Microchip MCP1661T-E/MNY High-voltage integrated switch pwm boost regulator with uvlo Datasheet

MCP1661
High-Voltage Integrated Switch PWM Boost Regulator with UVLO
Features
General Description
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The MCP1661 device is a compact, high-efficiency,
fixed-frequency, non-synchronous step-up DC-DC
converter which integrates a 36V, 800 m NMOS
switch. It provides a space-efficient high-voltage
step-up power supply solution for applications powered
by either two-cell or three-cell alkaline, Ultimate Lithium,
NiCd, NiMH, one-cell Li-Ion or Li-Polymer batteries.
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36V, 800 m Integrated Switch
Up to 92% Efficiency
High Output Voltage Range: up to 32V
1.3A Peak Input Current Limit:
- IOUT > 200 mA @ 5.0V VIN, 12V VOUT
- IOUT > 125 mA @ 3.3V VIN, 12V VOUT
- IOUT > 100 mA @ 4.2V VIN, 24V VOUT
Input Voltage Range: 2.4V to 5.5V
Undervoltage Lockout (UVLO):
- UVLO @ VIN Rising: 2.3V, typical
- UVLO @ VIN Falling: 1.85V, typical
No Load Input Current: 250 µA, typical
Sleep mode with 200 nA Typical Quiescent
Current
PWM Operation with Skip mode: 500 kHz
Feedback Voltage Reference: VFB = 1.227V
Cycle-by-Cycle Current Limiting
Internal Compensation
Inrush Current Limiting and Internal Soft Start
Output Overvoltage Protection (OVP) in the event
of:
- Feedback pin shorted to GND
- Disconnected feedback divider
Overtemperature Protection
Easily Configurable for SEPIC or Flyback
Topologies
Available Packages:
- 5-Lead SOT-23
- 8-Lead 2x3 TDFN
Applications
• Two and Three-Cell Alkaline, Lithium Ultimate and
NiMH/NiCd Portable Products
• Single-Cell Li-Ion to 5V, 12V or 24V Converters
• LCD Bias Supply for Portable Applications
• Camera Phone Flash
• Portable Medical Equipment
• Hand-Held Instruments
• Single-Cell Li-Ion to 3.0V or 3.3V SEPIC
Applications (see Figure 6-3)
The integrated switch is protected by the 1.3A
cycle-by-cycle inductor peak current limit operation.
There is an output overvoltage protection which turns
off switching in case the feedback resistors are
accidentally disconnected or the feedback pin is
short-circuited to GND.
Low-voltage technology allows the regulator to start-up
without high inrush current or output voltage overshoot
from a low-voltage input. The device features a UVLO
which avoids start-up and operation with low inputs or
discharged batteries for two cell-powered applications.
For standby applications (EN = GND), the device stops
switching, enters Sleep mode and consumes 200 nA
(typical) of input current.
MCP1661 is easy to use and allows creating classic
boost, SEPIC or flyback DC-DC converters within a
small Printed Circuit Board (PCB) area. All
compensation and protection circuitry is integrated to
minimize the number of external components. Ceramic
input and output capacitors are used.
Package Types
MCP1661
SOT-23
SW 1
5 VIN
GND 2
VFB 3
4 EN
MCP1661
2x3 TDFN*
VFB 1
SGND 2
SW 3
NC 4
8 EN
EP
9
7 PGND
6 NC
5 VIN
* Includes Exposed Thermal Pad (EP); see Table 3-1.
 2014-2015 Microchip Technology Inc.
DS20005315B-page 1
MCP1661
Typical Applications
D
PMEG2005
L
4.7 μH
C IN
4.7-10 μF
V IN
2.4V -3.0V
SW
V IN
R TOP
1.05 M Ω
MCP1661
V FB
ALKALINE
+
EN
-
C OUT
4.7-10 μF
R BOT
120 k Ω
GND
ON
VFB = 1.227V
OFF
ALKALINE
+
V OUT
12V, 75 mA-125 mA
-
D
MBR0540
L
10 μH
C IN
10 μF
V IN
3.0V - 4.2V
V OUT
24V, 50 mA-125 mA
SW
V IN
R TOP
1.05 MΩ
MCP1661
V FB
ALKALINE
+
EN
-
C OUT
10 μF
R BOT
56 k Ω
GND
ALKALINE
+
-
300
VOUT = 12V
IOUT (mA)
250
200
150
VOUT = 24V
100
50
0
2.4
2.8
3.2
3.6
VIN (V)
4
4.4
4.8
Maximum Output Current vs. VIN
DS20005315B-page 2
 2014-2015 Microchip Technology Inc.
