LTC1435A Просмотр технического описания (PDF) - Linear Technology

Номер в каталоге

Компоненты Описание

производитель

LTC1435A

High Efficiency Low Noise Synchronous Step-Down Switching Regulator

Linear Technology 

LTC1435A

ELECTRICAL CHARACTERISTICS TA = 25°C, VIN = 15V, VRUN/SS = 5V unless otherwise noted.

SYMBOL

Oscillator

fOSC

PARAMETER

Oscillator Frequency

CONDITIONS

COSC = 100pF (Note 4)

MIN TYP MAX

112 125 138

UNITS

kHz

The q denotes specifications which apply over the full operating

temperature range.

LTC1435ACG/LTC1435ACS: 0°C ≤ TA ≤ 70°C

LTC1435AIG/LTC1435AIS: – 40°C ≤ TA ≤ 85°C

Note 1: TJ is calculated from the ambient temperature TA and power

dissipation PD according to the following formula:

LTC1435ACG/LTC1435AIG: TJ = TA + (PD)(130°C/W)

LTC1435ACS/LTC1435AIS: TJ = TA + (PD)(110°C/W)

Note 2: The LTC1435A is tested in a feedback loop which servos VOSENSE

to the balance point for the error amplifier (VITH = 1.19V).

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 COSC charge and

discharge currents and applying the formula:

( ) ( ) fOSC (kHz) =

8.4(108)

COSC (pF) + 11

1

ICHG

+

1

IDIS

–1

Note 5: The minimum on-time test condition corresponds to an inductor

peak-to-peak ripple current ≥ 40% of IMAX (see Minimum On-Time

Considerations in the Applications Information section).

TYPICAL PERFORMANCE CHARACTERISTICS

Efficiency vs Input Voltage

VOUT = 3.3V

100

VOUT = 3.3V

95

ILOAD = 1A

90

85

ILOAD = 100mA

80

75

70

0

5 10 15 20 25 30

INPUT VOLTAGE (V)

1435A G01

VIN – VOUT Dropout Voltage

vs Load Current

0.5

RSENSE = 0.033Ω

VOUT DROP OF 5%

0.4

0.3

0.2

0.1

0

0 0.5 1.0 1.5 2.0 2.5 3.0

LOAD CURRENT (A)

1435A G04

Efficiency vs Input Voltage

VOUT = 5V

100

VOUT = 5V

95

ILOAD = 1A

90

ILOAD = 100mA

85

80

75

70

0

5 10 15 20 25 30

INPUT VOLTAGE (V)

1435A G02

Load Regulation

0

– 0.25

RSENSE = 0.033Ω

– 0.50

– 0.75

–1.00

–1.25

–1.50

0

0.5 1.0 1.5 2.0 2.5 3.0

LOAD CURRENT (A)

1435A G05

Efficiency vs Load Current

100

VIN = 10V

95 VOUT = 5V

90 RSENSE = 0.033Ω

85

80

75

CONTINUOUS

MODE

70

Burst Mode

OPERATION

65

60

55

50

0.001

0.01

0.1

1

10

LOAD CURRENT (A)

1435A G03

VITH Pin Voltage vs Output Current

3.0

2.5

2.0

1.5

Burst Mode

OPERATION

1.0

0.5

CONTINUOUS

MODE

0

0 10 20 30 40 50 60 70 80 90 100

OUTPUT CURRENT (%)

1435A G06

3

Share Link: