AS1331-BTDT-AD-1K - Austriamicrosystems

AS1331

300mA Buck-Boost Synchronous DC/DC Converters

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 1 - 16

Datasheet

1 General Description

This special device is a synchronous buck-boost DC/DC

converter which can handle input voltages above, below ,

or equal to the output voltage.

Due to the internal structure of the AS1331 which is

working continuously through all operation modes this

device is ideal for dual or triple cell alkaline/NiCad/NiMH

as well as single cell Li-Ion battery applications.

Because of the implemented Power Save Mode, the

solution footprint and the component count is minimized

and also over a wide range of load currents a high

conversion efficiency is provided.

The device includes two N-channel MOSFET switches

and two P-channel switches. Also following features are

implemented: a quiescent current of typically 22µA

(ideal for battery power applications), a shutdown

current less than 1µA, current limiting, thermal shutdown

and output disconnect.

The AS1331 is available in a 10-p in 3x3mm TDF N

package with fixed and adjustable output voltage.

2 Key Features

! Input Voltage Range: 1.8V to 5.5V

! Output Voltages:

- Fixed: 2.5V, 3.0V, 3.3V

- Adjustable: 2.5V to 3.3V

! Output Current: 300mA @ 3.3V

! Up to 90% efficiency

! Power Good

! Output Disconnection in Shutdown

! Automatic transition between Buck and Boost mode

! Ultra Low Quiescent Current: 22µA, Shutdown Cur-

rent <1µA (Active Low)

! Short-Circuit Protection

! Low Battery detection

! Over Temperature Protection

! 10-pin 3x3mm TDFN package

3 Applications

The AS1331 is an ideal solution for handheld

computers, handheld instruments, portable musi c

players and PDA’ s. Two and three cell Alkaline, NiCd or

NiMH or single cell Li battery powered products.

Figure 1. AS1331 - Typical Application Diagram

1.8V to 5.5V

AS1331-AD C2

22µF

Off

10µF

PGND

SW2

VOUT

2.5V to 3.3V

VIN

VOUT

SW1

6.8µH

LBO

LBI

GND

Low Battery Detect

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 2 - 16

AS1331

Datasheet - Pin A s s i g n m e n t s

4 Pin Assignments

Figure 2. Pin Assignments (Top View)

Pin Descriptions

Table 1. Pin Descriptions

Name Pin

Number Description

VOUT 1Output of the Buck/Boos t Converter.

SW1 2Buck/Boost Switch Pin. Connect the inductor from SW1 to SW2

PGND 3Power Ground. Both GND pins must be connected.

SW2 4Buck/Boost Switch Pin. Connect the inductor from SW1 to SW2. An

optional Schottky diode can be connected between this pin and VOUT to

increase efficiency.

VIN 5Input Supply Pin. A minimum 2.2µF capacitor should be placed between

VIN and GND.

EN 6 Enable Pin. Logic controlled shutdown input.

1 = Normal operation;

0 = Shutdo w n ; qu i escent current <1µA.

LBI 7 Low Battery Comperator Input. 1.25V Threshold. May no t be left floating.

If connected to GND LBO is working as Output Power okay.

LBO 8 Low Battery Comperator Outp ut . This open-drain output is low when the

voltage on LBI is less than 1.25V.

GND 9 Ground. Both GND pins must be connected.

FB 10

Feedback Pin. Feedback input for the adjustable version. Connect a

resistor divider tap to this pin. The output voltage can be adjusted from 2.5V

to 3.3V by: VOUT = 1.25V[1 + (R1/R2)]

Note: For the fixed Output Voltage Version contact this pin to VOUT.

NC 11 Exposed Pad. This pad is not connected internally. It can be used for

ground connection between GND and PGND.

AS1331

SW2 2

SW1 4

VOUT 1

PGND 3

LBI

LBO

GND

VIN 5EN

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 3 - 16

AS1331

Datasheet - Ab so lu te Ma xi mu m R at in gs

5 Absolute Maximum Ratings

Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only,

and functional operation of the device at these or any other conditions beyond those indicated in Electrical

Characteristics on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may

affect device reliability.

Table 2. Absolute Maximum Ratings

Parameter Min Max Units Notes

SW1, SW2, VIN, VOUT, EN -0.3 +7 V

PGND to GND -0.3 +0.3 V

SW1, SW2 -0.3 +7 V

ESD 4 kV HBM MIL-Std. 883E 3015.7 methods

Thermal Resistance θJA +33 ºC/W

Junction Temperature +150 ºC

Operating Temperature Range -40 85 ºC

Storage Temperature Range -65 +125 ºC

Package Body Temperature +260 ºC

The reflow peak soldering temperature

(body temperature) specified is in

accordance with IPC/JEDEC J-STD-

020D “Moisture/Reflow Sensitivity

Classification for Non-Hermetic So lid

State Surfa ce Mount Devices”.

The lead finish for Pb-free leaded

packages is matte tin (100% Sn).

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 4 - 16

AS1331

Datasheet - Ele c t r i c a l C h a r a c t e r i s t i c s

6 Electrical Characteristics

VIN = 3.6V, VOUT = 3.3V, TAMB = -40°C to +85ºC. Typical values are at TAMB = +25ºC. Unless otherwise specified.

Table 3. Electrical Characteristics

Symbol Parameter Conditions Min Typ Max Units

Input

VIN Input Voltage Range 1.8 5.5 V

Minimum Startup Voltage ILOAD < 1mA 1.6 1.8 V

VUV Undervoltage Lockout

Threshold1VIN decreasing 1.5 1.6 1.7 V

Regulation

VOUT

Output Voltage Adjustable

Version 2.50 3.30 V

Output Voltage 3.3V

No Load

3.201 3.3 3.399 V

Output Voltage 3.0V 2.910 3.0 3.090 V

Output Voltage 2.5V 2.425 2.5 2.575 V

VFB FB Voltage Adjustable version No Load 1.212 1.25 1.288 V

IFB FB Input Current Adjustable

Version VFB = 1.3V, TAMB = 25°C 1 100 nA

VOUT Lockout Threshold2Rising Edge 2.0 2.15 2.3 V

Operating Current

IQQuiescent Current VIN VIN = 5V 26µA

Quiescent Current VOUT VIN = 5V, VOUT = 3.6V, VFB = 1.3V 20 32 µA

ISHDN Shutdown Current EN = 0V, VOUT = 0V, TAMB = +25ºC 0.01 1 µA

Switches

IMOS MOS Switch Leakage VIN = 5V, TAMB=25°C, Switches A-D 0.01 1 µA

RON

NMOS B, C VIN = 5V 0.13 Ω

PMOS A VIN = 5V 0.17 Ω

PMOS D VOUT = 3.3V 0.21 Ω

IPEAK Peak Cur ren t Li mi t L = 6.8µH, VIN = 5V 450 600 750 mA

Enable

VENH EN Input High 1.4 V

VENL EN Input Low 0.4 V

IEN EN Input Current EN = 5.5V, TAMB = 25°C 1 100 nA

Low Battery & Power-OK

VLBI LBI Threshold Falling Edge 1.212 1.25 1.288 V

LBI Hysteresis 10 mV

LBI Leakage Current LBI = 5.5V, TAMB = 25°C 1 100 nA

LBO Voltage Low3ILBO = 1mA 0.05 0.2 V

LBO Leakage Current LBO = 5.5V, TAMB = 25°C 1 100 nA

Power-OK Threshold LBI = 0V, Falling Edge 90 92.5 95 %

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 5 - 16

AS1331

Datasheet - Ele c t r i c a l C h a r a c t e r i s t i c s

Note: All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or

SQC (Statistical Quality Control) methods.

Thermal Protection

Thermal Shutdown 10°C Hysteresis 145 °C

1. If the input voltage falls below this value during normal operation the device goes in startup mode.

2. The regulator is in startup mode until this voltage is reached. Caution: Do not apply full load current until the

device output > 2.3V

3. LBO goes low in startup mode as well as during normal opera tion if:

1) The voltage at the LBI pin is below LBI threshold.

2) The voltage at the LBI pin is below 0.1V and VOUT is below 92.5% of its nominal value.

Table 3. Electrical Characteristics

Symbol Parameter Conditions Min Typ Max Units

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 6 - 16

AS1331

Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s

7 Typical Operating Characteristics

Circuit of Figure 24 on page 12, VIN = 2.4V, VOUT = 3.3V, TAMB = +25°C, unless otherwise specified.

Figure 3. Efficiency vs. Output Current; VOUT = 2.5V Figure 4. Efficiency vs. Output Current; VOUT = 3.0V

100

0.1 1 10 100 1000

Output Current (mA )

Efficiency (%)

Vin = 1.8V

Vin = 3.6V

Vin = 5.5V

100

0.1 1 10 100 1000

Output Current (mA )

Efficiency (%)

Vin = 1.8V

Vin = 3.6V

Vin = 5.5V

Figure 5. Efficiency vs. Output Current; VOUT = 3.3V Figure 6. Efficiency vs. Input Voltage

100

0.1 1 10 100 1000

Output Current (mA )

Efficiency (%)

Vin = 1.8V

Vin = 3.6V

Vin = 5.5V

100

1.8 2.2 2.6 3.0 3.4 3.8 4.2 4.6 5.0 5.4

Input Volt age ( V)

Efficiency (%)

Iout = 10m A

Iout = 100m A

Iout = 300m A

Figure 7. IOUT max vs. Input Voltage Figure 8. Sleep Currents vs. Input Voltage

100

200

300

400

500

1.8 2.2 2.6 3.0 3.4 3.8 4.2 4.6 5.0 5.4

Input Volt age ( V)

O ut put Current max (mA)

1.8 2.2 2.6 3.0 3.4 3.8 4.2 4.6 5.0 5.4

I n put Voltage (V)

Sleep Current (µA)

IVIN

IVOUT

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 7 - 16

AS1331

Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s

Figure 9. IIN Short Circuit vs. Input Voltage Figure 10. VOUT Ripple vs. Input Voltage

1.8 2.2 2.6 3.0 3.4 3.8 4.2 4.6 5.0 5.4

I n put Voltage (V)

I nput Current (mA)

100

150

200

250

1.5 2 2.5 3 3.5 4 4.5 5 5.5

Input Volt age ( V)

Vout Ripple V olt age ( m V )

10uF / Vpp

22uF / Vpp

47uF / Vpp

Figure 11. Load Regulation vs. Load Current Figure 12. VOUT Regulation vs. Tempera tu r e

3.24

3.26

3.28

3.3

3.32

3.34

3.36

3.38

0.1 1 10 100 1000

Load Cur rent (mA)

Output Voltage ( V )

Vout - 10uF

Vout - 22uF

Vout - 47uF 2

2.25

2.5

2.75

3.25

3.5

-45 -30 -15 0 15 30 45 60 75 90

T emperat ur e (° C)

Output Voltage ( V )

VOUT = 3.3V

VOUT = 3.0V

VOUT = 2.5V

Figure 13. IFB vs. Temperature; VIN = 5V Figure 14. EN Pin Threshold

-0.2

-0.1

0.1

0.2

0.3

0.4

-45 -30 -15 0 15 30 45 60 75 90

Temper ature (°C)

F B Input Current (µA)

3.6V

5.0V

5.5V

0.6

0.7

0.8

0.9

-45 -30 -15 0 15 30 45 60 75 90

Temper ature ( °C)

Thres hold V oltage ( V )

up-ON

down-OFF

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 8 - 16

AS1331

Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s

Figure 15. VIN = 4.4V, VOUT = 3.3V, IOUT = 200mA Figure 16. VIN = 4.4V, VOUT = 3.3V, IOUT = 50mA

5µs/Div

5V/Div

200mV/Div

SW2

ICOIL SW1VOUT

5V/Div

200mA/Div

5µs/Div

5V/Div

200mV/Div

SW2

ICOIL SW1VOUT

5V/Div

200mA/Div

Figure 17. VIN = 3.6V, VOUT = 3.3V, IOUT = 200mA Figure 18. VIN = 3.6V, VOUT = 3.3V, IOUT = 50mA

5µs/Div

5V/Div

200mV/Div

SW2

ICOIL SW1VOUT

5V/Div

200mA/Div

5µs/Div

5V/Div

200mV/Div

SW2

ICOIL SW1VOUT

5V/Div

200mA/Div

Figure 19. VIN = 2.5V, VOUT = 3.3V, IOUT = 200mA Figure 20. VIN = 2.5V, VOUT = 3.3V, IOUT = 50mA

5µs/Div

5V/Div

200mV/Div

SW2

ICOIL SW1VOUT

5V/Div

200mA/Div

5µs/Div

5V/Div

200mV/Div

SW2

ICOIL SW1VOUT

5V/Div

200mA/Div

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 9 - 16

AS1331

Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s

Figure 21. Shorted Output; VIN = 3.6V Figure 22. Startup; VIN = 3.6V, Rload = 3.3kΩ

1µs/Div

5V/Div

200mV/Div

SW2

ICOIL SW1VOUT

5V/Div

200mA/Div

500µs/Div

5V/Div

2V/Div

SW2

ICOIL SW1VOUT

5V/Div

200mA/Div

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 10 - 16

AS1331

Datasheet - D et a i l e d De s c r i p t i o n

8 Detailed Description

The synchronous buck-boost converter AS1331 uses a Power Save Mode control technique to reach a high efficiency

over a wide dynamic range of load currents. The output voltage is monit ored by a comparator with 3% accuracy. The

Power Save Mode puts the device into “sleep mode” when VOUT is above its programmed reference thresh old.

Meaning, the switching is stopped and only quiescent current is drawn from the power source. The switching is started

again when VOUT drops below the referen c e threshold and the out put capacitor is charged again.

The numbers of current pulses which are necessary to load the output capacitor are set by the value of the output

capacitor, the load current, and the comparator hysteresis (~1%).

Figure 23. AS1331 - Block Diagram - Fixed Output Voltage

Modes of Operation

When VOUT drops below the reference threshold, the AS1331 switches on the transist ors SW A and SW C until the

inductor current reaches app roximately 400mA. In the next step SW A and SW D are closed and depending on the

difference between VIN and VOUT the inductor current raises, falls or stays constant.

VIN > VOUT: The inductor current is going up to 600mA.

VIN ~ VOUT: The device stops after 2µs.

VIN < VOUT: The inductor current falls down to 0mA.

If the inductor current is not 0mA, the transistors SW B and SW D are closed to ramp down the current to zero. If VOUT

is still below the threshold voltage the next cycle is started. If I MAX (600mA) wasn’t reached in the previous cycle, SW A

and SW D are closed until the inductor current is 600mA.

Note: The 4-switch-mode (SW A+SW C => SW B+SW D => SW A + SW C...) and also the buck-mode (SW A+SW D

=> SW B+SW D => SW A+SW D...) are never used.

Start-Up Mode

At start-up the switch SW D is disabled and its diode is used to transfer current to the output capacitor until VOUT

reaches approximately 2.15V. The inductor current is controlled by an alternate algorithm during start-up.

Note: Do not apply loads >1mA until VOUT = 2.3V is reached.

