MIC2571-1YMM - MICROCHIP TECHNOLOGY

1997 1 MIC2571

MIC2571 Micrel

MIC2571

Single-Cell Switching Regulator

Final Information

General Description

Micrel’s MIC2571 is a micropower boost switching regulator

that operates from one alkaline, nickel-metal-hydride cell, or

lithium cell.

The MIC2571 accepts a positive input voltage between 0.9V

and 15V. Its typical no-load supply current is 120µA.

The MIC2571 is available in selectable fixed output or adjust-

able output versions. The MIC2571-1 can be configured for

2.85V, 3.3V, or 5V by connecting one of three separate

feedback pins to the output. The MIC2571-2 can be config-

ured for an output voltage ranging between its input voltage

and 36V, using an external resistor network.

The MIC2571 has a fixed switching frequency of 20kHz. An

external SYNC connection allows the switching frequency to

be synchronized to an external signal.

The MIC2571 requires only four components (diode, induc-

tor, input capacitor and output capacitor) to implement a

boost regulator. A complete regulator can be constructed in

a 0.3 in2 area.

All versions are available in an 8-lead MSOP with an operat-

ing range from –40°C to +85°.

Typical Applications

Features

• Operates from a single-cell supply

0.9V to 15V operation

• 120µA typical quiescent current

• Complete regulator fits 0.3 in2 area

• 2.85V/3.3V/5V selectable output voltage (MIC2571-1)

• Adjustable output up to 36V (MIC2571-2)

• 1A current limited pass element

• Frequency synchronization input

• 8-lead MSOP package

Applications

• Pagers

• LCD bias generator

• Battery-powered, hand-held instruments

• Palmtop computers

• Remote controls

• Detectors

• Battery Backup Supplies

Single-Cell to 5V DC-to-DC Converter

IN SW

GND

MIC2571-1

47µF

16V

5V/5mA

C1*

47µF

16V

1V to1.5V

1 Cell 2.85V

3.3V

150µH

SYNC

MBR0530

* Needed if battery is ≥ 4" from MIC2571

Circuit size < 0.3 in

excluding C1

Single-Cell to 3.3V DC-to-DC Converter

IN SW

GND

MIC2571-1

47µF

16V

3.3V/8mA

C1*

47µF

16V

1V to1.5V

1 Cell 2.85V

3.3V

150µH

SYNC

MBR0530

* Needed if battery is ≥ 4" from MIC2571

Circuit size < 0.3 in

excluding C1

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com

MIC2571 Micrel

MIC2571 2 1997

Ordering Information

Part Number Temperature Range Voltage Frequency Package

MIC2571-1BMM –40°C to +85°C Selectable* 20kHz 8-lead MSOP

MIC2571-2BMM –40°C to +85°C Adjustable 20kHz 8-lead MSOP

* Externally selectable for 2.85V, 3.3V, or 5V

Pin Configuration

GND

SYNC

2.85V

3.3V

MIC2571-1

Selectable Voltage

20kHz Frequency

SYNC

GND

MIC2571-2

Adjustable Voltage

20kHz Frequency

8-Lead MSOP (MM)

Pin Description

Pin No. (Version†) Pin Name Pin Function

1 SW Switch: NPN output switch transistor collector.

2 GND Power Ground: NPN output switch transistor emitter.

3 NC Not internally connected.

4 (-1) 5V 5V Feedback (Input): Fixed 5V feedback to internal resistive divider.

4 (-2) NC Not internally connected.

5 (-1) 3.3V 3.3V Feedback (Input): Fixed 3.3V feedback to internal resistive divider.

5 (-2) NC Not internally connected.

6 (-1) 2.85V 2.85V Feedback (Input): Fixed 2.85V feedback to internal resistive divider.

6 (-2) FB Feedback (Input): 0.22V feedback from external voltage divider network.

7 SYNC Synchronization (Input): Oscillator start timing. Oscillator synchronizes to

falling edge of sync signal.

8 IN Supply (Input): Positive supply voltage input.

† Example: (-1) indicates the pin description is applicable to the MIC2571-1 only.

1997 3 MIC2571

MIC2571 Micrel

Electrical Characteristics

VIN = 1.5V; TA = 25°C, bold indicates –40°C≤ TA≤ 85°C; unless noted

Parameter Condition Min Typ Max Units

Input Voltage Startup guaranteed, ISW = 100mA 15 V

0.9 V

2.7

3.14

4.75

3.0

3.47

5.25

208 232

Quiescent Current Output switch off 120 µA

Fixed Feedback Voltage MIC2571-1; V2.85V pin = VOUT, ISW = 100mA 2.85 V

MIC2571-1; V3.3V pin = VOUT, ISW = 100mA 3.30 V

MIC2571-1; V5V pin = VOUT, ISW = 100mA 5.00 V

Reference Voltage MIC2571-2, [adj. voltage versions], ISW = 100mA, Note 1 220 mV

Comparator Hysteresis MIC2571-2, [adj. voltage versions] 6 mV

Output Hysteresis MIC2571-1; V2.85V pin = VOUT, ISW = 100mA 65 mV

MIC2571-1; V3.3V pin = VOUT, ISW = 100mA 75 mV

MIC2571-1; V5V pin = VOUT, ISW = 100mA 120 mV

Feedback Current MIC2571-1; V2.85V pin = VOUT 4.5 µA

MIC2571-1; V3.3V pin = VOUT 4.5 µA

MIC2571-1; V5V pin = VOUT 4.5 µA

MIC2571-2, [adj. voltage versions]; VFB = 0V 25 nA

Reference Line Regulation 1.0V ≤ VIN ≤ 12V 0.35 %/V

Switch Saturation Voltage VIN = 1.0V, ISW = 200mA 200 mV

VIN = 1.2V, ISW = 600mA 400 mV

VIN = 1.5V, ISW = 800mA 500 mV

Switch Leakage Current Output switch off, VSW = 36V 1 µA

Oscillator Frequency MIC2571-1, -2; ISW = 100mA 20 kHz

Maximum Output Voltage 36 V

Sync Threshold Voltage 0.7 V

Switch On Time 35 µs

Currrent Limit 1.1 A

Duty Cycle VFB < VREF, ISW = 100mA 67 %

General Note: Devices are ESD protected; however, handling precautions are recommended.

Note 1: Measured using comparator trip point.

Absolute Maximum Ratings

Supply Voltage (VIN) ..................................................... 18V

Switch Voltage (VSW) .................................................... 36V

Switch Current (ISW) ....................................................... 1A

Sync Voltage (VSYNC) .................................... –0.3V to 15V

Storage Temperature (TA) ....................... –65°C to +150°C

MSOP Power Dissipation (PD) ................................ 250mW

Operating Ratings

Supply Voltage (VIN) .................................... +0.9V to +15V

Ambient Operating Temperature (TA) ........ –40°C to +85°C

Junction Temperature (TJ) ....................... –40°C to +125°C

MSOP Thermal Resistance (θJA) .......................... 240°C/W

MIC2571 Micrel

MIC2571 4 1997

Typical Characteristics

0.2

0.4

0.6

0.8

1.0

0 0.2 0.4 0.6 0.8 1.0

SWITCH CURRENT (A)

SWITCH VOLTAGE (V)

Switch Saturation Voltage

TA = –40°C

1.4V

1.3V

1.1V

1.2V

VIN = 1.0V 0

0.2

0.4

0.6

0.8

1.0

0 0.2 0.4 0.6 0.8 1.0

SWITCH CURRENT (A)

SWITCH VOLTAGE (V)

Switch Saturation Voltage

TA = 25°C

= 0.9V

1.0V

1.1V

1.2V

1.3V

1.4V

0.2

0.4

0.6

0.8

1.0

0 0.2 0.4 0.6 0.8 1.0

SWITCH CURRENT (A)

SWITCH VOLTAGE (V)

Switch Saturation Voltage

TA = 85°C1.2V

1.0V

1.1V

VIN = 0.9V

1.4V 1.3V

-60 -30 0 30 60 90 120 150

OSC. FREQUENCY (kHz)

TEMPERATURE (°C)

Oscillator Frequency

vs. Temperature

VIN = 1.5V

ISW = 100mA

-60 -30 0 30 60 90 120 150

DUTY CYCLE (%)

TEMPERATURE (°C)

Oscillator Duty Cycle

vs. Temperature

VIN = 1.5V

ISW = 100mA

100

125

150

175

200

-60 -30 0 30 60 90 120 150

QUIESCENT CURRENT (µA)

TEMPERATURE (°C)

Quiescent Current

vs. Temperature

VIN = 1.5V

-60 -30 0 30 60 90 120 150

FEEDBACK CURRENT (µA)

TEMPERATURE (°C)

Feedback Current

vs. Temperature

VIN = 1.5V

MIC2571-1

-60 -30 0 30 60 90 120 150

FEEDBACK CURRENT (nA)

TEMPERATURE (°C)

Feedback Current

vs. Temperature

VIN = 2.5V

MIC2571-2

100

125

150

175

200

0246810

QUIESCENT CURRENT (µA)

SUPPLY VOLTAGE (V)

Quiescent Current

vs. Supply Voltage

–40°C

+85°C

+25°C

0.25

0.50

0.75

1.00

1.25

1.50

1.75

-60 -30 0 30 60 90 120 150

CURRENT LIMIT (A)

TEMPERATURE (°C)

Output Current Limit

vs. Temperature

0.01

0.1

100

1000

-60 -30 0 30 60 90 120 150

SWITCH LEAKAGE CURRENT (nA)

TEMPERATURE (°C)

Switch Leakage Current

vs. Temperature

100

125

150

-60 -30 0 30 60 90 120 150

OUTPUT HYSTERESIS (mV)

TEMPERATURE (°C)

Output Hysteresis

vs. Temperature

VOUT = 2.85V

3.3V

1997 5 MIC2571

MIC2571 Micrel

Block Diagrams

Oscillator

0.22V

Reference Driver

BATT

2.85V GND

SYNC

3.3V5V

OUT

MIC2571-1

Selectable Voltage Version with External Components

Oscillator

0.22V

Reference Driver

BATT

GND

SYNC

MIC2571-2

OUT

Adjustable Voltage Version with External Components

MIC2571 Micrel

MIC2571 6 1997

Functional Description

The MIC2571 switch-mode power supply (SMPS) is a gated

oscillator architecture designed to operate from an input

voltage as low as 0.9V and provide a high-efficiency fixed or

adjustable regulated output voltage. One advantage of this

architecture is that the output switch is disabled whenever the

output voltage is above the feedback comparator threshold

thereby greatly reducing quiescent current and improving

efficiency, especially at low output currents.

Refer to the Block Diagrams for the following discription of

typical gated oscillator boost regulator function.

The bandgap reference provides a constant 0.22V over a

wide range of input voltage and junction temperature. The

comparator senses the output voltage through an internal or

external resistor divider and compares it to the bandgap

reference voltage.

When the voltage at the inverting input of the comparator is

below 0.22V, the comparator output is high and the output of

the oscillator is allowed to pass through the AND gate to the

output driver and output switch. The output switch then turns

on and off storing energy in the inductor. When the output

switch is on (low) energy is stored in the inductor; when the

switch is off (high) the stored energy is dumped into the output

capacitor which causes the output voltage to rise.

When the output voltage is high enough to cause the com-

parator output to be low (inverting input voltage is above

0.22V) the AND gate is disabled and the output switch

remains off (high). The output switch remains disabled until

the output voltage falls low enough to cause the comparator

output to go high.

There is about 6mV of hysteresis built into the comparator to

prevent jitter about the switch point. Due to the gain of the

feedback resistor divider the voltage at VOUT experiences

about 120mV of hysteresis for a 5V output.

Appications Information

Oscillator Duty Cycle and Frequency

The oscillator duty cycle is set to 67% which is optimized to

provide maximum load current for output voltages approxi-

mately 3× larger than the input voltage. Other output voltages

are also easily generated but at a small cost in efficiency. The

fixed oscillator frequency (options -1 and -2) is set to 20kHz.

Output Waveforms

The voltage waveform seen at the collector of the output

switch (SW pin) is either a continuous value equal to VIN or a

switching waveform running at a frequency and duty cycle set

by the oscillator. The continuous voltage equal to VIN

happens when the voltage at the output (VOUT) is high

enough to cause the comparator to disable the AND gate. In

this state the output switch is off and no switching of the

inductor occurs. When VOUT drops low enough to cause the

comparator output to change to the high state the output

switch is driven by the oscillator. See Figure 1 for typical

voltage waveforms in a boost application.

0mA

IPEAK

VIN

Supply

Voltage

Peak

Current

Output

Voltage

Time

Figure 1. Typical Boost Regulator Waveforms

Synchronization

The SYNC pin is used to synchronize the MIC2571 to an

external oscillator or clock signal. This can reduce system

noise by correlating switching noise with a known system

frequency. When not in use, the SYNC pin should be

grounded to prevent spurious circuit operation. A falling edge

at the SYNC input triggers a one-shot pulse which resets the

oscillator. It is possible to use the SYNC pin to generate

oscillator duty cycles from approximately 20% up to the

nominal duty cycle.

Current Limit

Current limit for the MIC2571 is internally set with a resistor.

It functions by modifying the oscillator duty cycle and fre-

quency. When current exceeds 1.2A, the duty cycle is

reduced (switch on-time is reduced, off-time is unaffected)

and the corresponding frequency is increased. In this way

less time is available for the inductor current to build up while

maintaining the same discharge time. The onset of current

limit is soft rather than abrupt but sufficient to protect the

inductor and output switch from damage. Certain combina-

tions of input voltage, output voltage and load current can

cause the inductor to go into a continuous mode of operation.

This is what happens when the inductor current can not fall to

zero and occurs when:

duty cycle V + V – V

V + V – V

OUT DIODE IN

OUT DIODE SAT

≤

Time

Inductor Current

Current "ratchet"

without current limit

Current limit threshold

Continuous current

Discontinuous current

Figure 2. Current Limit Behavior

1997 7 MIC2571

MIC2571 Micrel

Figure 2 shows an example of inductor current in the continu-

ous mode with its associated change in oscillator frequency

and duty cycle. This situation is most likely to occur with

relatively small inductor values, large input voltage variations

and output voltages which are less than ~3× the input voltage.

Selection of an inductor with a saturation threshold above

1.2A will insure that the system can withstand these condi-

tions.

Inductors, Capacitors and Diodes

The importance of choosing correct inductors, capacitors and

diodes can not be ignored. Poor choices for these compo-

nents can cause problems as severe as circuit failure or as

subtle as poorer than expected efficiency.

Inductor Current

Time

Figure 3. Inductor Current: a. Normal,

b. Saturating and c. Excessive ESR

Inductors

Inductors must be selected such that they do not saturate

under maximum current conditions. When an inductor satu-

rates, its effective inductance drops rapidly and the current

can suddenly jump to very high and destructive values.

Figure 3 compares inductors with currents that are correct

and unacceptable due to core saturation. The inductors have

the same nominal inductance but Figure 3b has a lower

saturation threshold. Another consideration in the selection

of inductors is the radiated energy. In general, toroids have

the best radiation characteristics while bobbins have the

worst. Some bobbins have caps or enclosures which signifi-

cantly reduce stray radiation.

The last electrical characteristic of the inductor that must be

considered is ESR (equivalent series resistance). Figure 3c

shows the current waveform when ESR is excessive. The

normal symptom of excessive ESR is reduced power transfer

efficiency. Note that inductor ESR can be used to the

designers advantage as reverse battery protection (current

limit) for the case of relatively low output power one-cell

designs. The potential for very large and destructive currents

exits if a battery in a one-cell application is inserted back-

wards into the circuit. In some applications it is possible to

limit the current to a nondestructive (but still battery draining)

level by choosing a relatively high inductor ESR value which

does not affect normal circuit performance.

Capacitors

It is important to select high-quality, low ESR, filter capacitors

for the output of the regulator circuit. High ESR in the output

capacitor causes excessive ripple due to the voltage drop

across the ESR. A triangular current pulse with a peak of

500mA into a 200mΩ ESR can cause 100mV of ripple at the

output due the capacitor only. Acceptable values of ESR are

typically in the 50mΩ range. Inexpensive aluminum electro-

lytic capacitors usually are the worst choice while tantalum

capacitors are typically better. Figure 4 demonstrates the

effect of capacitor ESR on output ripple voltage.

4.75

5.00

5.25

0 500 1000 1500

OUTPUT VOLTAGE (V)

TIME (µs)

Figure 4. Output Ripple

Output Diode

Finally, the output diode must be selected to have adequate

reverse breakdown voltage and low forward voltage at the

application current. Schottky diodes typically meet these

requirements.

Standard silicon diodes have forward voltages which are too

large except in extremely low power applications. They can

also be very slow, especially those suited to power rectifica-

tion such as the 1N400x series, which affects efficiency.

