Page 1
MIC2571 Micrel
IN
SW
GND
MIC2571-1
C2
47µF
16V
3.3V/8mA
C1*
47µF
16V
1V to1.5V
1 Cell
2.85V
3.3V
5V
2
4
5
6
1
7
8
L1
150µH
SYNC
D1
MBR0530
* Needed if battery is ≥ 4" from MIC2571
Circuit size < 0.3 in
2
excluding C1
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 120µA.
The MIC2571 is available in selectable fixed output or adjustable 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 configured 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, inductor, 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 operating range from –40°C to +85°.
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
T ypical Applications
C1*
47µF
16V
* Needed if battery is ≥ 4" from MIC2571
Circuit size < 0.3 in
Single-Cell to 5V DC-to-DC Converter
1V to1.5V
1 Cell
MIC2571-1
IN
SYNC
7
2
excluding C1
8
150µH
2.85V
GND
2
L1
SW
3.3V
5V
1
6
5
4
D1
MBR0530
C2
47µF
16V
5V/5mA
Single-Cell to 3.3V DC-to-DC Converter
4-76 1997
Page 2
MIC2571 Micrel
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
MIC2571-1
SW
GND
NC
5V
1
2
3
4
8
7
6
5
IN
SYNC
2.85V
3.3V
Selectable 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.
MIC2571-2
1
SW
2
GND
3
NC
4
NC
Adjustable Voltage
20kHz Frequency
8
7
6
5
IN
SYNC
FB
NC
4
1997 4-77
Page 3
MIC2571 Micrel
Absolute Maximum Ratings
Supply Voltage (VIN) .....................................................18V
Switch Voltage (VSW)....................................................36V
Switch Current (ISW) .......................................................1A
Sync Voltage (V
) .................................... –0.3V to 15V
SYNC
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
Storage Temperature (TA) ....................... –65°C to +150°C
MSOP Power Dissipation (PD)................................250mW
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, I
Quiescent Current Output switch off 120 µA
Fixed Feedback Voltage MIC2571-1; V
MIC2571-1; V
MIC2571-1; V
2.85V pin
3.3V pin
5V pin
Reference Voltage MIC2571-2, [adj. voltage versions], I
Comparator Hysteresis MIC2571-2, [adj. voltage versions] 6 mV
Output Hysteresis MIC2571-1; V
MIC2571-1; V
MIC2571-1; V
Feedback Current MIC2571-1; V
MIC2571-1; V
MIC2571-1; V
MIC2571-2, [adj. voltage versions]; VFB = 0V 25 nA
2.85V pin
3.3V pin
5V pin
2.85V pin
3.3V pin
5V pin
Reference Line Regulation 1.0V ≤ VIN ≤ 12V 0.35 %/V
Switch Saturation Voltage V
= 1.0V, ISW = 200mA 200 mV
IN
V
= 1.2V, ISW = 600mA 400 mV
IN
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 µ s
Currrent Limit 1.1 A
Duty Cycle VFB < V
General Note: Devices are ESD protected; however, handling precautions are recommended.
Note 1: Measured using comparator trip point.
, ISW = 100mA 67 %
REF
= 100mA 15 V
= V
= V
= V
= V
= V
= V
SW
= V
= V
= V
, ISW = 100mA 2.85 V
OUT
, ISW = 100mA 3.30 V
OUT
, ISW = 100mA 5.00 V
OUT
= 100mA, Note 1 220 mV
SW
, ISW = 100mA 65 mV
OUT
, ISW = 100mA 75 mV
OUT
, ISW = 100mA 120 mV
OUT
OUT
OUT
OUT
0.9 V
220 mV
4.5 µA
4.5 µA
4.5 µA
4-78 1997
Page 4
MIC2571 Micrel
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)
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)
50
75
100
125
150
175
200
-60 -30 0 30 60 90 120 150
QUIESCENT CURRENT (µA)
TEMPERATURE (°C)
0
25
50
75
100
125
150
175
200
0246810
QUIESCENT CURRENT (µA)
SUPPLY VOLTAGE (V)
0
25
50
75
100
125
150
-60 -30 0 30 60 90 120 150
OUTPUT HYSTERESIS (mV)
TEMPERATURE (°C)
Typical Characteristics
Switch Saturation Voltage
1.0
TA = –40°C
0.8
0.6
0.4
0.2
SWITCH CURRENT (A)
0
0 0.2 0.4 0.6 0.8 1.0
SWITCH VOLTAGE (V)
1.4V
1.3V
1.2V
1.1V
VIN = 1.0V
Oscillator Frequency
vs. Temperature
30
VIN = 1.5V
I
= 100mA
SW
25
20
OSC. FREQUENCY (kHz)
15
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
Switch Saturation Voltage
1.4V
TA = 25°C
V
1.3V
1.2V
1.1V
1.0V
= 0.9V
Oscillator Duty Cycle
vs. Temperature
75
VIN = 1.5V
I
= 100mA
70
SW
65
60
DUTY CYCLE (%)
55
50
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
Switch Saturation Voltage
1.3V
1.4V
TA = 85°C
1.2V
1.1V
1.0V
VIN = 0.9V
Quiescent Current
vs. Temperature
VIN = 1.5V
4
Feedback Current
10
8
6
4
2
FEEDBACK CURRENT (µA)
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
Output Current Limit
1.75
1.50
1.25
1.00
1997 4-79
0.75
0.50
CURRENT LIMIT (A)
0.25
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
vs. Temperature
VIN = 1.5V
MIC2571-1
vs. Temperature
Feedback Current
vs. Temperature
50
VIN = 2.5V
40
MIC2571-2
30
20
10
FEEDBACK CURRENT (nA)
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
Switch Leakage Current
1000
100
0.1
0.01
SWITCH LEAKAGE CURRENT (nA)
vs. Temperature
10
1
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
Quiescent Current
vs. Supply Voltage
–40°C
+25°C
+85°C
Output Hysteresis
vs. Temperature
5V
3.3V
V
= 2.85V
OUT
Page 5
MIC2571 Micrel
Block Diagrams
V
V
BATT
BATT
IN
SYNC
MIC2571-1
Oscillator
0.22V
Reference
2.85V GND
3.3V5V
Driver
Selectable Voltage Version with External Components
IN
Oscillator
SYNC
MIC2571-2
SW
V
OUT
V
OUT
0.22V
Reference
Driver
FB
Adjustable Voltage Version with External Components
SW
GND
4-80 1997
Page 6
5V
0V
5V
0mA
I
PEAK
V
IN
Supply
Voltage
Inductor
Current
Output
Voltage
Time
MIC2571 Micrel
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 comparator 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
experiences
OUT
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 approximately 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 V
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
drops low enough to cause the
OUT
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.
1997 4-81
IN
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 frequency. 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 combinations 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
Inductor Current
V + V – V
OUT DIODE
≤
V + V – V
OUT DIODE SAT
Time
IN
Current “ratchet”
without current limit
Current Limit
Threshold
Continuous
Current
Discontinuous
Current
Figure 2. Current Limit Behavior
4
Page 7
MIC2571 Micrel
Figure 2 shows an example of inductor current in the continuous 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 conditions.
Inductors, Capacitors and Diodes
The importance of choosing correct inductors, capacitors and
diodes can not be ignored. Poor choices for these components can cause problems as severe as circuit failure or as
subtle as poorer than expected efficiency.
a.
b.
Inductor Current
c.
Time
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 electrolytic capacitors usually are the worst choice while tantalum
capacitors are typically better. Figure 4 demonstrates the
effect of capacitor ESR on output ripple voltage.
5.25
5.00
OUTPUT VOLTAGE (V)
4.75
0 500 1000 1500
TIME (µs)
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 saturates, 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 significantly 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 backwards 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.
