AS1322B-BTTT - AMS AG - Product.Network

AS1322

Low Voltage, Micropower, DC-DC Step-Up Converters

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 1 - 18

Datasheet

1 General Description

The AS1322A and the AS1322B are synchronous, fixed frequency,

very high-efficiency DC-DC boost converters capable of supplying

3.3V at 150mA from a single AA-supply . Compact size and minimum

external parts requirements make these devices perfect for modern

portable devices.

High-speed switching frequency (1.2MHz) and internally

compensated PWM current mode design provide highly-reliable DC-

DC conversion, especially when driving white LEDs.

The converters are available as the standard products listed in Table

The devices contain two internal MOSFET switches: one NMOS

switch and one PMOS synchronous rectifier.

Anti-ringing control circuitry reduces EMI by damping the inductor in

discontinuous mode, and the devices exhibit extremely low

quiescent current (< 1µA) in shutdown.

In shutdown mode the battery is connected to the output and VOUT

is held at approximatel y VIN - 0.6V.

The AS1322 is available in a 6-pin TSOT-23 package.

Figure 1. Typical Application Diagram – Single Cell to 3.3V

Synchronous Boost Converter

2 Key Features

! 95% Efficiency

! Single-Cell Operation

! Delivers 160mA @ 3.3V (from Single AA Cell)

! Delivers 220mA @ 5.0V (from Two AA Cells)

! Delivers 570mA @ 3.3V (from Two AA Cells)

! Low Start-Up Voltage: 0.85V

! High-Speed Fixed-Frequency: 1.2MHz

! Internal PMOS Synchronous Rectifier

! Automatic Powersave Operation (AS1322A)

! Continuous Switching at Light Loads (AS1322B)

! Anti-Ringing Control Minimizes EMI

! Logic Controlled Shutdown (< 1µA)

! Output Range: 2.5 to 5.0V

! 6-pin TSOT-23 Pack age

3 Applications

The AS1322 is ideal for low-power applications where ultra-small

size is critical as in medical diagnostic equipment, hand-held

instruments, pagers, digital cameras, remote wireless transmitters,

MP3 players, LCD bias supplies, cordless phones, GPS receivers,

and PC cards.

Table 1. Standard Products

Model Light Load Switching

AS1322A Automatic Powersave Operation

AS1322B Continuous Switching

AA Battery

AS1322

10µF

604kΩ

1.02MΩ

Off

4.7µH

10µF

GND

VOUT

3.3V

160mA

SHDNN

VIN

VOUT

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 2 - 18

AS1322

Datasheet - Pin Assignments

4 Pin Assignments

Figure 2. Pin Assignments (Top View)

4.1 Pin Descriptions

Table 2. Pin Descriptions

Pin Number Pin Name Description

1SW

Switch Pin. Connect an inductor between this pin and VIN. Keep the PCB trace lengths as

short and wide as is practical to reduce EMI and voltage overshoot. If the inductor current

falls to zero, or pin SHDNN is low , an internal 100Ω anti-ringing switch is connected from this

pin to VIN to minimize EMI.

Note: An optional Schottky diode can be connected between this pin and VOUT.

2GND Signal and Power Ground. Provide a short, direct PCB path between this pin and the

negative side of the output capacitor(s).

3FB Feedback Pin. Feedback input to the gm error amplifier . Connect a resistor divider tap to this

pin. The output voltage can be adjusted from 2.5 to 5V by: VOUT = 1.23V[1 + (R1/R2)]

4SHDNN

Shutdown Pin. Logic controlled shutdown input.

1 = Normal operation, 1.2MHz typical operating frequency.

0 = Shutdown; quiescent current <1µA. If SHDNN is undefined, pin SW may ring.

Note: In a typical application, SHDNN should be connected to VIN through a 1MΩ pull-up

resistor.

5VOUT

Output Voltage Sense Input and Drain of the Internal PMOS Synchronous Rectifier.

Bias is derived from VOUT when VOUT exceeds VIN. PCB trace length from VOUT to the

output filter capacitor(s) should be as short and wide as is practical. VOUT is held at

approximately VIN - 0.6V during shutdown.