Inductor Behavior

The inductor is an energy storage and transfer device. Its

behavior (neglecting series resistance) is described by the

following equation:

I = V

L t×

where:

V = inductor voltage (V)

L = inductor value (H)

t = time (s)

I = inductor current (A)

If a voltage is applied across an inductor (initial current is

zero) for a known time, the current flowing through the

inductor is a linear ramp starting at zero, reaching a maximum

value at the end of the period. When the output switch is on,

the voltage across the inductor is:

V = V – V

1INSAT

MIC2571 Micrel

MIC2571 8 1997

When the output switch turns off, the voltage across the

inductor changes sign and flies high in an attempt to maintain

a constant current. The inductor voltage will eventually be

clamped to a diode drop above VOUT. Therefore, when the

output switch is off, the voltage across the inductor is:

V = V + V – V

2OUT DIODE IN

For normal operation the inductor current is a triangular

waveform which returns to zero current (discontinuous mode)

at each cycle. At the threshold between continuous and

discontinuous operation we can use the fact that I1 = I2 to get:

V t = V t

11 2 2

××

V = tt

This relationship is useful for finding the desired oscillator

duty cycle based on input and output voltages. Since input

voltages typically vary widely over the life of the battery, care

must be taken to consider the worst case voltage for each

parameter. For example, the worst case for t1 is when VIN is

at its minimum value and the worst case for t2 is when VIN is

at its maximum value (assuming that VOUT, VDIODE and VSAT

do not change much).

To select an inductor for a particular application, the worst

case input and output conditions must be determined. Based

on the worst case output current we can estimate efficiency

and therefore the required input current. Remember that this

power

conversion, so the worst case average input current

will occur at maximum output current and minimum input

voltage.

Average I = V I

V Efficiency

IN(max) OUT OUT(max)

IN(min)

Referring to Figure 1, it can be seen the peak input current will

be twice the average input current. Rearranging the inductor

equation to solve for L:

L = V

I t1

L = V

2 Average I t

IN(min)

IN(max) 1

××

where t = duty cycle

1OSC

To illustrate the use of these equations a design example will

be given:

Assume:

MIC2571-1 (fixed oscillator)

VOUT = 5V

IOUT(max) =5mA

VIN(min) = 1.0V

efficiency = 75%.

Average I = 5V 5mA

1.0V 0.75 = 33.3mA

IN(max) ××

L = 1.0V 0.7

2 33.3mA 20kHz

××

L = 525µH

Use the next lowest standard value of inductor and verify that

it does not saturate at a current below about 75mA

(< 2 × 33.3mA).

1997 9 MIC2571

MIC2571 Micrel

GND 5V

MIC2571

SYNC

U1 Micrel MIC2571-1BMM

C1 Sprague 594D476X0016C2T Tantalum ESR = 0.11Ω

C2 Sprague 594D476X0016C2T Tantalum ESR = 0.11Ω

D1 Motorola MBR0530T1

L1 Coilcraft DO1608C-154 DCR = 1.7Ω

47µF

16V

VOUT

5V/5mA

1V to 1.5V

1 Cell C1*

47µF

16V

MBR0530

150µH

* Needed if battery is more than 4" away from MIC2571

Example 1. 5V/5mA Regulator

GND

3.3V

MIC2571

SYNC

U1 Micrel MIC2571-1BMM

C1 Sprague 594D476X0016C2T Tantalum ESR = 0.11Ω

C2 Sprague 594D476X0016C2T Tantalum ESR = 0.11Ω

D1 Motorola MBR0530T1

L1 Coilcraft DO1608C-154 DCR = 1.7Ω

47µF

16V

VOUT

3.3V/8mA

1V to 1.5V

1 Cell C1*

47µF

16V

MBR0530

150µH

* Needed if battery is more than 4" away from MIC2571

Example 2. 3.3V/8mA Regulator

GND FB

MIC2571

SYNC

U1 Micrel MIC2570-2BMM

C1 Sprague 594D476X0016C2T Tantalum ESR = 0.11Ω

C2 Sprague 594D156X0025C2T Tantalum ESR = 0.22Ω

D1 Motorola MBRA0530T1

L1 Coilcraft DO1608C-154 DCR = 1.7Ω

15µF

25V

OUT

12V/2mA

1.0V to 1.5V

1 Cell C1*

47µF

16V

MBR0530

150µH

20k

* Needed if battery is more than 4" away from MIC2571

OUT

= 0.22V (1 + R2/R1)

