RT9261-35GB - Richtek - Datasheet.Directory

RT9261/A

DS9261/A-16 April 2011 www.richtek.com

Pin Configurations

VFM Step-Up DC/DC Converter

Ordering Information

General Description

The RT9261 Series are VFM Step-up DC/DC ICs with ultra

low supply current by CMOS process and suitable for

use with battery-powered instruments.

The RT9261 IC consists of an oscillator, a VFM control

circuit, a driver transistor (LX switch), a reference voltage

unit, an error a mplifier , resistors for voltage detection, and

a LX switch protection circuit. A low ripple and high

efficiency step-up DC/DC converter can be constructed of

this RT9261 IC with only three external components.

The RT9261A IC provides with a drive pin (EXT) for an

external transistor, so that a power transistor can be

externally applied. Therefore, the RT9261A IC is

recommended f or a pplication s where large currents are

required. EN pin enables circuit to set the standby supply

current at a maximum of 0.5μA.

Features

zMinimal Number of External Components ( Only

an Inductor, a Diode, and a Capacitor)

zUltra Low Input Current ( 5μμ

μμ

μA at Switch Off)

z±±

±±

±2% High Output V oltage Accura cy

zLow Ripple and Low Noise

zLow Start-up Voltage, 0.85V at 1mA

z75% Efficiency with Low Cost Inductor

z+50 ppm/ °°

°°

°C Low Temperature-Drift

zSOT-89 and SOT-23-5 Small Pa c kages

zRoHS Compliant and 100% Lead (Pb)-Free

Applications

zPower source for battery-powered equipment

zPower source for ca meras, ca mcorders, VCRs, PDAs,

pagers, electronic data ba nks, and hand-held

communication equipment

zPower source for applications, which require higher

voltage tha n that of batteries used in the a ppliances

(TOP VIEW)

SOT-89

Marking Information

For marking information, contact our sales representative

directly or through a Richtek distributor located in your

area.

GND VOUT

(TAB) LX

123

RT9261

GND VOUT

(TAB) EXT

123

RT9261A

Note :

Richtek products are :

` RoHS compliant and compatible with the current require-

ments of IPC/JEDEC J-STD-020.

` Suitable for use in SnPb or Pb-free soldering processes.

SOT-23-5

RT9261ART9261

EN VOUT NC

LX GND

EN VOUT NC

EXT GND

RT9261/A-

Package Type

B : SOT-23-5

X : SOT-89

Lead Plating System

P : Pb Free

G : Green (Halogen Free and Pb Free)

Output Voltage

15 : 1.5V

16 : 1.6V

49 : 4.9V

50 : 5.0V

Use external switch

Use internal switch

RT9261/A

2DS9261/A-16 April 2011www.richtek.com

Typical Application Circuit

Figure 1 Figure 2

Figure 3 Figure 4

Figure 5

VOUTLX GND

RT9261xX

1N5819

VOUT

100µH

VIN COUT

22µF

VOUTEXT GND

RT9261AxX

1N5819

VOUT

27µH

VIN COUT

22µF

0.01µF

300

ZTX

650 Tr

VIN

VOUT

GND

RT9261xB

1N5819

VOUT

100µH COUT

22µF

NC VOUT

EXT

GND

RT9261AxB

1N5819

VOUT

27µH

VIN COUT

22µF

0.01µF

300

ZTX

650 Tr EN

VOUT

GND

RT9261xB

1N5819

VOUT

27µH

VIN COUT

22µF

Chip

Enable

RT9261/A

DS9261/A-16 April 2011 www.richtek.com

Functional Pin Description

Function Block Diagram

Pin No . Pi n Name Pin Func t ion

RT9261-□□□X RT9261A-□□□X RT9261-□□□B RT9261 A-□□□B

1 1 4 4 GND Ground.

2 2 2 2 VOUT Output Voltage.

3 -- 5 -- LX Pin for Switching.

-- 3 -- 5 EXT Drive External Device.

-- -- 1 1 EN Chip Enable (Active High).

-- -- 3 3 NC No Internal Connected.

