MIC2571
Micrel
4-76
1997
MIC2571
Single-Cell Switching Regulator
Preliminary 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 120
A.
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 in
2
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
120
A typical quiescent current
Complete regulator fits 0.3 in
2
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
C2
47F
16V
5V/5mA
C1*
47F
16V
1V to1.5V
1 Cell
2.85V
3.3V
5V
2
4
5
6
1
7
8
L1
150H
SYNC
D1
MBR0530
* Needed if battery is
4" from MIC2571
Circuit size < 0.3 in
2
excluding C1
Single-Cell to 3.3V DC-to-DC Converter
IN
SW
GND
MIC2571-1
C2
47F
16V
3.3V/8mA
C1*
47F
16V
1V to1.5V
1 Cell
2.85V
3.3V
5V
2
4
5
6
1
7
8
L1
150H
SYNC
D1
MBR0530
* Needed if battery is
4" from MIC2571
Circuit size < 0.3 in
2
excluding C1
1997
4-77
MIC2571
Micrel
4
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
1
2
3
4
8
7
6
5
SW
GND
NC
5V
IN
SYNC
2.85V
3.3V
MIC2571-1
Selectable Voltage
20kHz Frequency
1
2
3
4
8
7
6
5
IN
SYNC
FB
NC
SW
GND
NC
NC
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.
MIC2571
Micrel
4-78
1997
Electrical Characteristics
V
IN
= 1.5V; T
A
= 25
C, bold indicates 40
C
T
A
85
C; unless noted
Parameter
Condition
Min
Typ
Max
Units
Input Voltage
Startup guaranteed, I
SW
= 100mA
15
V
0.9
V
Quiescent Current
Output switch off
120
A
Fixed Feedback Voltage
MIC2571-1; V
2.85V pin
= V
OUT
, I
SW
= 100mA
2.85
V
MIC2571-1; V
3.3V pin
= V
OUT
, I
SW
= 100mA
3.30
V
MIC2571-1; V
5V pin
= V
OUT
, I
SW
= 100mA
5.00
V
Reference Voltage
MIC2571-2, [adj. voltage versions], I
SW
= 100mA, Note 1
220
mV
220
mV
Comparator Hysteresis
MIC2571-2, [adj. voltage versions]
6
mV
Output Hysteresis
MIC2571-1; V
2.85V pin
= V
OUT
, I
SW
= 100mA
65
mV
MIC2571-1; V
3.3V pin
= V
OUT
, I
SW
= 100mA
75
mV
MIC2571-1; V
5V pin
= V
OUT
, I
SW
= 100mA
120
mV
Feedback Current
MIC2571-1; V
2.85V pin
= V
OUT
4.5
A
MIC2571-1; V
3.3V pin
= V
OUT
4.5
A
MIC2571-1; V
5V pin
= V
OUT
4.5
A
MIC2571-2, [adj. voltage versions]; V
FB
= 0V
25
nA
Reference Line Regulation
1.0V
V
IN
12V
0.35
%/V
Switch Saturation Voltage
V
IN
= 1.0V, I
SW
= 200mA
200
mV
V
IN
= 1.2V, I
SW
= 600mA
400
mV
V
IN
= 1.5V, I
SW
= 800mA
500
mV
Switch Leakage Current
Output switch off, V
SW
= 36V
1
A
Oscillator Frequency
MIC2571-1, -2; I
SW
= 100mA
20
kHz
Maximum Output Voltage
36
V
Sync Threshold Voltage
0.7
V
Switch On Time
35
s
Currrent Limit
1.1
A
Duty Cycle
V
FB
< V
REF
, I
SW
= 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 (V
IN
) ..................................................... 18V
Switch Voltage (V
SW
) .................................................... 36V
Switch Current (I
SW
) ....................................................... 1A
Sync Voltage (V
SYNC
) .................................... 0.3V to 15V
Storage Temperature (T
A
) ....................... 65
C to +150
C
MSOP Power Dissipation (P
D
) ................................ 250mW
Operating Ratings
Supply Voltage (V
IN
) .................................... +0.9V to +15V
Ambient Operating Temperature (T
A
) ........ 40
C to +85
C
Junction Temperature (T
J
) ....................... 40
C to +125
C
MSOP Thermal Resistance
(
JA
) .......................... 240
C/W
1997
4-79
MIC2571
Micrel
4
Typical Characteristics
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
T
A
= 40
C
1.4V
1.3V
1.1V
1.2V
V
IN
= 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
T
A
= 25
C
V
IN
= 0.9V
1.0V
1.1V
1.2V
1.3V
1.4V
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
T
A
= 85
C
1.2V
1.0V
1.1V
V
IN
= 0.9V
1.4V
1.3V
15
20
25
30
-60 -30
0
30
60
90 120 150
OSC. FREQUENCY (kHz)
TEMPERATURE (
C)
Oscillator Frequency
vs. Temperature
V
IN
= 1.5V
I
SW
= 100mA
50
55
60
65
70
75
-60 -30
0
30
60
90 120 150
DUTY CYCLE (%)
TEMPERATURE (
C)
Oscillator Duty Cycle
vs. Temperature
V
IN
= 1.5V
I
SW
= 100mA
50
75
100
125
150
175
200
-60 -30
0
30
60
90 120 150
QUIESCENT CURRENT (
A)
TEMPERATURE (
C)
Quiescent Current
vs. Temperature
V
IN
= 1.5V
0
2
4
6
8
10
-60 -30
0
30
60
90 120 150
FEEDBACK CURRENT (
A)
TEMPERATURE (
C)
Feedback Current
vs. Temperature
V
IN
= 1.5V
MIC2571-1
0
10
20
30
40
50
-60 -30
0
30
60
90 120 150
FEEDBACK CURRENT (nA)
TEMPERATURE (
C)
Feedback Current
vs. Temperature
V
IN
= 2.5V
MIC2571-2
0
25
50
75
100
125
150
175
200
0
2
4
6
8
10
QUIESCENT CURRENT (
A)
SUPPLY VOLTAGE (V)
Quiescent Current
vs. Supply Voltage
40
C
+85
C
+25
C
0
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
1
10
100
1000
-60 -30
0
30
60
90 120 150
SWITCH LEAKAGE CURRENT (nA)
TEMPERATURE (
C)
Switch Leakage Current
vs. Temperature
0
25
50
75
100
125
150
-60 -30
0
30
60
90 120 150
OUTPUT HYSTERESIS (mV)
TEMPERATURE (
C)
Output Hysteresis
vs. Temperature
V
OUT
= 2.85V
3.3V
5V
MIC2571
Micrel
4-80
1997
Block Diagrams
Oscillator
0.22V
Reference
Driver
IN
V
BATT
2.85V
GND
SW
SYNC
3.3V
5V
V
OUT
MIC2571-1
Selectable Voltage Version with External Components
Oscillator
0.22V
Reference
Driver
IN
V
BATT
GND
SW
SYNC
MIC2571-2
V
OUT
FB
Adjustable Voltage Version with External Components
1997
4-81
MIC2571
Micrel
4
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 V
OUT
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 V
IN
or a
switching waveform running at a frequency and duty cycle set
by the oscillator. The continuous voltage equal to V
IN
happens when the voltage at the output (V
OUT
) 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 V
OUT
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.
5V
0V
5V
0mA
I
PEAK
V
IN
Supply
Voltage
Inductor
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
MIC2571
Micrel
4-82
1997
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.
a.
b.
c.
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 200m
ESR can cause 100mV of ripple at the
output due the capacitor only. Acceptable values of ESR are
typically in the 50m
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 (
s)
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
1
IN
SAT
1997
4-83
MIC2571
Micrel
4
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 V
OUT
. Therefore, when the
output switch is off, the voltage across the inductor is:
V = V
+ V
V
2
OUT
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 I
1
= I
2
to get:
V
t = V
t
1
1
2
2
V
V
=
t
t
1
2
2
1
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 t
1
is when V
IN
is
at its minimum value and the worst case for t
2
is when V
IN
is
at its maximum value (assuming that V
OUT
, V
DIODE
and V
SAT
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
is
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
t
1
L =
V
2
Average I
t
IN(min)
IN(max)
1
where t =
duty cycle
f
1
OSC
To illustrate the use of these equations a design example will
be given:
Assume:
MIC2571-1 (fixed oscillator)
V
OUT
= 5V
I
OUT(max)
=5mA
V
IN(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 = 525
H
Use the next lowest standard value of inductor and verify that
it does not saturate at a current below about 75mA
(< 2
33.3mA).