Example 3. 12V/40mA Regulator

Application Examples

MIC2571 Micrel

MIC2571 10 1997

GND 5V

MIC2571

SYNC

U1 Micrel MIC2571-1BMM

C1 Sprague 594D476X0016C2T Tantalum ESR = 0.11Ω

C2 Sprague 594D476X0016C2T Tantalum ESR = 0.11Ω

C3 Sprague 594D476X0016C2T Tantalum ESR = 0.11Ω

C4 Sprague 594D476X0016C2T Tantalum ESR = 0.11Ω

D1 Motorola MBR0530T1

D2 Motorola MBR0530T1

D3 Motorola MBR0530T1

L1 Coilcraft DO1608C-154 DCR = 1.7Ω

47µF

16V

VOUT/+IOUT

5V/2mA

1V to 1.5V

1 Cell C1*

47µF

16V

MBR0530

150µH

* Needed if battery is more than 4" away from MIC2571

47µF

16V

MBR0530

MBR0530 R1

220k C4

47µF

16V –VOUT/–IOUT

–5V/2mA

–IOUT ≤ +IOUT

Example 4. ±5V/2mA Regulator

GND 5V

MIC2571

SYNC

U1 Micrel MIC2571-1BMM

C1 AVX TPSD107M010R0100 Tantalum ESR = 0.1Ω

C2 AVX TPSD107M010R0100 Tantalum ESR = 0.1Ω

D1 Motorola MBRA140T3

L1 Coilcraft DO3308P-473 DCR = 0.32Ω

100µF

10V

VOUT

5V/15mA

1V to 1.5V

1 Cell

100µF

10V

MBRA140

47µH

51k

2N3906

Minimum Start-Up Supply Voltage

VIN = 1V, ILOAD = 0A

VIN = 1.2V, ILOAD = 15mA

Example 5. 5V/15mA Regulator

GND FB

MIC2571

SYNC

U1 Micrel MIC2571-2BM

C1 Sprague 594D476X0016C2T Tantalum ESR = 0.11Ω

C2 Sprague 594D156X0025C2T Tantalum ESR = 0.22Ω

C3 Sprague 594D156X0025C2T Tantalum ESR = 0.22Ω

D1 Motorola MBR0530T1

D2 Motorola MBR0530T1

L1 Coilcraft DO1608C-154 DCR = 1.7Ω

0.1µF

47µF

16V

1N4148

150µH

1.1M

1.1%

20k

1V to 1.5V

1 Cell

220k C2

15µF

25V –V

OUT

–12V/2mA

MBR0530

15µF

25V

–V

OUT

= – 0.22V (1+R2/R1) + 0.6V

Example 6. –12V/2mA Regulator

1997 11 MIC2571

MIC2571 Micrel

Suggested Manufacturers List

Inductors Capacitors Diodes

Coilcraft AVX Corp. General Instruments (GI)

1102 Silver Lake Rd. 801 17th Ave. South 10 Melville Park Rd.

Cary, IL 60013 Myrtle Beach, SC 29577 Melville, NY 11747

PH (708) 639-2361 PH (803) 448-9411 PH (516) 847-3222

FX (708) 639-1469 FX (803) 448-1943 FX (516) 847-3150

Coiltronics Sanyo Video Components Corp. International Rectifier Corp.

6000 Park of Commerce Blvd. 2001 Sanyo Ave. 233 Kansas St.

Boca Raton, FL 33487 San Diego, CA 92173 El Segundo, CA 90245

PH (407) 241-7876 PH (619) 661-6835 PH (310) 322-3331

FX (407) 241-9339 FX (619) 661-1055 FX (310) 322-3332

Sumida Sprague Electric Motorola Inc.

637 E. Golf Road, Suite 209 Lower Main Street 3102 North 56th St.

Arlington Heights, IL 60005Sanford, ME 04073 MS 56-126

PH (708) 956-0666 PH (207) 324-4140 Phoenix, AZ 85018

FX (708) 956-0702 PH (602) 244-3576

FX (602) 244-4015

Component Side and Silk Screen (Not Actual Size)

Solder Side and Silk Screen (Not Actual Size)

Evaluation Board Layout

MIC2571 Micrel

MIC2571 12 1997

Package Information

0.008 (0.20)

0.004 (0.10) 0.039 (0.99)

0.035 (0.89)

0.021 (0.53)

0.012 (0.03) R

0.0256 (0.65) TYP

0.012 (0.30) R

5° MAX

0° MIN

0.122 (3.10)

0.112 (2.84)

0.120 (3.05)

0.116 (2.95)

0.012 (0.03)

0.007 (0.18)

0.005 (0.13)

0.043 (1.09)

0.038 (0.97)

0.036 (0.90)

0.032 (0.81)

DIMENSIONS:

INCH (MM)

0.199 (5.05)

0.187 (4.74)

8-Pin MSOP (MM)

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