VLX Limiter

Buffer

Chip Enable

VFM Control +

Error

Amplifier

VREF

VOUT

LXSW

GND

EXT

OSC 100kHz

Notes:(1) LX Pin...... only for 9261- xX a nd 9261- xB

(2) EXT Pin.... only f or 9261A- xX and 9261A- xB

(3) EN Pin...... only f or 9261- xB and 9261A- xB

RT9261/A

4DS9261/A-16 April 2011www.richtek.com

Electrical Characteristics (Refer to Figure 1)

Parameter Symbol Test Conditions Min Typ Max Unit

Output Voltage Accuracy ΔVOUT −2 -- 2 %

In put Voltage VIN -- -- 7 V

St ar t - up Vo l t a g e VST I

OUT = 1mA, VIN: 0 → 2V -- 0.85 1 V

Hold-on Volta ge VHO I

OUT = 1mA, VIN: 2 → 0V 0.7 -- -- V

VOUT ≤ 3.5V (1) -- 15 18

In put Curr en t 1 VIN at no load 3.5V < VOUT ≤ 5V (2) -- 18 24

μA

In put Curr en t 2 VOUT in switch off condition -- 5 8 μA

VOUT ≤ 3.5V (1) 60 -- --

LX S wi tc hing Curre nt ISWITCHING V

LX = 0.4V 3.5V < VOUT ≤ 5V (2) 80 -- --

LX Lea ka ge Cu r ren t ILEAKAGE V

LX = 6V -- -- 0.5 μA

Maximum Oscillator FMAX 80 120 160 kHz

VOUT = 2.5V to 5V 65 75 85 %

Oscillator Duty Cycle DOSC On ( VLX ” L ” ) side VOUT = 1.5V to 2.4V 60 70 80 %

Efficiency -- 75 -- %

VLX Voltage Limit LX switch on 0.65 0.8 1 V

Notes:

(1)Unless otherwise provided, VIN = 1.8V, VSS = 0V, IOUT = 10mA, T OPT = 25°C, and External Circuit of Typical Application

(2)Unless otherwise provided, VIN = 3V, V SS = 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical Application

Absolute Maximum Ratings

zOutput V oltage ------------------------------------------------------------------------------------------------------ 8V

zLX Pin Voltage (1)------------------------------------------------------------------------------------8V

zEXT Pin V oltage (2) ------------------------------------------------------------------------------------------------- −0.3 to VOUT +0.3V

zEN Pin V oltage (3) --------------------------------------------------------------------------------------------------- −0.3 to VOUT +0.3V

zLX Pin Output Current (1) ------------------------------------------------------------------------------------------ 250mA

zEXT Pin Current (2) -------------------------------------------------------------------------------------------------- ±50mA

zPower Dissipation, PD @ TA = 25°C

SOT-89 ---------------------------------------------------------------------------------------------------------------- 0.5W

SOT-23-5-------------------------------------------------------------------------------------------------------------- 0.25W

zPackage Thermal Resistance

SOT-89, θJC ---------------------------------------------------------------------------------------------------------- 100°C/W

SOT-89, θJA ---------------------------------------------------------------------------------------------------------- 300°C/W

SOT-23-5, θJA -------------------------------------------------------------------------------------------------------- 250°C/W

zOperating T emperature Range ----------------------------------------------------------------------------------- −20 to +85°C

zStorage T emperature Range -------------------------------------------------------------------------------------- 165°C

zLead T emperature (Soldering, 10 sec.) ------------------------------------------------------------------------ 260°C

Notes:

(1) Applicable to R T9261- xX and RT9261- xB

(2) Applicable to R T9261A- xX and RT9261A- xB

(3) Applicable to R T9261- xB and RT9261A- xB

RT9261/A

DS9261/A-16 April 2011 www.richtek.com

Electrical Characteristics (Refer to Figure 2)

Parameter Symbol Test Conditions Min Typ Max Unit

Output Voltage Accuracy ΔVOUT −2 -- +2 %

In put Voltage VIN -- -- 7 V

St ar t - up Vo lt age V ST I

OUT = 1mA, VIN : 0 → 2V -- 0.85 1.0 V

VOUT ≤ 3.5V (1) -- 30 50

In put Curren t 1 VIN at no load 3.5V < VOUT ≤ 5V (2) -- 60 90

μA

VOUT ≤ 3.5V (1)

In put Curren t 2 VOUT in switch off

condition 3.5V < VOUT ≤ 5V (2) -- 6 10 μA

VOUT ≤ 3.5V (1) −1.5 -- --

EXT “H” Output Current VEXT = VOUT – 0.4V 3.5V < VOUT ≤ 5V (2) −2 -- --

VOUT ≤ 3.5V (1) 1.5 -- --

EXT “L” Output Current VEXT = 0. 4V 3.5V < VOUT ≤ 5V (2) 2 -- --

M axi m um Os ci llator Frequen cy FMAX 80 120 160 kHz

VOUT = 2.5V to 5V 65 75 85 %

Oscillator Duty Cycle DOSC V

EXT ” H ” si de VOUT = 1.5V to 2.4V 60 70 80 %

Notes:

(1)Unless otherwise provided, VIN = 1.8V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and use External Circuit of Typical

Application

(2)Unless otherwise provided, VIN = 3V, VSS= 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical Application

RT9261/A

6DS9261/A-16 April 2011www.richtek.com

Electrical Characteristics (Refer to Figure 3)

Parameter Symbol Test Conditions Min Typ Max Unit

O utput Voltag e Accuracy ΔVOUT −2 -- +2 %

Input Voltage VIN -- -- 7 V

Star t-up Voltage VST I

OUT = 1mA, VIN : 0 → 2V -- 0.85 1.0 V

Hold -on Voltage VHO I

OUT = 1mA, VIN : 2 → 0V 0.7 -- -- V

VOUT ≤ 3.5V (1) -- 75 --

Efficiency

3.5V < VOUT ≤ 5V (2) -- 85 -- %

VOUT ≤ 3.5V (1) -- 15 18

Input Current 1 VIN at no load 3.5V < VOUT ≤ 5V (2) -- 18 24

μA

VOUT ≤ 3.5V (1) -- 5 8

Input Current 2 VOUT in switch

off condition 3.5V < VOUT ≤ 5V (2) -- 6 10

μA

VOUT ≤ 3.5V (1) 60 -- --

LX Swit chin g Cu rrent ISWITCHING V

LX = 0.4V 3.5V < VOUT ≤ 5V (2) 80 -- -- mA

LX Leakage Current ILEAKAGE V

LX = 6V -- -- 0.5

μA

E N “H” Leve l VIN = VOUT × 0.9 0.4 x

VOUT -- -- V

EN “ L” Level VIN = VOUT × 0.9 -- -- 0.2 V

EN “ H” In pu t Curre n t EN = VOUT -- -- 0.5 μA

EN “ L“ Input Current EN = 0V −0.5 -- --

μA

Maximum Oscillat or F requen cy FMAX 80 120 160 kHz

VOUT = 2.5V to 5V 65 75 85 %

Oscillator Duty Cycle DOSC On (VLX ” L” )

side VOUT = 1.5V to 2.4V 60 70 80 %

VLX Voltage Limit LX switch on 0.65 0.8 1.0 V

Notes:

(1)Unless otherwise provided, VIN = 1.8V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and use External Circuit of Typical

Application

(2)Unless otherwise provided, VIN = 3V, VSS= 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical Application

RT9261/A

DS9261/A-16 April 2011 www.richtek.com

Parameter Symbol Test Conditions Min Typ Max Unit

Output Voltage A ccuracy ΔVOUT −2 -- +2 %

Input Voltage VIN -- -- 7 V

Start-up Voltage VST I

OUT = 1mA, VIN : 0 → 2V -- 0.85 1.0 V

VOUT ≤ 3.5V (1) -- 75 --

Efficiency

3.5V < VOUT ≤ 5V (2) -- 85 --

VOUT ≤ 3.5V (1) -- 30 50

Input Cur r e nt 1 VIN at no load 3.5V < VOUT ≤ 5V (2) -- 60 90

μA

VOUT ≤ 3.5V (1)

Input Cur r e nt 2 VOUT in switch

off condition 3.5V < VOUT ≤ 5V (2) -- 6 10 μA

VOUT ≤ 3.5V (1) −1.5 -- --

EXT “H” Output Current VEXT = VOUT –

0.4V 3.5V < VOUT ≤ 5V (2) −2 -- --

VOUT ≤ 3.5V (1) 1.5 -- --

EXT “L” Output Current VEXT = 0.4V 3.5V < VOUT ≤ 5V (2) 2 -- --

E N “H” Level VIN = VOUT × 0.9 0.4× VOUT -- -- V

EN “ L” Level VIN = VOUT × 0.9 -- -- 0.2 V

E N “ H” Input Cur r ent EN = VOUT -- -- 0.5 μA

E N “ L“ Input Current EN = 0V −0.5 -- -- μA

Maximum Oscillat or F requen cy FMAX 80 120 160 kHz

VOUT = 2.5V to 5V 65 75 85 %

Oscillator Duty Cycle DOSC On (VLX ” L” )

side VOUT = 1.5V to 2.4V 60 70 80 %

VLX Voltage Limit LX switch on 0.65 0.8 1.0 V

Electrical Characteristics (Refer to Figure 4)

Notes:

(1)Unless otherwise provided, VIN = 1.8V, VSS = 0V, I OUT = 10mA, TOPT = 25°C, and use External Circuit of Typical

Application

(2)Unless otherwise provided, VIN = 3V, VSS= 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical Application

RT9261/A

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Typical Operating Characteristics