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 rectification 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:
V
I =
t×
L
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
1IN
SAT
4-82 1997
Page 8
MIC2571 Micrel
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
. Therefore, when the
OUT
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 I1 = I2 to get:
V t = V t
××
11 2 2
1
2
=
t
2
t
1
V
V
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 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.
V I
×
Average I =
IN(max)
OUT OUT(max)
V Efficiency
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:
V
L =
L =
where t =
t1×
I
V
IN(min)
×
2 Average I
duty cycle
1
f
OSC
IN(max)
×
t
1
To illustrate the use of these equations a design example will
be given:
Assume:
MIC2571-1 (fixed oscillator)
V
= 5V
OUT
I
OUT(max)
V
IN(min)
=5mA
= 1.0V
efficiency = 75%.
×
Average I =
L =
IN(max)
1.0V 0.7
2 33.3mA 20kHz
××
5V 5mA
1.0V 0.75
×
×
= 33.3mA
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).
4
1997 4-83
Page 9
MIC2571 Micrel
Application Examples
1V to 1.5V
1 Cell
1V to 1.5V
1 Cell
D1
MBR0530
1
4
C1*
47µF
16V
8
IN
MIC2571
SYNC
7
L1
150µH
SW
5V
GND
2
* Needed if battery is more than 4" away from MIC2571
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
Example 1. 5V/5mA Regulator
L1
150µH
8
C1*
47µF
16V
IN
MIC2571
SYNC
SW
3.3V
GND
7
2
* Needed if battery is more than 4" away from MIC2571
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
D1
MBR0530
1
5
V
OUT
5V/5mA
C2
47µF
16V
V
OUT
3.3V/8mA
C2
47µF
16V
1.0V to 1.5V
1 Cell
Example 2. 3.3V/8mA Regulator
1
6
D1
MBR0530
R2
1M
1%
R1
20k
1%
L1
150µH
8
C1*
47µF
16V
IN
MIC2571
SYNC
SW
FB
GND
7
2
* Needed if battery is more than 4" away from MIC2571
V
= 0.22V (1 + R2/R1)
OUT
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
Example 3. 12V/40mA Regulator
V
12V/2mA
C2
15µF
25V
OUT
4-84 1997
Page 10
MIC2571 Micrel
L1
150µH
8
1V to 1.5V
1 Cell
C1*
47µF
16V
IN
MIC2571
SYNC
7
GND
SW
5V
2
MBR0530
* Needed if battery is more than 4" away from MIC2571
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
Example 4. ±5V/2mA Regulator
1V to 1.5V
1 Cell
C1
100µF
10V
Minimum Start-Up Supply Voltage
V
= 1V, I
IN
VIN = 1.2V, I
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
LOAD
LOAD
R1
51k
= 0A
= 15mA
IN
MIC2571
SYNC
1
4
D2
MBR0530
Q1
2N3906
8
GND
7
L1
47µH
2
D3
SW
5V
C3
47µF
16V
D1
MBR0530
220k
MBRA140
1
4
R1
D1
C4
47µF
16V
47µF
V
5V/15mA
C2
100µF
10V
V
C2
16V
–V
–I
OUT
/+I
OUT
OUT
5V/2mA
/–I
OUT
–5V/2mA
≤ +I
OUT
OUT
OUT
4
Example 5. 5V/15mA Regulator
8
IN
MIC2571
GND
7
L1
150µH
2
SW
FB
MBR0530
1
6
MBR0530
D1
D2
1V to 1.5V
1 Cell
C1
47µF
16V
–V
= – 0.22V *(1+R2/R1) + 0.6V
OUT
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
SYNC
Example 6. –12V/2mA Regulator
D3
1N4148
C1
15µF
25V
R3
220k
R2
1.1MEG
1.1%
R1
20k
1%
C2
15µF
25V
C2
0.1µF
–12V/2mA
–V
OUT
1997 4-85
Page 11
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
Evaluation Board Layout
Component Side and Silk Screen (Not Actual Size)
Solder Side and Silk Screen (Not Actual Size)
4-86 1997
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