Datasheet SP6641AEK-3.3, SP6641AEK-5.0, SP6641BEK-3.3, SP6641BEK-5.0 Datasheet (Sipex)

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Page 1

SP6641A/6641B

500mA Alkaline DC/DC Boost Regulator in SOT-23

■ Ultra Low Quiescent Current: 10µA

■ Wide Input Voltage Range: 0.9V to 4.5V

■ 90mA I

■ 500mA I

■ 100mA I

■ 500mA I

at 1.3V Input (SP6641A-3.3V)

OUT

at 2.6V Input (SP6641B-3.3V)

OUT

at 2.0V Input (SP6641A-5.0V)

OUT

at 3.3V Input (SP6641B-5.0V)

OUT

■ Fixed 3.3V or 5.0V Output Voltage

■ Up to 87% Efficiency

■ 0.3Ω NFET RDSon

■ Startup Voltage Guaranteed at 0.9V

■ 0.33A Inductor Current Limit (SP6641A)

■ 1A Inductor Current Limit (SP6641B)

■ Logic Shutdown Control

■ SOT-23-5 Package

APPLICATIONS

■ PDA's

■ DSC's

■ CD/MP3 Players

■ Pagers

■ Digital Cameras

■ Portable Handheld Medical Devices

Now Available in Lead Free Packaging

GND

OUT

SP6641

5 Pin SOT-23

BATT

SHDN

DESCRIPTION

The SP6641 is an ultra-low quiescent current, high efficiency, DC-DC boost converter designed for single and dual cell alkaline, or Li-ion battery applications found in PDA’s, MP3 players, and other handheld portable devices. The SP6641 features a 10µA quiescent current, a 0.3Ω N- channel charging switch, 0.9V input startup, and a 0.33A or 1.0A inductor current limiting feature. The SP6641 is offered in a 5 pin SOT-23 package and provides an extremely small power supply footprint optimized for portable applications. The SP6641 is preset to 3.3V and can be controlled by a 1nA active LOW shutdown pin.

SP6641A 3.3V & 5V: C1 = C2 = 22µF Ceramic, L1 = 22µH CDRH5D28,

SP6641B 3.3V & 5V: C1 = C2 = 100µF POSCAP, L1 = 10µH CDRH5D28,

GND

OUT

D1 = MBR0520, C3 = Open, R1 = Shorted.

D1 = ZHCS2000, C3 = 1µF Ceramic, R1 = 10Ω.

SP6641A

BATT

SHDN

Figure 1. Typical Application Schematic

Rev. 5/26/05,

*Patent Pending

0.9V to 4.5V V

BATT

SHDN

OUT

+3.3V or 5V

700 650 600 550 500 450 400 350

(mA)

300

OUT

250 200 150 100

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

(V)

SP6641B, 1.0A, 3.3V SP6641B, 1.0A, 5V SP6641A, 0.33A, 3.3V SP6641A, 0.33A, 5V

Figure 2. Maximum Load Current in Operation

Page 2

ABSOLUTE MAXIMUM RATINGS

These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability.

LX, V

LX Current.......................................................... 1.5A

Reverse V

Storage Temperature ........................ -65°C to 150°C

Operating Temperature..................... -40°C to +85°C

Lead Temperature (Soldering, 10 sec) .......... 300 °C

, SHDN, V

OUT

Current ................................... 220mA

BATT

to GND pin .......-0.3 to 6.0V

BATT

ELECTRICAL SPECIFICATIONS

= V

BATT

unless otherwise noted.

PARAMETER MIN TYP MAX UNITS CONDITIONS

Input Voltage Operating Range, 0.5 4.5 V after startup V

BATT

Startup Voltage, V

Output Voltage, V

Quiescent Current into V I

Q(OUT)

Quiescent Current into V I

Shutdown Current into V I

SHDN

Shutdown Current into V I

SHDN

Inductor Current Limit 280 330 380 mA (SP6641A)

Inductor Current Limit 850 1000 1150 mA (SP6641B)

Output Current (SP6641AEK-3.3) 90 mA V

Output Current (SP6641BEK-3.3) 200 mA V

Output Current (SP6641AEK-5.0) 100 mA V

Output Current (SP6641BEK-5.0) 275 mA V

Minimum Off-Time Constant 1.50 V*µsT K

OFF

NMOS Switch Resistance 0.3 0.75 Ω Inmos=100mA SHDN Input Voltage Vil 20 % % of V

SHDN Input Current 1 100 nA

SHDN

= 1.3V, I

= 0mA, -40°C <TA < +85°C, V

LOAD

BATT

OUT

3.16 3.30 3.44 V 3.3V V

4.80 5.00 5.20 V 5.0V V

,1015µAV

OUT

, 250 500 nA V

BATT

,1500 nA V

OUT

,20100 nA V

BATT

Vih 80 % % of V

= +3.3V or +5.0V preset, typical values at 27°C

OUT

0.85 0.90 V R

1.00 V R

190 mA V

500 mA V

175 mA V

500 mA V

LOAD LOAD

=3.5V, 3.3V V

OUT

=5.5V, 5.0V V

OUT

=3.5V, 3.3V V

OUT

=5.5V, 5.0V V

OUT SHDN

SHDN

=1.3V

BATT

=2.6V

BATT

=1.3V

BATT

=2.6V

BATT

=2.0V

BATT

=3.3V

BATT

=2.0V

BATT

=3.3V

BATT

≥ K

OFF

=3kΩ, TA =27°C =3kΩ,-40°C <TA < +85°C

preset

OUT

preset

OUT

preset

OUT

preset

OUT

preset

OUT

preset

OUT

=0V

/ (V

OUT

– VIN)

OFF

BATT BATT

Rev. 5/26/05,

*Patent Pending

Page 3

PIN DESCRIPTION

PIN NO. PIN NAME DESCRIPTION

1LXInductor switching node. Connect one terminal of the inductor to the

positive terminal of the battery. Connect the second terminal of the inductor to this pin. The inductor charging current flows into LX, through the internal charging N-channel FET, and out through the GND pin.

2 GND Ground pin. The internal regulator bias currents and the inductor

charging current flows out of this pin.

OUT

Output voltage sense pin, internal regulator voltage supply, and minimum off-time one shot input. Kelvin connect this pin to the positive terminal of the output capacitor, but for SP6641B, use 10Ω series resistor and 1µF bypass per Figure 1 schematic.

4 SHDN Shutdown. Tie this pin to V

ground to disable all circuitry inside the chip. In shutdown mode, the output voltage will float at a diode drop below the battery potential.

BATT

Battery voltage pin. The startup circuitry runs off of this pin. The regulating circuitry also uses this voltage to control the minimum offtime. T

BLOCK DIAGRAM

BATT

OFF

≥ K

OFF

/ (V

OUT

for normal operation. Tie this pin the

BATT

– VIN).

OUT

SHDN

Internal

BATT

OUT

BATT

Min.

SHDN

OUT

Ref

SHDN

Block

OUT

REFREADY

Internal Supply

OFF

REF

OUT(LOW)

BATT

SUGATE

OSC

CHARGE

DRIVER

NGATE

OUT

ITH

Internal Ground

ICHN

LOAD

GND

SP6641

Rev. 5/26/05,

*Patent Pending

Page 4

PERFORMANCE CHARACTERISTICS

)

Refer to the circuit in Figure 1, T

AMB

= +25°C

100

VIN = 3.0V

95 90

V V

= 2.6V

= 2.0V

V V

= 1.3V

= 1.0V

85 80 75

Efficiency (%)

70 65 60

0.1 1.0 10.0 100.0 1000.0

Iload (mA)

Figure 3. SP6641AEK - 3.3 Efficiency vs Load Current

3.400

3.380

3.360

3.340

VIN = 3.0V V

= 2.6V

= 2.0V

3.320

3.300

OUT

3.280

3.260

3.240

3.220

3.200 0

50 100 150

Iload (mA)

= 1.3V

= 1.0V

200 250

Figure 5. SP6641AEK - 3.3 Line/Load Rejection vs Load Current

100

VIN = 3.0V

= 2.6V

= 2.0V

= 1.3V

= 1.0V

85 80 75

Efficiency (%)

70 65 60

0.1 1.0 10.0 100.0 1000.0

Iload (mA)

Figure 4. SP6641BEK - 3.3 Efficiency vs Load Current

3.400

3.380

3.360

3.340

3.320

3.300

OUT

3.280

3.260

3.240

VIN = 3.0V V

= 2.6V

= 2.0V

V V

= 1.3V

= 1.0V

3.220

3.200 0 200 400 600 800

Iload (mA)

Figure 6. SP6641BEK - 3.3 Line/Load Rejection vs Load Current

100

95 90 85 80 75

Efficiency (%)

70 65 60

0.1 1.0 10.0 100.0 1000.0

Iload (mA

Vi=4.2V Vi=3.6V Vi=3.3V Vi=2.0V Vi=1.3V

Figure 7. SP6641AEK-5.0 Efficiency Vs Load Current

Rev. 5/26/05,

*Patent Pending

100

95 90

Vi=4.2V Vi=3.6V Vi=3.3V Vi=2.0V

Vi=1.3V

85 80 75

Efficiency (%)

70 65 60

0.1 1.0 10.0 100.0 1000.0

Iload (mA

Figure 8. SP6641BEK-5.0 Efficiency Vs Load Current

Page 5

PERFORMANCE CHARACTERISTICS

)

Refer to the circuit in Figure 1, T

= +25°C

AMB

5.200

5.180

5.160

5.140

5.120

5.100

Vo (V)

5.080

5.060

5.040

5.020

5.000 050100 150 200 250

Vi=4.2V Vi=3.6V Vi=3.3V Vi=2.0V Vi=1.3V

Iload (mA

Figure 9. SP6641AEK-5.0 Line/Load Rejection Vs Load Current

250

200

150

Iin (uA)

100

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

SP6641AEK-5.0 SP6641AEK-3.3

Vin (V

5.100

5.080

5.060

5.040

5.020

5.000

Vo (V)

4.980

4.960

4.940

4.920

4.900 0 200 400 600 800

Iload (mA)

Vi=4.2V Vi=3.6V Vi=3.3V Vi=2.0V Vi=1.3V

Figure 10. SP6641BEK-5.0 Line/Load Rejection Vs Load Current

500 450 400 350 300 250

Iin (uA)

200 150 100

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

Vin (V)

SP6641B-5.0 SP6641B-3.3

Figure 11. SP6641AEK-3.3 & SP6641AEK-5.0 No Load Battery Current

250

200

150

Io (mA)

100

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

SP6641AEK-3.3, 22µH SP6641AEK-3.3, 10µH

SP6641AEK-5.0, 22µH SP6641AEK-5.0, 10µH

Vin (V

Figure 13. SP6641AEK-3.3 & SP6641AEK-5.0 Maximum Resistive Load Current in Startup

Rev. 5/26/05,

*Patent Pending

Figure 12. SP6641BEK-3.3 & SP6641AEK-5.0 No Load Battery Current

700

600

500

400

Io (mA)

300

200

100

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

Vin (V

SP6641BEK-3.3, 22µH SP6641BEK-3.3, 10µH SP6641BEK-5.0, 22µH SP6641BEK-5.0, 10µH

Figure 14. SP6641BEK-3.3 & SP6641BEK-5.0 Maximum Resistive Load Current in Startup

Page 6

OPERATION

General Overview

The SP6641 is a high efficiency, low quiescent current step-up DC-DC converter ideal for single and dual cell alkaline and single cell Lithium Ion battery applications such as medical monitors, PDA’s, MP3 players, and other portable end products. The SP6641’s 10µA quiescent current, low 0.3Ω NFET switch, and unique PFM control scheme combine to provide excellent efficiency over a wide output power range.

Other features include a logic level enable control pin, guaranteed 0.9V startup, a tiny SOT23 5 pin package, and precise inductor peak current control. SP6641A sources up to 90mA at 1.3V, typ. and SP6641B sources up to 500mA at 2.6V, typ. by supporting different peak inductor current levels. Only two capacitors, an inductor, and a diode are required to build a power supply for the SP6641A. The SP6641B, 1A peak current requires an additional small resistor and capacitor as a low pass filter for the V

IC power pin.

OUT

Loop Regulation

The SP6641 combines a fixed inductor peak current limit, a feed-forward minimum off-time one-shot, and a precision loop comparator to regulate the output voltage. Under light-load conditions the loop operates as a standard PFM converter. The frequency of fixed amplitude inductor current triangles is modulated to regulate the load. Under heavy load conditions, the converter adjusts the number of successive continuous mode current pulses to regulate the load. Refer to the block diagram for the following explanation of operating modes in loop regulation.

The output voltage is internally divided down and fed to the negative terminal of the loop comparator. A +1.25V bandgap reference voltage is applied to the positive terminal of the comparator. As the output voltage droops below the regulation threshold due to the load the loop comparator output (signal V

OUT(LOW)

) transitions to a logic “1”. This sets the SR latch and initiates inductor charging by pulling the signal NGATE high. Inductor charging continues until the current reaches the internally programmed limit, at which point, the off-time one-shot is triggered.

The off-time one-shot via signal T SR latch regardless of the SET state (V

resets the

OFF

OUT(LOW)

opens the NMOS charge switch, and forces the

inductor to discharge through the rectifying diode for a minimum time defined by the oneshot duration. The end of the off-time pulse releases the SR latch, and its output state is once again determined by the output of the loop comparator (V

OUT(LOW)

). Under light load conditions, the output voltage will have been pulled above the regulation threshold during the minimum off-time, the signal V

OUT(LOW)

logic “0”, and the NMOS charging switch will remain open. The inductor current discharges until it reaches zero or the loop comparator triggers a new charge cycle.

Under a heavy load, the output voltage will remain below the regulation point at the end of the off-time pulse. In this condition, V has a logic value of 1 which immediately starts a new charge/discharge cycle defined by the peak inductor current and the minimum offtime. The inductor current will remain in a continuous conduction mode until the loop comparator indicates the output voltage is above the regulation threshold, and the inductor current will relax towards zero.

During continuous mode bursts, the inductor current frequency and ripple amplitude are controlled by the minimum off-time one-shot and the input and output voltage levels. The SP6641 sets the minimum off-time to:

OFF

K V V

= Off-time Constant, typically 1.5µs*V

OFF

= Output Voltage

OUT

= Input Voltage

Plugging the T

OFF

– VIN), where:

OUT

expression into the boost mode equations yields the maximum output current in regulation:

OUT

IPK –

) (

OUT(MAX)

≈ η (

V where: η = Efficiency, typically 0.80 to 0.90 I

= Programmed inductor peak current, typi-

cally 0.33A for the SP6641A, typically

1.0A for the SP6641B.

L= Inductor value

will be a

OUT(LOW)

OFF

)

Rev. 5/26/05,

*Patent Pending

Page 7

OPERATION Loop Regulation: continued

The SP6641 feed forward off-time control delivers more load current than constant off-time control because the input battery voltage drops during its life cycle. The term (IPK – K

OFF

/2L) is the average current delivered to the output capacitor during the discharge phase. This is constant with respect to input and output voltage. With constant off-time control, the average discharge current term becomes

(IPK-T

OFF

*(V

OUT-VIN

)/2L),

which decreases as the input voltage drops. Table 1 illustrates the average inductor current

delivered to the load during discharge versus the input voltage. The SP6641 feed forward offtime control and the constant off-time control are compared. For purposes of illustration, the off times of each control scheme are normalized at a typical two cell alkaline input voltage of

2.6V. The values used in Table 1 are: IPK = 0.33A L = 22µH V

= 3.3V

OUT

(SP6641) = 1.5V*µs/(3.3-VIN)

OFF

(constant) = 2.14µs

OFF

SP6641A Constant T

OFF

Avg I

OFF

Avg I

3.0 5.00µs 0.30A 2.14µs 0.32A

2.6 2.14µs 0.30A 2.14µs 0.30A

2.0 1.15µs 0.30A 2.14µs 0.27A

1.3 0.75µs 0.30A 2.14µs 0.23A

1.0 0.65µs 0.30A 2.14µs 0.22A

Table 1- Average IL vs. Input Voltage

The following equation defines the burst mode frequency under heavy load conditions:

BURST

(

OUT

– V

OFF

VIN – V

) (

+ VD –V

OUT

)

where: VD = Forward schottky drop, (0.4V, typ) VC = Average charging switch drop,

Rnmos*IPK, typically 0.1V

Ignoring the conduction losses of VD and VC, the burst frequency equation simplifies to:

BURST

OUT

– VIN)V

OFFVOUT

Startup

The internal regulator circuitry is bootstrapped to the V

pin. This requires a low voltage

OUT

oscillator and charging switch powered from the V

pin to pump up the output voltage until

BATT

the reference is established. The reference provides a REFREADY signal that determines when output control is handed over to the regulator. REFREADY shuts down the startup circuit and enables the regulator when the reference is valid and V

is above +1.9V. Once the regulator is

OUT

given control it will continue to pump up the output at full power until regulation is reached.

For two cell alkaline input voltages and above, the output voltage will be pulled above +1.9V quickly through the rectifying diode before the reference has a chance to establish. In this scenario the startup circuit will coarsely regulate around +2.8V until the REFREADY signal asserts. This keeps the output from overshooting in startup with higher input voltages.

Startup is guaranteed at +0.9V at room temperature with a 3kΩ load. Heavier loads will require

a higher input voltage.

Shutdown/Enable Control

Pin 4 of the device is a V

referred control

BATT

pin that shuts down the converter with the pin tied to ground, or enables the converter with the pin tied to V

. When the converter is shut-

BATT

down the power switch is opened and all circuit biasing is extinguished leaving only junction leakage currents on supply pins 3 and 5. The output voltage will droop to one diode drop below the battery voltage through the rectifying diode.

After pin 4 is brought high, the startup circuit is enabled and starts pumping up the output until REFREADY hands over control to the internal regulator.

Rev. 5/26/05,

*Patent Pending

Page 8

APPLICATION INFORMATION

Circuit Layout

Printed circuit board layout is a critical part of a power supply design. Poor designs can result in excessive EMI on the voltage gradients and feedback paths on the ground planes with applications involving high switching frequencies and large peak currents. Excessive EMI can result in instability or regulation errors. All power components should be placed on the PC board as closely as possible with the traces kept short, direct, and wide (>50mils or 1.25mm). Extra copper on the PC board should be integrated into ground as a pseudo-ground plane. On a multilayer PC board, route the star ground using component-side copper fill, then connect it to the internal ground plane using vias. For the SP6641A/6641B devices, input and output filter capacitors should be soldered with their ground pins as close together as possible in a star-ground configuration. The VOUT pin must be bypassed directly to ground as close to the SP6641A/6641B devices as possible (within

0.2in or 5mm). The DC-DC converter and any digital circuitry should be placed on the opposite corner of the PC board as far away from sensitive RF and analog input stages. Noisy traces, such as from the LX pin, should be kept away from the voltage-feedback VOUT node and separated from it using grounded copper to minimize EMI. See the SP6641A/6641B Evaluation Board Manual for PC Board Layout design details.

Component Selection

Selection of capacitors, inductors and schottky diodes for SP6641A and SP6641B power supply circuits can be made through the use of Table 1 component selection. Capacitor equivalent series resistance is a major contributor to output ripple, usually greater than 60%. Low ESR capacitors are recommended. Ceramic capacitors have the lowest ESR. Low-ESR tantalum capacitors may be a more acceptable solution having both a low ESR and lower cost than large ceramic capacitors. Designers should select input and output capacitors with a rating exceeding the peak inductor current. Do not

allow tantalum capacitors to exceed their ripplecurrent ratings. For example, in the SP6641A a 22µF, 6V, low-ESR, surface-mount tantalum output filter capacitor typically provides 60mV output ripple when stepping up from 1.3V to

3.3V at 20mA. An input filter capacitor can reduce peak currents drawn from the battery and improve efficiency. Low-ESR aluminum electrolytic capacitors are acceptable in some applications but standard aluminum electrolytic capacitors are not recommended.

In selecting an inductor, the saturation current specified for the inductor needs to be greater then the SP6641A/B peak current to avoid saturating the inductor, which would result in a loss in efficiency and could damage the inductor. The SP6641A evaluation board uses a Sumida CDRH5D28 22µH inductor with an Isat value of 0.9A and a DCR of 0.095Ω, which easily handles the Ipeak of 0.33A of the SP6641A and will deliver high efficiencies. The SP6641B evaluation board uses a Sumida CDRH5D28 10µH inductor with an Isat value of 1.3A and a DCR of 0.065Ω, which easily handles the Ipeak of 1.0A of the SP6641B and will deliver high efficiencies. Other inductors could be selected provided their Isat is greater than the Ipeak of the SP6641A/SP6641B.

Output Filter or LDO Regulator

Designers could add LC pi filters, linear postregulators, or shielding in applications necessary to address excessive noise, voltage ripple, or EMI concerns. The LC pi filter’s cutoff frequency should be at least a decade or two below the DC-DC converters’ switching frequency for the specified load and input voltage. The SP6201, a small SOT235pin 200mA Low Drop Out linear regulator can be used at the SP6641A/6641B output to reduce output noise and ripple. The schematic in figure 15 illustrates this circuit on the SP6641A Evaluation Board with the SP6641 3.3V output followed by the Sipex SP6201 3.0V output Low Drop Out linear regulator.

Rev. 5/26/05,

*Patent Pending

Page 9

APPLICATION INFORMATION: continued

Maximum Startup Current

It should be noted that for low input voltages the SP6641 startup circuit can not support large load currents at startup. In startup the SP6641 needs to boost the output from zero volts using a charge pump which has a limited current capacity. Once the output is greater than 1.7 to

1.9V the operate circuit takes over and the SP6641 can supply much more current. Curves of maximum resistive load current in startup for the SP6641A and SP6641B are shown in Figures 13 & 14 and can be compared with Figure 2, maximum load current in operation. Also, Table 2 provides SP6641A 3.3V resistive load current in startup for some low cost 1812 size

From the curves in Figures 13 and 14, you can see that for low input voltages, the 22µH inductor has more current capacity at startup than the 10µH inductor, due to more energy per charge cycle in the relationship

/2LI2. Thus for 1 cell applications, 22µH is recommended for more startup current than 10µH.

For 1-cell battery applications, it is recommended to apply any large load current after the SP6641 has started up, typically in a few millisecs. This is typically not a problem in many applications where the load is a processor whose load current is low until the processor voltage comes up.

chip inductors.

TABLE 1. COMPONENT SELECTION

INDUCTORS - SURFACE MOUNT

Sipex Inductance Manufacturer/ Series R Isat Size LxWxH Inductor Manufacturer Part Number (µH) Part Number (Ω) (A) (mm) Type Website

SP6641A Ipk = .33A 22 Sumida CDRH5D28-220 0.095 0.90 5.7x5.5x3 Shielded Ferrite Core www.sumida.com

SP6641A Ipk = .33A 22 Coilcraft DO1608C-223 0.370 0.70 6.6x4.5x2.9 Unshielded Ferrite Core www.coilcraft.com SP6641A Ipk = .33A 22 TDK NLC453232T-220 0.900 0.37 4.4x3.2x3.2 Unshielded Ferrite Core www.tdk.com SP6641A Ipk = .33A 22 Murata LQH43C220K04 0.600 0.42 4.5x3.2x2.6 Unshielded Ferrite Core www.murata.com

SP6641B Ipk = 1A 10 Sumida CDRH5D28-100 0.065 1.30 5.7x5.5x3 Shielded Ferrite Core www.sumida.com

SP6641B Ipk = 1A 10 Coilcraft DO1608C-103 0.160 1.10 6.6x4.5x2.9 Unshielded Ferrite Core www.coilcraft.com SP6641B Ipk = 1A 10 Murata LQH55DN100M01 0.077 1.70 5x5x4.7 Unshielded Ferrite Core www.murata.com SP6641B Ipk = 1A 22 Sumida CDRH6D28-220 0.128 1.20 6.7x6.5x3 Shielded Ferrite Core www.sumida.com SP6641B Ipk = 1A 22 Murata LQH55DN220M01 0.160 1.20 5x5x4.7 Unshielded Ferrite Core www.murata.com

Inductor Specification

CAPACITORS - SURFACE MOUNT & THRU-HOLE

Capacitor Specification

Sipex Capacitance Manufacturer/ (max) Current LxWxH Voltage Capacitor Manufacturer Part Number (µF) Part Number (Ω)@ 45°C (A) (mm) (V) Type Website

SP6641A Ipk = .33A 22 TDK C3225X5R0J226M 0.010 4.00 1210 6.3 SMT X5R Cer. www.tdk.com SP6641B Ipk = 1A 100 SANYO 10TPA100M 0.080 1.20 7343 6.3 SMT POSCAP Tant. www.sanyovideo.com

SP6641B Ipk = 1A 100 SANYO 16SA100M 0.030 2.70 8Dx10L 16.0 Thru-hole OS-CON www.sanyovideo.com

ESR Ripple Size

SCHOTTKY DIODE - SURFACE MOUNT

Diode Specification

Sipex Manufacturer/ VF @ IF IF(AV) Size LxWxH Reverse V Package Manufacturer Part Number Part Number (V) (A) (mm) (V) Type Website

SP6641A Ipk = .33A STMicro STPS0520Z 0.39 0.50 3.9x1.7x1.3 20 SOD-123 www.st.com SP6641B Ipk = 1A Zetex ZCHS2000 0.42 2.00 3x3x1.4 40 SOT23-6 www.zetex.com

Note: Components highlighted in bold are those used on the SP6641A or SP6641B Evaluation Board.

Rev. 5/26/05,

*Patent Pending

Page 10

APPLICATION INFORMATION: continued

+0.9V to +3.3V Input

BATT

22µH

SP6641

22µF

GND

OUT

22µF

BATT

SHDN

OUT

+3.3V

Figure 15. SP6641A 3.3V Evaluation Board with SP6201 LDO Regulator

SuperCap Application on the SP6641 Output

When the battery input to SP6641A is removed, the SP6641A output will end up in the charge mode and will slowly discharge a Supercap connected to the output. The typical Supercap of 0.22F will go from fully charged at 3.3V to less than 2V in 5 minutes. The following appli-

cation circuit in figure 16 is recommended to disconnect the SP6641 output from the SuperCap when the battery is removed. The small SOT233pin MOS switches are an inexpensive addition to the SP6641 circuit and work well to maintain SuperCap voltage to retain Non-Volatile CMOS Memory while a battery is changed.

GND

ENABLE

OUT

+3.0V

SP6201

OUT

RESET

C3 1µF

TABLE 2. SP6641A Resistive Load Current in Startup - low cost inductors

SP6641A APPLICATION CIRCUIT WITH PANASONIC INDUCTOR SP6641A APPLICATION CIRCUIT WITH TDK INDUCTOR

L1 = ELJ-PB220KF 22µH, IDCmax = 300mA, DCR = 1.0Ω L1 = NLC453232T-220K 22µH, IDCmax = 370mA, DCR = 0.9Ω

Startup V

V Ω VmAmA (max) V Ω VmAmA (max)