6VIN

Input Voltage. The AS1322 gets its start-up bias from VIN unless VOUT exceeds VIN, in

which case the bias is derived from VOUT. Thus, once started, operation is completely

independent from VIN. Operation is only limited by the output power level and the internal

series resistance of the supply.

AS1322

GND

6VIN

5VOUT

4SHDNN

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 3 - 18

AS1322

Datashee t - A b s o l u t e M a x i mu m R a t i n g s

5 Absolute Maximum Ratings

Stresses beyond those listed in Table 3 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 Section 6 Electrical Characteristics on page 4 is not implied. Exposure to

absolute maximum rating conditions for extended periods may affect device reliability.

Table 3. Absolute Maximum Ratings

Parameter Min Max Units Notes

VIN to GND -0.3 7 V

SHDNN, SW to GND -0.3 7 V

FB to GND -0.3 5 V

VOUT -0.3 7 V

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-020 “Moisture/Reflow Sensitivity

Classification for Non-Hermetic Solid State

Surface Mount Devices”.

The lead finish for Pb-free leaded packages is

matte tin (100% Sn).

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 4 - 18

AS1322

Datasheet - Electrical Characteristics

6 Electrical Characteristics

AMB

= -40 to +85ºC,

VIN

= +1.2V, V

OUT

= +3.3V,

VSHDNN

= +1.2V (unless otherwise specified). Ty p values @ T

AMB

= +25ºC.

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

Control) methods.

Table 4. Electrical Characteristics

Symbol Parameter Conditions Min Typ Max Units

Minimum Start-Up Voltage ILOAD = 1mA 0.85 1 V

Minimum Operating Voltage SHDNN = VIN 1

1. Minimum VIN operation after start-up is only limited by the battery’s ability to provide the necessary power as it enters a deeply dis-

charged state.

0.65 0.85 V

Output Voltage Adjust Range TAMB = 25ºC 2.5 5 V

VFB Feedback Voltage TAMB = TMIN to TMAX 1.192 1.23 1.268 V

IFB Feedback Input Current VFB = 1.25V 2

2. Specification is guaranteed by design and not 100% production tested.

1 nA

IQPWS Quiescent Current

(Powers ave Operation) VFB = 1.4V 3, AS1322A onl y

3. IQPWS is measured at VOUT. Multiply this value by VOUT/VIN to get the equivalent input (battery) current.

30 50 µA

IQSHDNN Quiescent Current (Shutdown) V SHDNN = 0V 0.01 1 µA

IQQuiescent Current (Active) VFB = 1.4V 3, AS1322B only 150 300 µA

INMOSSWL NMOS Switch Leakage VSW = 5V 0.1 5 µA

IPMOSSWL PMOS Switch Leakage VSW = 0V 0.1 5 µA

RONNMOS NMOS Switch On Resistance VOUT = 3.3V 0.35 0.8 Ω

VOUT = 5V 0.20 0.7

RONPMOS PMOS Switch On Resistance VOUT = 3.3V 0.45 0.8 Ω

VOUT = 5V 0.30 0.7

INMOS NMOS Current Limit VIN = 2.5V 850 mA

IPS Powersave Operation Current

Threshold AS1322A only 23 mA

Max Duty Cycle VFB = 1V, TAMB = TMIN to TMAX 80 87 %

fSW Switching Frequency TAMB = 25ºC 0.95 1.2 1.5 MHz

TAMB = TMIN to TMAX 0.85 1.2 1.5

VSHDNNH SHDNN Input High 1 V

VSHDNNL SHDNN Input Low 0.35 V

ISHDNN SHDNN Input Current VSHDNN = 5.0V 0.01 1 µA

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 5 - 18

AS1322

Datasheet - Typical Operating Characteristics

7 Typical Operating Characteristics

Figure 3. Powersave mode threshold vs. VIN, Figure 4. Efficiency vs. Output Current,

VOUT = 3.0V VOUT = 3.3V

Figure 5. Output Voltage vs. Temperature; Figure 6. Output Voltage vs. Battery Voltage;

VOUT = 3.3V, IOUT = 10mA VOUT = 3.3V, IOUT = 10mA

Figure 7. Startup Voltage vs. Output Current; Figure 8. Output Current vs. Battery Voltage;

VOUT = 3.3V, 3% Tolerance

100

1 10 100 1000

O utput Curr ent (mA)

Eff iciency (%) .

0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5

B at tery Volt age ( V)

O utput Curr ent (m A ) .

VIN = 2.4V

VIN = 1.5V

VIN = 1.0V

0.5

1.5

2.5

3.5

00.511.522.533.5

B atter y Voltage ( V)

Output V oltage ( V ) .

3.24

3.26

3.28

3.3

3.32

3.34

3.36

-50-25 0 25 50 75100

T emperature (° C)

Output V oltage ( V ) .

0.6

0.7

0.8

0.9

1.1

1.2

1.3

1.4

1.5

1.6

0.1 1 10 100

O utput Curr ent (mA)

S tar tup Voltage ( V ) .

3.3V

100

200

300

400

500

600

700

800

900

1000

0.5 1 1.5 2 2.5 3

Battery Voltage (V )

O utput Curr ent (m A ) .

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 6 - 18

AS1322

Datasheet - Typical Operating Characteristics

Figure 9. Output Current vs. Battery Voltage; Figure 10.

No Load Battery Current vs. V

BATT

VOUT = 5.0V, 3% ToleranceVOUT = 3.3V, TAMB = 25ºC

Figure 11. SW Pin Antiringing Operation Figure 12.

SW Pin Fixed Frequency Continuous Current

VIN

= 1.3V, V

OUT

= 3.3V, L = 10µH, C = 10µF, I

OUT

= 5mA

VIN

= 1.3V, V

OUT

= 3.3V, L = 10µH, C = 10µF, I

OUT

= 100mA

Figure 13. VOUT Transient Response. Figure 14. Fixed Frequency vs. Powersave Operation

VIN = 1.3V, VOUT = 3.3V, L = 10µH, C = 10µF VIN = 1.3V, VOUT = 3.3V, L = 10µH, C = 10µF

Parts used for measurements: 10µH (MOS6020-103ML) Inductor, 10µF (GRM31CR70J106KA01L) CIN and COUT

100

1000

1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3

Batt er y Voltage ( V)

Batt er y Cur r ent (µ A ) .

100

200

300

400

500

600

700

800

900

0.511.522.533.54

Battery Voltage (V )

O utput Curr ent (m A ) .

100ns/Div

VSW

0V 1V/Div

100ns/Div

VSW

0V 1V/Div

100µs/Div

VOUT(AC)

IOUT

40mA 100mA 100mV/Div

10ms/Div

VOUT(AC)

IOUT

1mA 60mA 100mV/Div

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 7 - 18

AS1322

Datasheet - Detailed Description

8 Detailed Description

The AS1322/AS1322B can operate from a single-cell input voltage (VIN) below 1V, and feature fixed frequency (1.2MHz) and current mode

PWM control for exceptional line- and load-regulation. With low RDS(ON) and gate charge internal NMOS and PMOS switches, the devices

maintain high-efficiency from light to heavy loads.

Modern portable devices frequently spend extended time in low-power or standby modes, switching to high power-drain only when certain

functions are enabled. The AS1322A and the AS1322B are ideal for portable devices since they maintain high-power conversion efficiency over

a wide output power range, thus increasing battery life in these types of devices.

In addition to high-efficiency at moderate and heavy loads, the AS1322A includes an automatic powersave mode that improves efficiency of the

power converter at light loads. The powersave mode is initiated if the output load current falls below a factory programmed threshold (see Figure

3 on page 5).

Note: The AS1322B does not support powersave mode and provides continuous operation at light loads, eliminating low-frequency VOUT

ripple at the expense of light load efficiency.

Figure 15. AS1322 - Bl ock Diagram

8.1 Low-Voltage Start-Up

The AS1322 requires VIN of only 0.85V (typ) or higher to start up. The low-voltage start-up circuitry controls the internal NMOS switch up to a

maximum peak inductor current of 850mA (typ), with 1.5ms (approx.) off-time during start-up, allowing the devices to start up into an output load.

With a VOUT > 2.3V, the start-up circuitry is disabled and normal fixed-frequency PWM operation is initiated. In this mode, the AS1322 operates

independent of VIN, allowing extended operating time as the battery can drop to several tenths of a volt without affecting output regulation. The

limiting factor for the application is the ability of the battery to supply sufficient energy to the output.

