LT1611 Просмотр технического описания (PDF) - Linear Technology

Номер в каталоге

Компоненты Описание

Список матч

LT1611

Inverting 1.4MHz Switching Regulator in SOT-23

Linear Technology 

LT1611

U

OPERATIO

VCESAT

–(VIN + VOUT)

L1

C2

SW

SWX

L2

VIN

+

Q1

D1

C1

C3

–VOUT

RLOAD

1611 F05

Figure 5. Switch-On Phase of Inverting Converter. L1 and L2 Current Have Positive dI/dt

VIN + VOUT+ VD

VD

L1

C2

SW

SWX

L2

VIN

+

Q1

D1

C1

C3

–VOUT

RLOAD

1611 F06

Figure 6. Switch-Off Phase of Inverting Converter. L1 and L2 Current Have Negative dI/dt

Transient Response

The inverting architecture of the LT1611 can generate a

very low ripple output voltage. Recently available high

value ceramic capacitors can be used successfully in

LT1611 designs with the addition of a phase lead capaci-

tor, CPL (see Figure 7). Connected in parallel with feedback

resistor R1, this capacitor reduces both output perturba-

tions due to load steps and output ripple voltage to very

low levels. To illustrate, Figure 7 shows an LT1611 invert-

ing converter with resistor loads RL1 and RL2. RL1 is

connected across the output, while RL2 is switched in

externally via a pulse generator. Output voltage wave-

forms are pictured in subsequent figures, illustrating the

performance of output capacitor type and the effect of CPL

connected across R1.

6

Share Link: