
(see Minimum On-Time
DIS
OUTPUT CURRENT (%)
1
30
LOAD CURRENT (A)
TYP
125
–1
40
CONTINUOUS
MODE
LTC1435A
0.1
50
CONTINUOUS
MODE
MAX
60
138
OSC
70
charge and
1
80
UNITS
1435A G03
1435A G06
90
3
kHz
100
10