LTC3426 データシートの表示（PDF） - Linear Technology

部品番号

コンポーネント説明

一致するリスト

LTC3426

1.2MHz Step-Up DC/DC Converter in SOT-23

Linear Technology 

LTC3426

PI FU CTIO S

SW (Pin 1): Switch Pin. Connect inductor between SW and

VIN. A Schottky diode is connected between SW and VOUT.

Keep these PCB trace lengths as short and wide as

possible to reduce EMI and voltage overshoot. If the

inductor current falls to zero, an internal 100Ω antiringing

switch is connected from SW to VIN to minimize EMI.

GND (Pin 2): Signal and Power Ground. Provide a short

direct PCB path between GND and the (–) side of the output

capacitor(s).

FB (Pin 3): Feedback Input to the gm Error Amplifier.

Connect resistor divider tap to this pin. The output voltage

can be adjusted from 2.5V to 5V by:

SHDN (Pin 4): Logic Controlled Shutdown Input.

SHDN = High: Normal free running operation

SHDN = Low: Shutdown, quiescent current < 1µA

Typically, SHDN should be connected to VIN through a 1M

pull-up resistor.

VOUT (Pin 5): Output Voltage Sense Input. The NMOS

switch gate drive is derived from the greater of VOUT and

VIN.

VIN (Pin 6): Input Supply. Must be locally bypassed.

VOUT = 1.22 • ⎛⎝⎜1+ RR21⎞⎠⎟

BLOCK DIAGRA

1.22V

REFERENCE

+

A1

–

3

FB

VOUT

R1 (EXTERNAL)

FB

R2 (EXTERNAL)

VOUT

VIN

COMPARATOR

5

6

–

RC

A2

CC

+

PWM LOGIC

AND DRIVER

Σ

RAMP

GENERATOR

SHDN

4

SHUTDOWN AND

SOFT-START

1.2MHz

OSCILLATOR

Figure 1

SW

1

0.02Ω

2

3426 F01

GND

3426fa

4

Share Link: