UTCUT2306/UT2306-3.3V/UT2306-5.0V

LINEAR INTEGRATED CIRCUIT

3

QW-R103-029,A

The * denotes specifications which apply over the 0

°C to 70°C operating temperature range.

PIN FUNCTIONS

PIN No.

SYMBOL

DESCRIPTION

1

LBI

Low Battery Detector Input. When voltage on this pin is less than

1.17V,detector output is low

2

LBO

Low Battery Detector Output. Open collector can sink up to 500µA.Low

battery detector remains active when device is shut down.

3

Input Supply. Must be bypassed close (<0.2”) to the pin. See required layout

in the Typical Applications

4

SW

Collector of Power NPN. Keep copper traces on this pin short and direct to

minimize RFI

5

GND

Device Ground. Must be low impedance; solder directly to ground plane

6

Current Limit Set Pin. Float for 1A peak switch current; a resistor to ground

will lower peak current

7

SHDN

Shutdown Input. When low, switching regulator is turned off. The

low-battery detector remains active. The SHDN input should not be left

8

FB/SENSE

On the UT2306 (adjustable) this pin goes to the comparator input. On the

fixed-output versions, the pin connects to the resistor divider which sets output

voltage. The divider is disconnected from the pin during shutdown.

TYPICAL APPLICATION

+

VIN

SW

LBI

SENSE

ILIM

IBO

SHDN

GND

7

100μF

5V

200mA

2 CELLS

22μH

UT2306-5.0

2-Cell to 5V Step-Up Converter with Low-Battery Detect

499K

604K

SHUTDOWN

1

6

NC

3

4

5

8

2

100K

100μF

+

LBO

LOW WHEN

VBAT＜2.2V

D1

90

LOAD CURRENT(mA)

Efficiency

1

10

100 500

0.01

80

70

60

50

40

V IN =3.3V

V IN =2.5V

V IN =1.8V

1N5817