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DS-1610P-04

AIC1610/AIC1611

High Efficiency Synchronous Step-Up DC/DC

Converter

Analog Integrations Corporation Si-Soft Research Center

DS-1610P-04 042806

FEATURES

High Efficiency (93% when V IN =2.4V, V OUT =3.3V, I OUT =200mA)

Output Current up to 500mA. (AIC1610 at V IN =2.4V and V OUT =3.3V)

20μA Quiescent Supply Current.

Power-Saving Shutdown Mode (0.1μA typical). Internal Synchronous Rectifier (No External Di-ode Required).

On-Chip Low Battery Detector. Low Battery Hysteresis

Space-Saving Package: MSOP-8

APPLICATIONS

Palmtop & Notebook Computers. . with 1 to 3-Cell of NiMH/NiCd Batteries.

PDAs

Wireless Phones Pocket Organizers Digital Cameras.

Hand-Held Devices

DESCRIPTION The AIC1610/AIC1611 are high efficiency step up DC-DC converters. The start-up volt-age is as low as 0.8V with operating voltage down to 0.7V. Simply consuming 20μA of qui-escent current. These devices offer a built-in synchronous rectifier that reduces size and cost by eliminating the need for an external Schottky diode and improves overall effi-ciency by minimizing losses.

The switching frequency can range up to 500KHz depending on the load and input volt-age. The output voltage can be easily set by two external resistors from 1.8V to 5.5V, connecting FB to OUT to get 3.3V, or con-necting to GND to get 5.0V. The peak current of the internal switch is fixed at 1.0A (AIC1610) or 0.65A (AIC1611) for design flexibility.

TYPICAL APPLICATION CIRCUIT

Low-battery Detect Out

ORDERING INFORMATION

PIN CONFIGURATION

TOP VIEW

GND

OUT

LBI

LBO

REF

SHDN

Example: AIC1610COTR

In MSOP-8 Package & Taping &

Reel Packing Type

AIC1610POTR

In MSOP-8 Lead Free Package &

Taping & Reel Packing Type

ABSOLUTE MAXIMUM RATINGS

Supply Voltage (OUT to GND) 8.0V

Switch Voltage (LX to GND) V OUT+ 0.3V , LBO to GND 6.0V LBI, REF, FB, to GND V OUT+0.3V

Switch Current (LX) -1.5A to +1.5A

Output Current (OUT) -1.5A to +1.5A

Operating Temperature Range -40°C ~ +85°C

Maximum Junction Temperature 125°C

Storage Temperature Range -65°C ~150°C

Lead Temperature (Soldering 10 Sec.) 260°C

Thermal Resistance Junction to Case MSOP-8 75°C/W

Thermal Resistance Junction to Ambient MSOP-8 180°C/W

Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.

Refer to Typical Application Circuit.

SHDN

(Assume no ambient airflow, no heatsink)

TEST CIRCUIT

ELECTRICAL CHARACTERISTICS(V IN=2.0V, V OUT=3.3V, FB=V OUT, T A=25°C, unless otherwise specified.) (Note1)

ELECTRICAL CHARACTERISTICS(Continued)

Note 1: Specifications are production tested at T A=25°C. Specifications over the -40°C to 85°C operating tem-perature range are assured by design, characterization and correlation with Statistical Quality Controls (SQC).

Note 2: Start-up voltage operation is guaranteed without the addition of an external Schottky diode between the input and output.

Note 3: Steady-state output current indicates that the device maintains output voltage regulation under load.

Note 4:Device is bootstrapped (power to the IC comes from OUT). This correlates directly with the actual bat-tery supply.

TYPICAL PERFORMANCE CHARACTERISTICS I n p u t B a t t e r y C u r r e n t (μA )

Input battery voltage (V)

Fig. 1 No-Load Battery Current vs. Input Battery

0.0

0.5 1.0 1.5 2.0

2.5

3.0

3.5

020

406080100120140160

S h u t d o w n C u r r e n t C u r r e n t (μA )

Supply Voltage (V)

Fig. 2 Shutdown Current vs. Supply Voltage

1.0 1.5

2.0 2.5

3.0 3.5

4.0

4.5

5.0 5.5

0.0

0.1

0.2

0.3

0.4

0.5

Fig. 3 Start-Up Voltage vs. Output Current

S t a r t -U p V o l t a g e (V )

0.00.2

0.40.60.81.01.21.41.6

1.8Output Current (mA)

Fig. 4 Turning Point between CCM & DCM

C C M /

D C M B o u n d a r y O u t p u t C u r r e n t

(m A )

Input Voltage (V)

0.5

1.0 1.5

2.0 2.5

3.0

3.5

4.0

4.5

5.0

100150200250300350400

Fig. 5 Efficiency vs. Load Current (ref. to Fig.33)

E f f i c i e n c y (%)

0102030405060708090100

Output Current (mA)

Fig. 6 Ripple Voltage (ref. to Fig.33)

R i p p l e V o l t a g e (m V )

Output Current (mA)

100

150

200

250

300

350

400

450 500

550600650

406080100120140160180

200220

TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

Fig. 7 Ripple Voltage (ref. to Fig.33)

R i p p l e V o l t a g e (m V )

Output Current (mA)

100

200

300

400

500

600

700800

120

160

200

240

Fig. 8 Efficiency vs. Load Current (ref. to Fig.33)

E f f i c i e n c y (%)

Output Current (mA)

0.01

0.1

110

100

1000

20304050607080

90100

Fig. 9 Ripple Voltage (ref. to Fig.33)

R i p p l e V o l t a g e (m V )

Output Current (mA) 0

100

150

200

250

300

350

400

450

500550

406080100

120140

160

Fig. 10 Ripple Voltage (ref. to Fig.33)

R i p p l e V o l t a g e (m V )

Output Current (mA)

100

200

300

400

500600

100

120

Fig. 11

Efficiency vs. Load Current (ref. to Fig.32)

(V ) E f f i c i e n c y (%)

Output Current (mA)

0.01

0.1

100

1000

10 20 30 40 50 60 70 80 90 100

Fig. 12 Ripple Voltage (ref. to Fig.32)

R i p p l e V o l

t a g e (m V )

Output Current (mA)

100

150

200

250

300

350

400

450

500550600

020

406080100120140160180200220

240260

TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

Fig. 13 Ripple Voltage (ref. to Fig.32)

R i p p l e V o l t a g e (m V )

Output Current (mA)

100

150

200

250

300

350

400

450

500

550

406080

Fig. 14 Efficiency vs. Load Current (ref. to Fig.32)

E f f i c i e n c y (%)

Output Current (mA)

010

2030405060708090100

Fig. 15 Ripple Voltage (ref. to Fig.32)

R i p p l e V o l t a g e (m V )

Output Current (mA)

0 50

100

150

200

250300

350

400

450

500

100

120

140

Fig. 16 Ripple Voltage (ref. to Fig.32)

R i p p l e V o l t a g e (m

V )

Output Current (mA)

100

150

200

250

300

350

400

450500

2030405060708090100110120

Fig. 17 Reference Voltage vs. Temperature

R e f e r e n c e V o l t a g e (V )

Temperature (°C)

-40

-20

1.20

1.21

1.22

1.23

1.24

1.25

1.26

Fig. 18

Switch Resistance vs. Temperature

R e s i s t a n c e (?)

Temperature (°C)

-60

-40

-20

020

80100

0.00

0.05

0.100.150.200.250.300.350.40

0.450.50

TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

Fig. 19 Maximum Output Current vs. Input Voltage

M a x i m u m O u t p u t C u r r e n t (m A )

1.0

1.2

1.4

1.6

1.8

2.0 2.2

2.4

2.6

2.8

3.0

100200300400500600700800

Input Voltage (V)

Fig. 20 Maximum Output Current vs. Input Voltage

M a x i m u m O u t

p u t C u r r e n t (m A )

1.0

1.5

2.0

2.5

3.0

3.5

4.0 4.5

100200300400500600700800900

Fig. 21 Inductor Current vs. Output Voltage

I L I M (A )

Output Voltage (V)

2.0

2.5

3.0

3.5

4.0

4.5

5.0

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Supply Voltage (V)

Fig. 22 Switching Frequency vs. Supply Voltage

S w i t c h i n g

F r e q u e n c y f o s c (K H z )

1.0

1.5

2.0

2.5

3.0

3.5

4.0 4.5

020406080100120140160

S w i t c h i n g F r e q u e n c y F o s c (K H z )

Output Current (mA)

100

1000

0 20 40 60

80 100120140160180200220

Fig. 23 Switching Frequency vs. Output Current

V IN =2.4V V OUT =3.3V

Fig. 24 LX Switching Waveform

TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

V IN =2.4V V OUT =3.3V Loading=200mA

LX Pin Waveform

Inductor Current

V OUT AC Couple

Fig. 25 Heavy Load Waveform

Loading: 1mA ? 200mA

V IN =2.4V V OUT =3.3V

V OUT : AC Couple

Fig. 26 Load Transient Response

V IN =2.0V~3.0V

V OUT =3.3V, I OUT =100mA

V OUT

Fig. 27 Line Transient Response

V IN

Fig. 28 Exiting Shutdown

V OUT

V SHDN

V OUT =3.3V C IN =C OUT =47μF

Fig. 29 Exiting Shutdown

V SHDN

V OUT

V OUT =3.3V C IN =C OUT =100μF

Fig. 30 Exiting Shutdown

V SHDN

V OUT

V OUT =5.0V C IN =C OUT =47μF

TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

Fig. 31 Exiting Shutdown

V OUT

V SHDN

V OUT =5.0V C IN =C OUT =100μF

BLOCK DIAGRAM

μF μF

VIN

OUT

PIN DESCRIPTIONS

PIN 1: FB- Connecting to OUT to get +3.3V

output, connecting to GND to get

+5.0V output, or using a resistor

network to set the output voltage

from +1.8V to +5.5V.

PIN 2: LBI- Low-battery comparator input. In-

ternally set at +1.23V to trip.

PIN 3: LBO- Open-drain low battery comparator

output. Output is low when V LBI is

<1.23V. LBO is high impedance

during shutdown. PIN 4: REF- 1.23V reference voltage. Bypass

with a 0.1μF capacitor.

PIN 5: SHDN- Shutdown input. High=operating,

low=shutdown.

PIN 6: GND- Ground

PIN 7: LX- N-channel and P-channel power

MOSFET drain.

PIN 8: OUT- Power output. OUT provides boot-

strap power to the IC.

Overview

lly smaller inductor space-sensitive applications.

PFM Control Scheme

It is governed by a pair of one-shots that set a minimum

-time (4μS).

ithout an additional external Schottky diode. Thus, the conversion efficiency can e as high as 93%.

ation (<10mV). A bypass capacitor of 0.1μF is required for proper operation and good per-

APPLICATION INFORMATION

AIC1610/AIC1611 series are high efficiency, step-up DC-DC converters, designed to feature a built-in synchronous rectifier, which reduces size and cost by eliminating the need for an external Schottky di-ode. The start-up voltage of AIC1610/AIC1611 is as low as 0.8V and it operates with an input voltage down to 0.7V. Quiescent supply current is only 20μA. The internal P-MOSFET on-resistance is typically 0.3? to improve overall efficiency by minimizing AC losses. The output voltage can be easily set by two external resistors from 1.8V to 5.5V, connecting FB to OUT to get 3.3V, or connecting to GND to get 5.0V. The peak current of the internal switch is fixed at 1.0A (AIC1610) or 0.65A (AIC1611) for design flexibility. The current limit of AIC1610 and AIC1611 are 1.0A and 0.65A respectively. The lower current limit allows the use of a physica

The key feature of the AIC1610 series is a unique minimum-off-time, constant-on-time, current-limited, pulse-frequency-modulation (PFM) control scheme (see BLOCK DIAGRAM) with the ultra-low quies-cent current. The peak current of the internal N-MOSFET power switch can be fixed at 1.0A (AIC1610) or 0.65A (AIC1611). The switch frequency depends on either loading condition or input voltage, and can range up to 500KHz.

off-time (1μS) and a maximum on

Synchronous Rectification

Using the internal synchronous rectifier eliminates the need for an external Schottky diode. Therefore, the cost and board space are reduced. During the cycle of off-time, P-MOSFET turns on and shunts N-MOSFET. Due to the low turn-on resistance of MOSFET, synchronous rectifier significantly im-proves efficiency w

Reference Voltage

The reference voltage (REF) is nominally 1.23V for excellent T.C. performance. In addition, REF pin can source up to 100μA to external circuit with good load regul

formance

Shutdown

The whole circuit is shutdown when SHDN V is low. At shutdown mode, the current can flow from battery to output due to body diode of the P-MOSFET. V OUT falls to approximately Vin-0.6V and LX remains high impedance. The capacitance and load at OUT de-termine the rate at which V OUT decays. Shutdown can be pulled as high as 6V. Regardless of the volt-. Vout can be calculated om 1.8V to is 240K ?.

BO ( an open-drain out-

1. age at OUT.

Selecting the Output Voltage

V OUT can be simply set to 3.3V/5.0V by connecting

FB pin to OUT/GND due to the use of internal resis-tor divider in the IC (Fig.32 and Fig.33). In order to adjust output voltage, a resistor divider is connected to V OUT , FB, GND (Fig.34)by the following equation:

R5=R6 [(V OUT / V REF )-1].....................................(1) Where V REF =1.23V and V OUT ranging fr 5.5V. The recommended R6Low-Battery Detection

AIC1610 series contains an on-chip comparator with 50mV internal hysteresis (REF, REF+50mV) for low battery detection. If the voltage at LBI falls below the internal reference voltage. L put) sinks current to GND.

Component Selection Inductor Selection

An inductor value of 22μH performs well in most applications. The AIC1610 series also work with inductors in the 10μH to 47μH range. An induc-tor with higher peak inductor current tends a higher output voltage ripple (I PEAK output filter capacitor ESR). The inductor’s DC resistance significantly affects efficiency. We can calculate the maximum output current as follows:

η????

??????×?L 2t I V I OFF LIM OUT

)MAX (OUT ………?

????=

V V V IN OUT IN ……………………………………………(2) whe imum output current in amp lly 0.9) μS LIM 2. igher or in applica-3. the IC’s

re I OUT(MAX)=max s

V IN =input voltage L=inductor value in μH =efficiency (typica t OFF =LX switch’ off-time in I =1.0A or 0.65A

Capacitor Selection

The output ripple voltage relates with the peak inductor current and the output capacitor ESR. Besides output ripple voltage, the output ripple current also needs to be concerned. A filter ca-pacitor with low ESR is helpful to the efficiency and steady state output current of AIC1610 se-ries. Therefore NIPPON tantalum capacitor MCM series with 100μF/6V is recommended. A smaller capacitor (down to 47 F with h ESR) is acceptable for light loads tions that can tolerate higher output ripple. PCB Layout and Grounding

Since AIC1610’s switching frequency can range up to 500kHz, it makes AIC1610 become very sensitive. So careful printed circuit layout is im-portant for minimizing ground bounce and noise. IC’s OUT pin should be as clear as possible. And the GND pin should be placed close to the ground plane. Keep the IC’s GND pin and the ground leads of the input and output filter ca-pacitors less than 0.2in (5mm) apart. In addition, keep all connection to the FB and LX pins as short as possible. In particular, when using ex-ternal feedback resistors, locate them as close to the FB as possible. To maximize output pow-er and efficiency and minimize output ripple voltage, use a ground plane and solder

GND directly to the ground plane. Fig. 35 to 37 Two or three parallel output capacitors can sig-ge of

.39 to Fig.46 are the performances of Fig. 38.

are the recommended layout diagrams.

Ripple Voltage Reduction

AIC1610/11. The addition of an extra input ca-pacitor results in a stable output voltage. Fig.38 shows the application circuit with the above fea-tures. Fig nificantly improve output ripple volta

APPLICATION EXAMPLES VOUT

L: TDK SLF7045T -22OM R90

C1, C3: NIPPON T antalum Capacitor 6M CM 476M B2TER

VOUT

L: TDK SLF7045T-22OM R90

C1, C3: NIPPON T antalum Capacitor 6M CM 476M B2TER

Fig. 32 V OUT = 3.3V Application Circuit.

Fig. 33 V OUT = 5.0V Application Circuit.

C1, C3: NIPPON Tantalum Capacitor 6MCM476MB2TER V OUT =V REF *(1+R5/R6)

L: TDK SLF7045T-22OM R90

C1, C3: NIPPON T antalum Capacitor 6M CM 476MB2TER

Fig. 34 An Adjustable Output Application Circuit Fig. 35 Low Battery Detection for V IN < 1.23

APPLICATION EXAMPLES (Continued)

VOUT

L: TDK SLF7045T-22OM R90

C1, C3: NIPPON T antalum Capacitor 6M CM476M B2TER

V H=1.23(1+R1/R2+R1/R3)

V L=1.23[1+R1/R2?R1(V OUT?1.23)/1.23(R3+R4)]

Where V H is the upper trip level

V L is the lower trip level

Fig. 36 Adding External Hysteresis to Low Battery Detection

Fig. 37 Top layer Fig. 38 Bottom layer Fig. 39 Placement

APPLICATION EXAMPLES d) (Continue

V OUT R5=open, R6=0?; for V OUT =5.0V

V OUT =1.23(1+R5/R6); for adjustable output voltage

μF

L1: TDK SLF7045T-22OMR90

C1~C2, C6~8: NIPPON Tantalum Capacitor 6MCM107MCTER

Fig. 40 AIC1610/11 application circuit with small ripple voltage.

Fig. 41 Efficiency (ref. to Fig.40)

E f f i c i e n c y (%)

Output Current (mA) 0.01 0.1

100

1000

3035404550556065707580859095100

Fig. 42 Ripple Voltage (ref. to Fig.40)

R i p p l e V o l t a g e (m V )

Output Current (mA)

100

200

300

400

500

600700

APPLICATION EXAMPLES (Continued)

Fig. 43 Efficiency (ref. to Fig.40)

E f f i c i e n c y (%)

Output Current (mA) 60

0.01

0.1

1 10

100

1000

253035404550556065707580859095

Fig. 44 Ripple Voltage (ref. to Fig.40)

R i p p l e V o l t a g e (m V )

Output Current (mA)

100

200

300

400

500

Fig. 45 Efficiency (ref. to Fig.40)

E f f i c i e n c

y (%)

Output Current (mA) 0.01

0.1

100

1000

404550556065707580859095100

Fig. 46 Ripple Voltage (ref. to Fig.40)

R i p p l e V o l t a g e (m V )

Output Current (mA)

100

150

200

250

300

350

400

450

500550600

10152025303540

4550

Fig. 47 Efficiency (ref. to Fig.40)

E f f i c i e n

c y (%)

Output Current (mA) 0.01

0.1

100

1000

404550556065707580859095100

Fig. 48 Ripple Voltage (ref. to Fig.40)

R i p p l e V o l t a g e (m V )

Output Current (mA)

100

150

200

250

300

350400

PHYSICAL DIMENSION (unit: mm) MSOP-8

Note:

Information provided by AIC is believed to be accurate and reliable. However, we cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AIC product; nor for any infringement of patents or other rights of third parties that may result from its use. We reserve the right to change the circuitry and specifications without notice.

Life Support Policy: AIC does not authorize any AIC product for use in life support devices and/or systems. Life support devices or systems are devices or systems which, (I) are intended for surgical implant into the body or (ii) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user.

VIEW B

SECTION A-A

SEE VIEW B

Note:

1. Refer to JEDEC MO-187AA.

2. Dimension “D” does not include mold flash, protrusions or gate burrs. Mold flash, protrusion or gate burrs shall not exceed 6 mil per side.

3. Dimension “E” does not include inter-lead flash or protrusions. Inter-lead flash and protrusions shall not exceed 10 mil per side.

4. Controlling dimension is millimeter, converted inch dimensions are not necessarily exact.