AS1322

–

Start Up

OSC

PWM

Control

A/B

MUX

Slope

Compensator

1.2MHz

Ramp

Generator

–

Powersave

Operation

Control

–

Shutdown

Control

PWM

Comp

–

1.23V

Ref

Sync Drive

Control

BVOUT

Good

2.3V

gm Error

Amp

Shutdown

Powersave

0.35Ω0.45Ω

640kΩ 1%

1.02MΩ

CFF*

COUT

4.7µF

3.3V

Output

CIN

1µF

1.5V

Single Cell

* Optional

Current

Sense

80kΩCP2

2.5pFCC

150pF

GND

SHDNN

VIN 5

VOUT

4.7µH

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 8 - 18

AS1322

Datasheet - Detailed Description

8.2 Low-Noise Fixed-Frequency Operation

8.2.1 Oscillator

The AS1322 switching frequency is internally fixed at 1.2MHz allowing the use of very small external components.

8.2.2 Error Amplifier

The integrated error amplifier is an internally compensated trans-conductance (gm) type (current output). The internal 1.23V reference voltage is

compared to the voltage at pin FB to generate an error signal at the output of the error amplifier. A voltage divider from VOUT to GND programs

the output voltage from 2.5 to 5V via pin FB as: VOUT = 1.23V(1 + (R1/R2)) (EQ 1)

8.2.3 Current Sensing

A signal representing the internal NMOS-switch current is summed with the slope compensator. The summed signal is compared to the error

amplifier output to provide a peak current control command for the PWM. Peak switch current is limited to approximately 850mA independent of

VIN or VOUT.

8.2.4 Zero Current Comparator

The zero current comparator monitors the inductor current to the output and shuts off the PMOS synchronous rectifier once this curren t d r ops t o

20mA (approx.). This prevents the inductor current from reversing polarity and results in improved converter efficiency at light loads.

8.2.5 Anti-Ringing Control

Anti-ringing control circuitry prevents high-frequency ringing on pin SW as the inductor current approaches zero. This is accomplished by

damping the resonant circuit formed by the inductor and the capacitance on pin SW (CSW).

8.3 Powersave Operation (AS1322A)

In light load conditions, the integrated powersave feature removes power from all circuitry not required to monitor VOUT. When VOUT has

dropped approximately 1% from nominal, the AS1322A powers up and begins normal PWM operation.

COUT (see Figure 15 on page 7) recharges, causing the AS1322A to re-enter powersave mode as long as the output load remains below the

powersave threshold. The frequency of this intermittent PWM is proportional to load current; i.e., as the load current drops further below the

powersave threshold, the AS1322A turns on less frequently . When the load current increases above the powersave threshold, the AS1322A will

resume continuous, seamless PWM operation.

Notes:

1. An optional capacitor (CFF) between pins VOUT and FB in some applications can reduce VOUTp-p ripple and input quiescent current

during powersave mode. Typical values for CFF range from 15 to 220pF.

2. In powersave mode the AS1322A draws only 30µA from the output capacitor(s), greatly improving converter efficiency.

8.4 Shutdown

When pin SHDNN is low the AS1322 is switched off and <1µA current is drawn from battery; when pin SHDNN is high the device is switched on.

If SHDNN is driven from a logic-level output, the logic high-level (on) should be referenced to VOUT to avoid intermittently switching the device

on.

Note: If pin SHDNN is not used, it should be connected directly to pin OUT. VOUT is held at approximately VIN - 0.6V during shutdown.

In shutdown the battery input is connected to the output through the inductor and the internal synchronous rectifier P-FET. Due to the body diode

of the internal synchronous rectifier PFET, VOUT is held at approximately VIN - 0.6V during shutdown. This allows the input battery to provide

backup power for devices such as an idle microcontroller, memory, or real-time-clock, without the usual diode forward drop. In this way a

separate backup battery is not needed.

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 9 - 18

AS1322

Datasheet - Application Informatio n

9 Application Information

The AS1322 is perfectly suited for LED matrix displays, bar-graph displays, instrument-panel meters, dot matrix displays, set-top boxes, white

goods, professional audio equipment, medical equipment, industrial controllers to name a few applications.

