20 V,1.2 MHz Step-Up

DC-to-DC Switching Converter

ADP1611

Rev. 0

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FEATURES

Fully integrated 1.2 A , 0.23 Ω power switch

Pin-selectable 700 kHz or 1.2 MHz PWM frequency

90% efficiency

Adjustable output voltage up to 20 V

3% output regulation accuracy

Adjustable soft start

Input undervoltage lockout

MSOP 8-lead package

APPLICATIONS

TFT LC bias supplies

Portable applications

Industrial/instrumentation equipment

GENERAL DESCRIPTION

The ADP1611 is a step-up dc-to-dc switching converter with an

integrated 1.2 A, 0.23 Ω power switch capable of providing an

output voltage as high as 20 V. With a package height of less

than 1.1 mm, the ADP1611 is optimal for space-constrained

applications such as portable devices or thin film transistor

(TFT) liquid crystal displays (LCDs).

The ADP1611 operates in pulse-width modulation (PWM)

current mode with up to 90% efficiency. Adjustable soft start

prevents inrush currents at startup. The pin-selectable switching

frequency and PWM current-mode architecture allow excellent

transient response, easy noise filtering, and the use of small,

cost-saving external inductors and capacitors.

The ADP1611 is offered in the Pb-free 8-lead MSOP and

operates over the temperature range of −40°C to +85°C.

FUNCTIONAL BLOCK DIAGRAM

REF

RAMP

GEN

RT

DRIVER

CURRENT-

SENSE

AMPLIFIER

COMP

SW

FB

IN

COMPARATOR

ERROR

AMP

GND

BIAS

SD

OSC

ADP1611

Q

S

R

F/F

2

7

3

5

4

1

6

8

SOFT START

SS

Figure 1.