R1211D103C datasheet(12/40 Pages) RICOH

tên linh kiện	R1211D103C

Giải thích chi tiết về linh kiện	STEP-UP DC/DC CONTROLLER

PDF	40 Pages

Scroll/Zoom	100%

nhà sản xuất	RICOH [RICOH electronics devices division]

Trang chủ	http://www.ricoh.com

Logo

12 / 40 page

R1211x

TIMING CHART

• R1211x002A/R1211x002C

VOUT

VFB

VREF

AMPOUT

DTC

EXT

PWM Comparator

EXT

OP AMP

• R1211x002B/R1211x002D

VOUT

VFB

VREF

AMPOUT

DTC

EXT

PWM Comparator

EXT

OP AMP

<Soft-start Operation>

Soft-start operation is starting from power-on as follows:

(Step1)

The voltage level of SS is rising gradually by constant current circuit of the IC and a capacitor. VREF level which

is input to OP AMP is also gradually rising. VOUT is rising up to input voltage level just after the power-on,

therefore, VFB voltage is rising up to the setting voltage with input voltage and the ration of R1 and R2. AMPOUT

is at "L", and switching does not start.

(Step2)

When the voltage level of SS becomes the setting voltage with the ration of R1 and R2 or more, switching

operation starts. VREF level gradually increases together with SS level. VOUT is also rising with balancing VREF and

VFB. Duty cycle depends on the lowest level among AMPOUT, SS, and DTC of the 4 input terminals in the PWM

comparator.

R1211D103C bảng dữ liệu(PDF) 12 Page - RICOH electronics devices division