Along with Figure 1 on page 1, Figures 16-19 depict a few of the many applications for which the AS1322 converters are perfectly suited.

Figure 16. Single AA Cell to 3.3V Synchronous Boost Converter with Load Disconnect in Shutdown

Figure 17. Single Lithium Cell to 5V, 250mA

AS1322 C2

4.7µF

604kΩ

Off

4.7µH

Battery C1

4.7µF

510kΩ

VOUT

3.3V, 160mA

1.02MΩ

GND

SHDNN

VIN

VOUT

AS1322 C2

4.7µF

332kΩ 1%

1.02MΩ 1%

Off

4.7µH

Lithium

Battery C1

4.7µF

100pF

100nF

2Ω

Optional

Snubber

GND

SHDNN

VIN

VOUT

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 10 - 18

AS1322

Datasheet - Application Informatio n

Figure 18. Single AA Cell to ±3V Synchronous Boost Converter

Figure 19. Single AA Cell to 2.5V Synchronous Boost Converter

AS1322

750kΩ

1.02MΩ

Off

4.7µH

Battery C1

4.7µF

1µF

VOUT2

-3V, 10mA

VOUT1

3V, 90mA

4.7µF

10µF

GND

SHDNN

VIN

VOUT

AS1322 C2

10µF

1.02MΩ

Off

4.7µH

Battery C1

10µF

VOUT

2.5V, 230mA

GND

SHDNN

VIN

VOUT

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 11 - 18

AS1322

Datasheet - Application Informatio n

9.1 Output Voltage Ripple

The AS1322 is designed to work at high efficiency. In order to reduce the output ripple the following improvements are recommended:

! Use a higher output capacitor, up to 44µF and a higher input capacitor (22µF).

! Use smaller values for the resistor divider. R1 should be about 300kΩ. To avoid a high leakage current from pin VOUT through the resistor

divider to GND, R1 should not be less than 100kΩ.

! To reduce the output ripple it’s also possible to speed up the feedback loop. To achieve this, place a 22pF (C4 in Figure 20) capacitor in

parallel to R1. Via C4 the fast transients are shorted to the FB pin and the feedback loop is even faster. A 1MΩ resistor for R1 slows down

the FB loop.

! Due to noise and to their non linear behavior, the use of potentiometers is not recommended.

Figure 20. AS1322 - Typical Application for lower Output Voltage Ripple

Note: For correct measurements of the output ripple connect the oscilloscope probe as close as possible to the positive plate of the COUT

and connect the GND of the oscilloscope probe to the negative plate of the COUT. This will reduce the inductive coupling and will

deliver a more accurate measurement result.

The output ripple is getting higher as VIN is getting closer to VOUT. Figure 21 shows that the above mentioned improvements reduce the output

voltage ripple. If VIN is higher than VOUT the AS1322 stops switch ing and VIN is connected to VOUT via the inductor and the internal P-FET.

Figure 21. Output Voltage Ripple vs. Input Voltage; VOUT = 2.8V, IOUT = 0.8mA

AS1322 C2

22µF

196kΩ

250kΩ

Off

4.7µH

2xAA Battery

22µF

VOUT = 2.8V

GND

SHDNN

VOUT C3

22µF

22pF

VIN

100

125

0.5 1 1.5 2 2.5 3 3.5

Input Volt age ( V)

Output Voltage Ripple ( m Vpp)

Cout = 44µF

Cout = 66µF

Cout = 44µF + C4 = 22pF

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 12 - 18

AS1322

Datasheet - Application Informatio n

9.2 External Component Selection

9.2.1 Inductor Selection

The fast switching frequency (1.2MHz) of the AS1322 allows for the use of small surface mount or chip inductor for the external inductor (see

Figure 15 on page 7).

The required minimum values for the external inductor are:

! 3.3µH for applications ≤ 3.6V

! 4.7µH for applications > 3.6V

Larger inductor values allow greater output current capability by reducing the inductor ripple current. Increasing the inductance above 10µH will

increase size while providing negligible improvement in output current capability.

The approximate output current capability of the AS1322 versus inductor value is given in:

Where:

η is the estimated efficiency;

IP is the peak current limit value (0.6A);

VIN is the input voltage;

D is the steady-state duty ratio = (VOUT - VIN)/VOUT;

f is the switching frequency (1.2MHz typ);

L is the inductor value.