VIN

SW1 SW2

SW A

SW B

SW C

SW D

VIN

1.6V

600mA

VOUT

PGND GND

Peak

Current

Limit

UVLO

State

Machine

and

Logic

VBEST

Gate Drivers

and

Anticross

Conduction IZERO

Detect

1.25V

Thermal Shutdown

Shutdown

VOUT

VBEST

VOUT

Comp

AS1331

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 11 - 16

AS1331

Datasheet - D et a i l e d De s c r i p t i o n

Other AS1331 Features

Shutdown

The part is in shutdown mode while the voltage at pin EN is below 0.4V and is active when the voltage is higher than

1.4V.

Note: EN can be driven above VIN or VOUT, as long as it is limited to less than 5.5V.

Output Disconnect and Inrush Limiting

During shutdown VOUT is going to 0V so that no current from the input source is running thru the device. The inrush

current is also limited at turn-on mode to minimize the surge currents seen by the input supply. These features of the

AS1331 are realized by opening both P-channel MOSFETs of the rectifiers, allowing a t ru e output disconnect.

Power-OK and Low-Battery-Detect Functionality

LBO goes low in startup mode as well as during normal operation if:

- The voltage at the LBI pin is below LBI thresho ld (1.25V). This can be used to monitor the battery voltage.

- LBI pin is connected to GND and VOUT is belo w 92.5% of its nominal value. LBO works as a power-OK signal in

this case.

The LBI pin can be connected to a resistive-divider to monitor a particular definable voltage and compare it with a

1.25V internal reference. If LBI is connected to GND an internal resistive-divider is activated and connected to the

output. Therefore, the Power-OK functionality can be realised with no addition al external components.

The Power-OK feature is not active during shutdown and provides a power-on-reset function that can operate down to

VIN = 1.8V. A capacitor to GND may be added to generate a power-on-reset delay. To obtain a logic-level output,

connect a pull-up resistor from pin LBO to pin VOUT. Larger values for this resistor will help to minimize current

consumption; a 100k Ω resist or is perf ect for most applications (see Figure 25 on page 12).

For the circuit shown in the left of Figure 24 on page 12, the input bias current into LBI is very low, permitting large-

value resistor-divider networks while maintaining accuracy. Place the resistor-divider network as close to the device as

possible. Use a defin ed resistor for R5 and then calculate R 4 as:

Where:

VLBI (the internal sense reference voltage) is 1.25V.

In case of the LBI pin is connecte d to GND, an internal re sistor-devider network is act ivated and compares the output

voltage with a 92.5% voltage threshold. For this particular Power-OK application, no external resistive components are

necessary.

Thermal Shutdown

To prevent the AS1331 from short-term misuse and overload conditi ons the chip includes a thermal overl oad

protection. To block the normal operation mode all switches will be turned off. The device is in thermal shutdown when

the junction temperature exceeds 145°C. To resume the normal operation the temperature has to drop below 135°C.

A good thermal path has to be provided to dissipate the heat generated within the package. Otherwise it’s not possible

to operate the AS1331 at its useable maximal power. To dissipate as much heat as possible away from the package

into a copper plane with as much area as possible, it’s recommended to use multiple vias in the prin ted circuit board.

It’s also recommended to solder the Exposed Pad (pin 11) to the GND plane.

Note: Continuing operation in t hermal overload conditions may damage the device and is considered bad practice.

(EQ 1)

R4R5VIN

VLBI

----------- 1–

⎝⎠

⎛⎞

⋅=

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 12 - 16

AS1331

Datasheet - D et a i l e d De s c r i p t i o n

Output Voltage Selection

The AS1331 is available in two versions (see Ordering Information on page 15). One version can only operate at one

fixed output voltage (see Figure 25) and the other version can operate with user-adjustable output voltages from 2.5V

to 3.3V by connecting a voltage divider between the pins VOUT and FB (see Figure 24).

Figure 24. LiIon to Adjustable Output Voltage

The output voltage can be adjusted by select ing different values for R1 and R2.

Calculate VOUT by:

Where:

VFB = 1.25V, VOUT = 2.5V to 3.3V;

R2 (the predefined resistor in th e resistor devider) should be ≤ 270kΩ.

R3 (the Pull-up resistor for the LBO pin) should be ~100k Ω.

Figure 25. LiIon to 3.3V with POK - Fixed Output Voltage

LiIon Battery

AS1331-AD C2

22µF

Off

10µF

PGND

SW2

VOUT

2.5V to 3.3V

VIN

VOUT

SW1

6.8µH

LBO

LBI

GND

(EQ 2)

VOUT VFB 1R1

------

⎝⎠

⎛⎞

×=

LiIon Battery

AS1331-

3.3V C2

22µF

Off

10µF

PGND

SW2

VOUT

3.3V

300mA

VIN

VOUT

SW1

6.8µH

LBO

LBI

GND9

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 13 - 16

AS1331

Datasheet - App l i c a t i o n I n f o r m a t i o n

9 Application Information

Component Selection

Only three power components are required to complete the design of the buck-boost converter. For the adjustable

version VOUT programming resistors are needed. The high operating frequency and low peak currents of the AS1331

allow the use of low value, low prof ile inductors and tiny external ceramic capacitors.

Inductor Selection

For best efficiency, choose an inductor with high frequency core material, such as ferrite, to reduce core losses. The

inductor should have low DCR (DC resistance) to reduce the I²R losses, and must be able to handle the peak inductor

current without saturating. A 6.8µH inductor with a >600mA current rating and <400mΩ DCR is recommended.

Capacitor Selection

The buck-boost convertor requires two capacitors. Ceramic X5 R or X7R types will minimize ESL and ESR while

maintaining capacitance at rated voltage over temperature. The VIN capacitor should be at least 2.2µF. The VOUT

capacitor should be between 10µF and 47µF. A larger output capacitor should be used if lower peak to peak out put

voltage ripple is desired. A larger outpu t capacitor will also improve load regulation on VOUT. See Table 5 for a list of

capacitors for input and output capacitor selection.

Table 4. Recommended Inductors

Part Number LDCR Current Rating Dimensions (L/W/T) Manufacturer

LPS3015-682M 6.8µH 300mΩ0.89A 3.0x3.0x1.5mm Coilcraft

www.coilcraft.com

EPL2014-682M 6.8µH 287mΩ0.80A 2.0x2.0x1.4mm

XPL2010-682M 6.8µH 336mΩ0.73A 2.0x1.9x1.0mm

Table 5. Recommended Input Capacitor

Part Number CTC Code Rated Voltage Dimensions (L/W/T) Manufacturer

GRM188R61A225KE34 2.2µF X5R 10V 0603, T=0.87mm Murata

www.murata.com

GRM188R60J475KE19 4.7µF X5R 6.3V 0603, T=0.87mm

GRM219R60J106KE19 10µF X5R 6.3V 0805, T=0.95mm

Table 6. Recommended Output Capacitor

Part Number CTC Code Rated Voltage Dimensions (L/W/T) Manufacturer

GRM21BR61A106KE19 10µF X5R 10V 0805, T=1.35mm Murata

www.murata.com

GRM319R61A106KE19 10µF X5R 10V 1206, T=0. 95mm

GRM319R61A106KE19 10µF X5R 10V 1210, T=0. 95mm

GRM31CR61C226KE15 22µF X5R 16V 1206, T=1.8mm

GRM31CR60J475ME19 47µF X5R 6.3V 1206, T=1.75mm

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 14 - 16

AS1331

Datasheet - Pa ck ag e D ra wi ng s a nd Markin gs

10 Package Drawings and Markings

The device is available in a 10-pin 3x3mm TDFN package.

