1/17

Step-Up DC/DC Controller IC, MAXDUTY: 93%

XC9122D091 (100kHz, 15.0V)

0

20

40

60

80

100

0.1

1

10

100

Output Current: IOUT(mA)

VIN=2.7V

L=47uH(CDRH5D28),SD:XB01SB04A2

CL=40uF(Ceramic),Tr:161A11A1

3.2V

4.2V

3.6V

PWM/PFM

PWM

■GENERAL DESCRIPTION

XC9120/9121/9122 Series are PWM, PWM/PFM auto/external switching controlled step-up DC/DC converter controller ICs.

Since maximum duty ratio is as large as 93%, the series is the best for the applications used as high step-up ratios, such as

the LCD panels and OLED. In this series, even if it is a high step-up ratio, the output voltage stabilized at high efficiency can

be obtained. With 0.9V (±2.0%) of reference voltage supply internal, and using external resistors, RFB1 and 2, output

voltage can be set up freely within a range of 1.5V to 30V. For a current sense, with the use of RSENSE, ceramic capacitors

can be used as load capacitors and allows for lower output ripple and reduced PCB area requirements.

Control automatically switches from PWM to PFM during light loads with the XC9121 series and the XC9122 series can

switch the control from PWM to PFM using external signals depending on the circuit conditions..

During stand-by (when the CE pin is low), all circuits are shutdown to reduce current consumption to as low as 1.0μA or less.

The overcurrent limit circuit of this IC is designed to monitor the ripple voltage of the FB pin and operates the IC to stop when

the ripple voltage runs over 250mV. The IC resumes its operation with a toggle of the CE pin or by turning the power supply

back on.

■APPLICATIONS

●Power Supply for the LCDs.

●High Step-Up Ratio Equipment (OLED, etc.)

■TYPICAL APPLICATION CIRCUIT

■TYPICAL PERFORMANCE

CHARACTERISTICS

☆GO-Compatible

■FEATURES

Input Voltage Range

: 0.9V~6.0V

Operating Voltage Range

: 1.8V~6.0V

Output Voltage Range

: 1.5V~30V (externally set)

Reference voltage 0.9V (±2.0%)

Oscillation Frequency

: 100kHz (±15%)

Output Current

Control

: XC9120 (PWM)

: XC9121 (PWM/PFM Automatic)

: XC9122 (PWM/PFM Externally)

High Efficiency

: 85% (TYP.)

Stand-by Function

: ISTB=1.0

μA (MAX.)

Load Capacitors

: Low ESR capacitor compatible

Current Limiter

: Operates when ripple is 250mV

Maximum Duty Ratio

: 93% (TYP.) for High Step-up Ratio

Package

: SOT-25, USP-6C

* When using external components showing in the circuit below.

VOUT=15V

Nch Power

MOS FET

XP161A1355

RSENSE: 50mΩ

for Ceramic CL

SD:

XB01SB04A2

RFB1:

470kΩ

CFB: 33pF

CE

15

4

3

2

Ceramic CL:

10uF x 4

RFB2: 30kΩ

CIN

VIN=

2.7V~4.2V

L: 47uH

ETR0409 002