The inductor current ripple is typically set for 20 to 40% of the maximum inductor current (IP). High-frequency ferrite core inductor materials

reduce frequency dependent power losses compared to less expensive powdered iron types, which result in improved converter efficiency.

The inductor should have low ESR to reduce the I2R power losses, and must be able to handle the peak inductor current without saturating.

Molded chokes and some chip inductors normally do not have enough core to support the peak inductor currents of the AS1322 (850mA typ). To

minimize radiated noise, use a toroid, pot core, or shielded bobbin inductor.

Table 5. Recommended Inductors

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

MOS6020-103ML 10µH 93mΩ1A 6.8x6.0x2.4mm Coilcraft

www.coilcraft.com

MOS6020-472ML 4.7µH 50mΩ1.5A 6.8x6.0x2.4mm

MOS6020-332ML 3.3µH 46mΩ1.8A 6.8x6.0x2.4mm

CDRH4D18-100 10µH 200mΩ0.61A 6.9x5.0x2.0mm Sumida

www.sumida.com

CDRH4D18-6R8 6.8µH 200mΩ0.76A 6.9x5.0x2.0mm

CR43-6R8 6.8µH 131.2mΩ0.95A 4.8x4.3x3.5mm

CDRH4D18-4R7 4.7µH 162mΩ0.84A 6.9x5.0x2.0mm

(EQ 2)

IOUT MAX()ηIPVIN D⋅

fL2⋅⋅

------------------

–

⎝⎠

⎛⎞

1D–()⋅⋅=

www.austriamicrosystems.com/DC-DC_Step-Up/AS1322 Revision 1.09 13 - 18

AS1322

Datasheet - Application Informatio n

Figure 22. Efficiency Comparison of Different Inductors, VIN = 1.5V, VOUT = 3.3V

9.2.2 Output Capacitor Selection

Low ESR capacitors should be used to minimize VOUT ripple. Multi-layer ceramic capacitors are recommended since they have extremely low

ESR and are available in small footprints. A 2.2 to 10µF output capacitor is sufficient for most applications. Larger values up to 22µF may be

used to obtain extremely low output voltage ripple and improve transient response.

An additional phase lead capacitor may be required with output capacitors larger than 10µF to maintain acceptable phase margin. X5R and X7R

dielectric materials are recommended due to their ability to maintain capacitance over wide voltage and temperature ranges.

Input Capacitor Selection. Low ESR input capacitors reduce input switching noise and reduce the peak current drawn from the battery.

Ceramic capacitors are recommended for input decoupling and should be located as close to the device as is practical. A 4.7µF input capacitor

is sufficient for most applications. Larger values may be used without limitations.

Diode Selection. A Schottky diode should be used to carry the output current for the time it takes the PMOS synchronous rectifier to switch

on. For VOUT < 4.5V a Schottky diode is optional, although using one will increase device efficiency by 2 to 3%.

Note: Do not use ordinary rectifier diodes, since the slow recovery times will compromise efficiency .

Table 6. Recommended Output Capacitor

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

JMK212BJ226MG-T 22µF ±20% X5R 6.3V 2x1.3x1.3mm Taiyo Yuden

www.t-yuden.com

Table 7. Recommended Input Capacitor

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

GRM31CR70J106KA01L 10µF ±10% X7R 6.3V 3.2x1.6x1.6mm Murata

www.murata.com

10010

O utput Cur r ent ( mA)

Ef f iciency (%)

10uH - Coilcr af t (MOS 60 20-103ML)

10uH - Su mida(CDRH4D18-100)

6.8uH - S um ida(CDRH4D18-6R8)

6.8uH - S um ida(CR43-6R8)

4.7uH - Coilcr af t(MOS 60 20-472ML)

4.7 uH - S um ida(CDRH4D18-4R7)

3.3 uH - Coilcr af t(MOS 6 020-332ML)

Si 8

0.1 1 10

Output Current (mA)

Ef ficiency (%)

10uH - Coilcr af t (MOS 6020-103ML)

10u H - Sum ida (CDRH4D1 8-1 00)

6.8uH - Sumida (CDRH4D18 -6 R8)

6.8uH - S um ida(CR43-6R8)

4.7uH - Coilcr af t(MOS 6020-472ML)

4.7 uH - Sum ida(CDRH4 D18- 4R7)

3.3 uH - Coilcr af t(MOS 6020 -332ML)

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AS1322

Datasheet - Application Informatio n

9.3 PCB Layout Guidelines

The high-speed operation of the AS1322 requires proper layout for optimum performance. Figure 23 shows the recom men ded component

layout.