Load after after then Load after after then

(min) Startup Startup Load V

OUT

Startup Startup V

(min) Startup Startup Load

OUT

0.86 16000 3.31 0.2 37 0.86 16000 3.30 0.2 42

0.88 1500 3.31 2 39 0.88 1500 3.30 2 43

0.90 800 3.30 4 40 0.90 900 3.30 4 44

0.95 230 3.30 14 44 0.95 260 3.30 13 48

1.00 125 3.30 26 48 1.00 126 3.30 26 52

1.10 73 3.29 45 56 1.10 66 3.29 50 60

1.20 58 3.29 57 63 1.20 49 3.29 67 69

1.30 50 3.28 66 71 1.30 43 3.29 77 77

1.40 43 3.28 76 78 1.40 39 3.29 84 84

1.50 39 3.28 84 86 1.50 36 3.29 91 91

Rev. 5/26/05,

*Patent Pending

Startup

Page 11

APPLICATION INFORMATION: continued Low Battery Circuit for SP6641

Application

The circuit in figure 17 uses the Sipex SPX432 shunt regulator as a reference and comparator circuit to detect a low battery condition and give a high level, typically 1.7V output. When the battery is good, the SPX432 output is low, but not at ground but at 0.8V or about one Vbe below the 1.24V reference. To translate that level to a CMOS Low of less than 0.4V, an NPN and 2 signal diodes can be added to the SPX432

BATT

22µF

22µH

Diode Schottky

SP6641

GND

OUT

BATT

SHDN

1 2

output, as shown. The small SOT23-3pin SPX432 and 2N3904 bipolar transistor and diodes are small and inexpensive to add to the SP6641 circuit and work well to add a Battery Low detection circuit, with the addition of about 130µA current from 3.3V out. As a bonus, the output of this circuit can be used to drive the SP6641 SHDN_N pin 3 to GND when the battery is removed, which would reset the SP6641 and eliminate the need for the SuperCap Switch shown in figure 16.

2.7V, 0.9Ω PMOS

SOT23-3 IRLML6302

OUT

+3.3V

R1 1M

1 3

Q2 SOT23-3 IRLML2402

2.7V NMOS

3.3V to Nonvolatile Function

C3 .22F Supercap

22µF

Figure 16. SP6641A 3.3V with SuperCap Switch

BATT

22µF

22µH

BATT

SHDN

Diode Schottky

22µF

GND

SP6641

OUT

Figure 17. SP6641A 3.3V with Low Battery Detection

Rev. 5/26/05,

*Patent Pending

1.8V THRES. VTHRES = 1.24V(1 + R1/R2) R1

44k

R2 100k

R3 20k

REF

100k

SPX432M

SOT23-3

1N4148

Q2 2N3904

BATT GOOD

2V = BATT GOOD 0V = LOW BATT

R5 100k

3.3V

OUT

Page 12

PACKAGE: 5 Lead SOT23

D C

.10

SYMBOL

MIN MAX

0.90

0.00

0.90

0.25

0.09

2.80

2.60

1.50

0.35

1.45

0.15

1.30

0.50

0.20

3.10

3.00

1.75

0.55

DATUM 'A

0.20

Rev. 5/26/05,

*Patent Pending

0.95ref

1.90ref

Page 13

ORDERING INFORMATION

Part Number TOP MARK Temperature Range Package Type

SP6641AEK-3.3/TR ............. K1...................... -40°C to 85°C........

SP6641BEK-3.3/TR ............. L1 ...................... -40°C to 85°C........

SP6641AEK-5.0/TR ............. P1...................... -40°C to 85°C........

SP6641BEK-5.0/TR .............Q1...................... -40°C to 85°C........

(Tape & Reel) (Tape & Reel) (Tape & Reel) (Tape & Reel)

5-Pin SOT-23 5-Pin SOT-23 5-Pin SOT-23 5-Pin SOT-23

Available in lead free packaging. To order add “-L” suffix to part number. Example: SP6641AEK-3.3/TR = standard; SP6641AEK-L-3.3/TR = lead free, Top Mark “H4”. /TR = Tape and Reel

Pack quantity is 2,500 for SOT23.

Corporation

SIGNAL PROCESSING EXCELLENCE

Sipex Corporation Headquarters and

Sales Office

22 Linnell Circle Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: [email protected]

Sales Office

233 South Hillview Drive Milpitas, CA 95035 TEL: (408) 934-7500 FAX: (408) 935-7600

Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others.

Rev. 5/26/05,

*Patent Pending

Page 14