MCP1661
1.0
ELECTRICAL
CHARACTERISTICS
Absolute Maximum Ratings †
VSW – GND .....................................................................+36V
EN, VIN – GND...............................................................+6.0V
VFB .................................................................................+1.3V
Power Dissipation ....................................... Internally Limited
Storage Temperature .................................... -65°C to +150°C
Ambient Temperature with Power Applied .... -40°C to +125°C
Operating Junction Temperature................... -40°C to +150°C
ESD Protection On All Pins:
HBM ................................................................. 4 kV
MM ..................................................................300V
† Notice: Stresses above those listed under “Maximum
Ratings” may cause permanent damage to the device.
This is a stress rating only and functional operation of
the device at those or any other conditions above those
indicated in the operational sections of this
specification is not intended. Exposure to maximum
rating conditions for extended periods may affect
device reliability.
DC AND AC CHARACTERISTICS
Electrical Specifications: Unless otherwise specified, all limits apply for typical values at ambient temperature
TA = +25°C, VIN = 3.3V, IOUT = 20 mA, VOUT = 12V, CIN = COUT = 10 µF, X7R ceramic, L = 4.7 µH.
Boldface specifications apply over the controlled TA range of -40°C to +125°C.
Parameters
Sym.
Min.
Typ.
Max.
Units
VIN
2.4
—
5.5
V
Note 1
UVLOSTART
—
2.3
—
V
VIN rising,
IOUT = 1 mA resistive load
UVLOSTOP
—
1.85
—
V
VIN falling,
IOUT = 1 mA resistive load
Output Voltage Adjust Range
VOUT
—
—
32
V
Note 1
Maximum Output Current
IOUT
—
125
—
mA
3.3V VIN, 12V VOUT
200
—
mA
5.0V VIN, 12V VOUT
100
—
mA
4.2V VIN, 24V VOUT
1.227
1.264
V
Input Voltage Range
Undervoltage Lockout
(UVLO)
Feedback Voltage
Conditions
VFB
1.190
-3
—
3
%
Feedback Input Bias Current
IVFB
—
0.005
—
µA
No Load Input Current
IIN0
—
250
—
µA
Device switching, no load,
3.3V VIN, 12V VOUT (Note 2)
Shutdown Quiescent Current
IQSHDN
—
200
—
nA
EN = GND,
feedback divider current not
included (Note 3)
Peak Switch Current Limit
IN(MAX)
—
1.3
—
A
Note 4
INLK
—
0.4
—
µA
VIN = VSW = 5V; VOUT = 5.5V
VEN = VFB = GND
RDS(ON)
—
0.8
—

VIN = 5V, VOUT = 12V,
IOUT = 100 mA (Note 4)
VFB Accuracy
NMOS Switch Leakage
NMOS Switch ON Resistance
Note 1:
2:
3:
4:
Minimum input voltage in the range of VIN (VIN < 5.5V < VOUT) depends on the maximum duty cycle
(DCMAX) and on the output voltage (VOUT), according to the boost converter equation:
VINmin = VOUT x (1 – DCMAX).
IIN0 varies with input and output voltage (Figure 2-8). IIN0 is measured on the VIN pin when the device is
switching (EN = VIN), at no load, with RTOP = 120 k and RBOT = 1.05 M.
IQSHDN is measured on the VIN pin when the device is not switching (EN = GND), at no load, with the
feedback resistors (RTOP + RBOT) disconnected from VOUT.
Determined by characterization, not production tested.
 2014-2015 Microchip Technology Inc.
DS20005315B-page 3
MCP1661
DC AND AC CHARACTERISTICS (CONTINUED)
Electrical Specifications: Unless otherwise specified, all limits apply for typical values at ambient temperature
TA = +25°C, VIN = 3.3V, IOUT = 20 mA, VOUT = 12V, CIN = COUT = 10 µF, X7R ceramic, L = 4.7 µH.
Boldface specifications apply over the controlled TA range of -40°C to +125°C.
Parameters
Sym.
Min.
Typ.
Max.