MIC2571
Micrel
4-84
1997
GND
5V
SW
MIC2571
SYNC
U1 Micrel
MIC2571-1BMM
C1 Sprague
594D476X0016C2T Tantalum ESR = 0.11
C2 Sprague
594D476X0016C2T Tantalum ESR = 0.11
D1 Motorola
MBR0530T1
L1
Coilcraft
DO1608C-154 DCR = 1.7
7
4
1
2
8
IN
C2
47F
16V
V
OUT
5V/5mA
1V to 1.5V
1 Cell
C1*
47F
16V
D1
MBR0530
L1
150H
* Needed if battery is more than 4" away from MIC2571
Example 1. 5V/5mA Regulator
GND
3.3V
SW
MIC2571
SYNC
U1 Micrel
MIC2571-1BMM
C1 Sprague
594D476X0016C2T Tantalum ESR = 0.11
C2 Sprague
594D476X0016C2T Tantalum ESR = 0.11
D1 Motorola
MBR0530T1
L1
Coilcraft
DO1608C-154 DCR = 1.7
7
5
1
2
8
IN
C2
47F
16V
V
OUT
3.3V/8mA
1V to 1.5V
1 Cell
C1*
47F
16V
D1
MBR0530
L1
150H
* Needed if battery is more than 4" away from MIC2571
Example 2. 3.3V/8mA Regulator
GND
FB
SW
MIC2571
SYNC
U1 Micrel
MIC2570-2BMM
C1 Sprague
594D476X0016C2T Tantalum ESR = 0.11
C2 Sprague
594D156X0025C2T Tantalum ESR = 0.22
D1 Motorola
MBRA0530T1
L1
Coilcraft
DO1608C-154 DCR = 1.7
7
6
1
2
8
IN
C2
15F
25V
V
OUT
12V/2mA
1.0V to 1.5V
1 Cell
C1*
47F
16V
D1
MBR0530
L1
150H
R2
1M
1%
R1
20k
1%
* Needed if battery is more than 4" away from MIC2571
V
OUT
= 0.22V (1 + R2/R1)
Example 3. 12V/40mA Regulator
Application Examples
1997
4-85
MIC2571
Micrel
4
GND
5V
SW
MIC2571
SYNC
U1 Micrel
MIC2571-1BMM
C1 Sprague
594D476X0016C2T Tantalum ESR = 0.11
C2 Sprague
594D476X0016C2T Tantalum ESR = 0.11
C3 Sprague
594D476X0016C2T Tantalum ESR = 0.11
C4 Sprague
594D476X0016C2T Tantalum ESR = 0.11
D1 Motorola
MBR0530T1
D2 Motorola
MBR0530T1
D3 Motorola
MBR0530T1
L1
Coilcraft
DO1608C-154 DCR = 1.7
7
4
1
2
8
IN
C2
47F
16V
V
OUT
/+I
OUT
5V/2mA
1V to 1.5V
1 Cell
C1*
47F
16V
D1
MBR0530
L1
150H
* Needed if battery is more than 4" away from MIC2571
C3
47F
16V
D2
MBR0530
D3
MBR0530
R1
220k
C4
47F
16V
V
OUT
/I
OUT
5V/2mA
I
OUT
+I
OUT
Example 4.
5V/2mA Regulator
GND
5V
SW
MIC2571
SYNC
U1 Micrel
MIC2571-1BMM
C1 AVX
TPSD107M010R0100 Tantalum ESR = 0.1
C2 AVX
TPSD107M010R0100 Tantalum ESR = 0.1
D1 Motorola
MBRA140T3
L1
Coilcraft
DO3308P-473 DCR = 0.32
7
4
1
2
8
IN
C2
100F
10V
V
OUT
5V/15mA
1V to 1.5V
1 Cell
C1
100F
10V
D1
MBRA140
L1
47H
R1
51k
Q1
2N3906
Minimum Start-Up Supply Voltage
V
IN
= 1V, I
LOAD
= 0A
V
IN
= 1.2V, I
LOAD
= 15mA
Example 5. 5V/15mA Regulator
GND
FB
SW
MIC2571
SYNC
U1 Micrel
MIC2571-2BM
C1 Sprague
594D476X0016C2T Tantalum ESR = 0.11
C2 Sprague
594D156X0025C2T Tantalum ESR = 0.22
C3 Sprague
594D156X0025C2T Tantalum ESR = 0.22
D1 Motorola
MBR0530T1
D2 Motorola
MBR0530T1
L1
Coilcraft
DO1608C-154 DCR = 1.7
7
6
1
2
8
IN
C2
0.1F
C1
47F
16V
D3
1N4148
L1
150H
R2
1.1MEG
1.1%
R1
20k
1%
1V to 1.5V
1 Cell
R3
220k
C2
15F
25V
V
OUT
12V/2mA
D2
MBR0530
D1
MBR0530
C1
15F
25V
V
OUT
= 0.22V *(1+R2/R1) + 0.6V
Example 6. 12V/2mA Regulator
MIC2571
Micrel
4-86
1997
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
PDF 
ZIP