Output Current vs. Ripple Voltage

100

120

0 20406080100

Output Current (mA)

Ripple Voltage (mV p-p)

RT9261

VOUT = 2.7V

2.5V

2.0V

1.5V

0.9V

Start-up/Hold-on Volta ge vs . Output Current

0.2

0.4

0.6

0.8

1.2

1.4

0 1020304050

Output Current (mA)

Start-up/ Hold-on V olt age

Vstart/Vhold (V)

Vstart

Vhold

RT9261

VOUT = 2.7V

Output Voltage vs. Output Current

0.5

1.5

2.5

020406080100

Output Current (mA)

Output Voltage (V )

RT9261

VOUT = 2.7V

2.5V

2.0V

1.5V

1.0V

0.9V

Output Voltage vs. Temperature

2.60

2.65

2.70

2.75

2.80

2.85

2.90

-40-200 20406080

Temperature

Output Voltage (V )

RT9261

VOUT = 2.7V

(°C)

Efficiency vs. Output Current

0 20406080100

Output Current (mA)

Efficiency (%)

RT9261

VOUT = 2.7V

2.5V

2.0V

1.5V

1.0V

0.9V

Supply Current vs. Temperature

-40-200 20406080

Temperature

Supply Current (uA)

RT9261

VOUT = 2.7V

Input Current 2

Input Current 1

(°C)

RT9261/A

DS9261/A-16 April 2011 www.richtek.com

Maximum Oscillator Frequenc y

vs. Temperature

100

120

140

160

-40 -20 0 20 40 60 80

Temperature

Maximum Oscillator Frequency (kHz ) A

RT9261

VOUT = 2.7V

(°C)

Output Voltage vs. Output Current

0.5

1.5

2.5

0306090120150

Output Current (mA)

Output Voltage (V)

RT9261A

VOUT = 2.7V

2.5V

1.5V

1.0V

0.9V 2.0V

Oscillator Duty Cycle vs. Temperature

100

-40-200 20406080

Temperature

Oscillator Dut y Cyc le (% )

RT9261

VOUT = 2.7V

(°C)

Efficiency vs. Output Current

0 306090120150

Output Current (mA)

Efficiency (%)

RT9261A

VOUT = 2.7V

2.5V

1.5V

1.0V

0.9V 2.0V

Start-up/Hold- o n V ol tage vs. Output Current

0.2

0.4

0.6

0.8

1.2

1.4

1.6

0 306090120150

Output Current (mA)

Start-up/ Hold-on V oltage1

Vstart/Vhold (V)

Vstart

Vhold

RT9261A

VOUT = 2.7V

Output Current vs. Ripple Voltage

100

120

0306090120150

Output Current (mA)

Ripple Voltage (mV p-p)

RT9261A

VOUT = 2.7V

2.5V

1.5V

0.9V

2.0V

RT9261/A

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Outline Dimension

AA1

SOT-23-5 Surface Mount Package

Dimensio ns In Millimeters Dimensions In Inches

Symbol Min Max Min Max

A 0.889 1.295 0.035 0.051

A1 0.000 0.152 0.000 0.006

B 1.397 1.803 0.055 0.071

b 0.356 0.559 0.014 0.022

C 2.591 2.997 0.102 0.118

D 2.692 3.099 0.106 0.122

e 0.838 1.041 0.033 0.041

H 0.080 0.254 0.003 0.010

L 0.300 0.610 0.012 0.024

RT9261/A

DS9261/A-16 April 2011 www.richtek.com

Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit

design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be

guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek.

Richtek Technology Corporation

Headquarter

5F, No. 20, Taiyuen Street, Chupei City

Hsinchu, Taiwan, R.O.C.

Tel: (8863)5526789 Fax: (8863)5526611

Richtek Technology Corporation

Taipei Office (Marketing)

5F, No. 95, Minchiuan Road, Hsintien City

Taipei County, Taiwan, R.O.C.

Tel: (8862)86672399 Fax: (8862)86672377

Email: marketing@richtek.com

3-Le ad SOT-89 Surfa ce Mount

Dim e nsions In Mi ll imete rs Dimen sions In I nc he s

Symbol Min Max Min Max

A 1.397 1.600 0.055 0.063

b 0.356 0.483 0.014 0.019

B 2.388 2.591 0.094 0.102

b1 0.406 0.533 0.016 0.021

C 3.937 4.242 0.155 0.167

C1 0.787 1.194 0.031 0.047

D 4.394 4.597 0.173 0.181

D1 1.397 1.753 0.055 0.069

e 1.448 1.549 0.057 0.061

H 0.356 0.432 0.014 0.017