! A large ground pin copper area will help to lower the device temperature.

! A multi-layer board with a separate ground plane is recommended.

! T races carrying large currents should be direct.

! T race area at pin FB should be as small as is practical.

! The lead-length to the battery should be as short as is practical.

Figure 23. Recommended Single-Layer Component Placement

1AS1322

Optional

SHDNN

VIN

VOUT

GND

VOUT

VIN

SHDNN

R1COUT

CIN

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AS1322

Datasheet - Package Drawings and Markings

10 Package Drawings and Markings

The device is available in a 6-pin TSOT-23 package.

Figure 24. 6-pi n TSOT-23 Package

34A

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AS1322

Datasheet - Package Drawings and Markings

Notes:

1. Dimensioning and tolerancing conform to ASME Y14.5M - 1994.

2. Dimensions are in millimeters.

3. Dimension D does not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, and gate burrs shall not exceed 0.15mm

per end. Dimension E1 does not include interlead flash or protrusion. Interlead flash or protrusion shall not exceed 0.15mm per side.

Dimensions D and E1 are determined at datum H.

4. The package top can be smaller than the package bottom. Dimensions D and E1 are determined at the outermost extremes of the plas-

tic body exclusive of mold flash, tie bar burrs, gate burrs, and interlead flash, but include any mistmatches between the top of the pack-

age body and the bottom. D and E1 are determined at datum H.

5. Datums A and B are to be determined at datum H.

6. These dimensions apply to the flat section of the lead between 0.08 and 0.15mm from the lead tip.

7. Dimension b does not include dambar protrusion. Allowable dambar protrusion shall be 0.08mm total in excess of the b dimension at

the maximum material condition. The dambar cannot be located on the lower radius of the foot. Minimum space between the protru-

sion and an adjacent lead shall not be less than 0.77mm.

Tolerances of Form and Position

aaa 0.15 1,2

bbb 0.25 1,2

ccc 0.10 1,2

ddd 0.20 1,2

Symbol Min Typ Max Notes

A1.00

A1 0.01 0.05 0.10

A2 0.84 0.87 0.90

b 0.30 0.45 6,7

b1 0.31 0.35 0.39 6,7

c 0.12 0.15 0.20 6

c1 0.08 0.13 0.16 6

D 2.90BSC 3,4

E 2.80BSC 3,4

E1 1.60BSC 3,4

Symbol Min Typ Max Notes

e 0.95BSC

e1 1.90BSC

L 0.30 0.40 0.50

L1 0.60REF

L2 0.25BSC

R0.10

R1 0.10 0.25

θ0º 4º 8º

θ14º 10º 12º

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AS1322

Datasheet - Ordering Information

11 Ordering Information

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

Note: All products are RoHS compliant.

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

Technical Support is found at http://www.austriamicrosystems.com/Technical-Support

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

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

Design the AS1322 online at http://www.austriamicrosystems.com/analogbench

analogbench is a powerful design and simulation support tool that operates in on-line and off-line mode to evaluate performance and

generate application-specific bill-of-materials for austriamicrosystems' power management devices.

Table 8. Ordering Information

Ordering Code Marking Description Delivery Form Package

AS1322A-BTTT ASKQ Low Voltage, Micropower, DC-DC Step-Up Converter with

Automatic Powersave Operation Tape and Reel 6-pin TSOT-23

AS1322B-BTTT ASKZ Low V oltage, Micropower, DC-DC Step-Up Converter with

Continuous Switching Tape and Reel 6-pin TSOT-23

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AS1322

Datasheet

Copyrights

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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, statutory , implied, or by description regarding the information set forth herein or regarding

the freedom of the described devices from patent infringement. austriamicrosystems 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 applications, 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, austriamicrosystems AG shall not

be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use,

interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing,

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austriamicrosystems AG rendering of technical or other services.

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