Figure 26. 10-pin 3x3mm TDFN package Diagram

Note:

1. Figure 26 is shown for illustration only.

2. All dimensions are in millimeters, angle is in degrees.

3. Dimensioning and toleran c ing conform to ASME Y14.5M-1994.

4. N is the total number of terminals.

5. Terminal #1 identifier and terminal numbering convention shall conform to JESD 95-1 SPP-012. Details of ter-

minal #1 identifier are optional, but must be located within the area indicated. The terminal #1 identifier may be

either a mold, embedded metal or mark feature.

6. Dimension b applies to metallized terminal and is measured between 0.15 and 0.30mm from te rminal tip.

7. ND refers to the maximum number of terminals on D side.

8. Unilateral coplanarity zone applies to the exposed heat sink sl ug as well as the terminals.

Table 7. 10-pin 3x3mm TDFN package Dimensions

Symbol Min Typ Max Symbol Min Typ Max

A 0.70 0.75 0.80 D BSC 3.00

A1 0.00 0.02 0. 05 E BSC 3.00

A3 0.20 REF D2 2.20 2.70

L1 0.03 0.15 E2 1.40 1.75

L2 0.13 L 0.30 0.40 0.50

aaa 0.15 K 0.20

bbb 0.10 b 0.18 0.25 0.30

ccc 0.10 e 0.50

ddd 0.05 N 10

eee 0.08 ND 5

ggg 0.10 θ0°14°

SEE

DETAIL B

PIN 1 INDEX AREA

(D/2 xE/2)

BTM VIEW

N-1N

ddd

D2/2

(D/2 xE/2)

TOP VIEW

aaa C

PIN 1 INDEX AREA

ccc C

SIDE VIEW

(ND-1) X e

0.08 C

C A B

E2/2

SEATING

PLANE

DETAIL B

Datum A or B

Terminal Tip

ODD T ERMINA L SIDE

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 15 - 16

AS1331

Datasheet - O r d e r i n g I n f o r m a t i o n

11 Ordering Information

The device is available as the standard products shown in Table 8.

* on request

Note: All products are RoHS compliant and Pb-free.

Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect

For further info rmation and requests, please contact us mailto:sales@austriamicrosystems.com

or find your local distribu tor at http://www.austriamicrosystems.com/distributor

Table 8. Ordering Information

Ordering Code Marking Output Description Delivery Form Package

AS1331-BTDT-AD ASRP adjustable 300mA Buck-Boost

Synchronous DC/DC Converters Tape and Reel 10-pin 3x3mm TDFN

AS1331-BTDT-25* ASRR 2.5V 300mA Buck-Boost

Synchronous DC/DC Converters Tape and Reel 10-pin 3x3mm TDFN

AS1331-BTDT-30* ASRT 3.0V 300mA Buck-Boost

Synchronous DC/DC Converters Tape and Reel 10-pin 3x3mm TDFN

AS1331-BTDT-33 ASRU 3.3V 300mA Buck-Boost

Synchronous DC/DC Converters Tape and Reel 10-pin 3x3mm TDFN

www.austriamicrosystems.com/DC-DC_Buck-Boost/AS1331 Revision 1.04 16 - 16

AS1331

Datasheet

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Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing

in its Term of Sale. austriamicrosystems AG makes no warranty, express, st atutory, implied, or by description regarding

the information set forth herein or regarding the freedom of the described devices from patent infringement.

austriamicrosyst ems AG reserves the right to change specifications and prices at any time and without notice.

Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for

current information. This product is intended for use in normal commercial applications. Applications requiring

extended temperature range, unusual environmental requirements, or high reliability ap plications, such as military,

medical life-support or life-sustaining equipment are specifically not recommended without additional processing by

austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show

deviations from the standard production flow, such as test flow or test location.

The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However,

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Tel: +43 (0) 3136 500 0

Fax: +43 (0) 3136 525 01

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