Units
Conditions
Line Regulation
|(VFB/VFB)/
VIN|
—
0.05
0.5
%/V
VIN = 3V to 5V,
IOUT = 20 mA, VOUT = 12.0V
Load Regulation
|VFB/VFB|
—
0.5
1.5
%
Overvoltage Reference
OVP_REF
—
80
—
mV
IOUT = 20 mA to 100 mA,
VIN = 3.3V, VOUT = 12.0V
VFB to GND transition
(Note 4)
Maximum Duty Cycle
DCMAX
88
90
—
%
Note 4
Switching Frequency
fSW
425
500
575
kHz
±15%
EN Input Logic High
VIH
85
—
—
% of VIN IOUT = 1 mA
EN Input Logic Low
VIL
—
—
7.5
IENLK
—
0.025
—
% of VIN IOUT = 1 mA
µA
VEN = 5V
Soft-Start Time
tSS
—
3
—
ms
Thermal Shutdown
Die Temperature
TSD
—
150
—
°C
TSDHYS
—
15
—
°C
EN Input Leakage Current
Die Temperature Hysteresis
Note 1:
2:
3:
4:
TA, EN Low-to-High,
90% of VOUT
Minimum input voltage in the range of VIN (VIN < 5.5V < VOUT) depends on the maximum duty cycle
(DCMAX) and on the output voltage (VOUT), according to the boost converter equation:
VINmin = VOUT x (1 – DCMAX).
IIN0 varies with input and output voltage (Figure 2-8). IIN0 is measured on the VIN pin when the device is
switching (EN = VIN), at no load, with RTOP = 120 k and RBOT = 1.05 M.
IQSHDN is measured on the VIN pin when the device is not switching (EN = GND), at no load, with the
feedback resistors (RTOP + RBOT) disconnected from VOUT.
Determined by characterization, not production tested.
TEMPERATURE SPECIFICATIONS
Electrical Specifications: Unless otherwise specified, all limits apply for typical values at ambient temperature
TA = +25°C, VIN = 3.3V, IOUT = 20 mA, VOUT = 12V, CIN = COUT = 10 µF, X7R ceramic, L = 4.7 µH and 5-lead
SOT-23 package.
Boldface specifications apply over the controlled TA range of -40°C to +125°C.
Parameters
Sym.
Min.
Typ.
Max.
Units
Operating Junction Temperature
Range
TJ
-40
—
+125
°C
Storage Temperature Range
TA
-65
—
+150
°C
Maximum Junction Temperature
TJ
—
—
+150
°C
Thermal Resistance, 5LD-SOT-23
JA
—
201.0
—
°C/W
Thermal Resistance, 8LD-2x3 TDFN
JA
—
52.5
—
°C/W
Conditions
Temperature Ranges
Steady State
Transient
Package Thermal Resistances
DS20005315B-page 4
 2014-2015 Microchip Technology Inc.
MCP1661
2.0
TYPICAL PERFORMANCE CURVES
Note:
The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
Note: Unless otherwise indicated, VIN = 3.3V, IOUT = 20 mA, VOUT = 12V, CIN = COUT = 10 µF, X7R ceramic,
L = 4.7 µH, TA = 25°C, 5-lead SOT-23 package.
100
UVLO Start
90
2.2
Efficiency (%)
UVLO Thresholds (V)
2.3
2.1
2
1.9
UVLO Stop
VOUT = 9.0V
L = 4.7 μH
VIN = 5.5V
80
VIN = 2.3V
70
VIN = 3.0V VIN = 4.0V
60
50
40
1.8
30
1.7
20
-40 -25 -10
5 20 35 50 65 80 95 110 125
Ambient Temperature (°C)
0.1
FIGURE 2-4:
IOUT.
FIGURE 2-1:
Undervoltage Lockout
(UVLO) vs. Ambient Temperature.
100
90
1.225
Efficiency (%)
Feedback Voltage (V)
1.230
1.220
10
IOUT (mA)
100
1000
9.0V VOUT Efficiency vs.
VOUT = 12.0V
L = 4.7 μH
VIN = 4.0V
VIN = 5.5V
80
70
VIN = 2.3V
VIN = 3.0V
60
50
40
1.215
30
20
1.210
-40 -25 -10
0.1
5 20 35 50 65 80 95 110 125
Ambient Temperature (°C)
FIGURE 2-2:
VFB Voltage vs. Ambient
Temperature and VIN.
900
1
10
IOUT (mA)
100
1000
12.0V VOUT Efficiency vs.
FIGURE 2-5:
IOUT.
100
1000
L = 4.7 μH, VOUT = 6V, 9V and 12V
L = 10 μH, VOUT = 24V
90
Efficiency (%)
800
700
IOUT (mA)
1
600
VOUT = 6.0V
500
400
VOUT = 9.0V
300
VOUT = 12V
VOUT = 24.0V
VIN = 5.5V
L = 10 μH
80
70
VIN = 3.0V
VIN = 4.0V
60
50
40
200
30
100
VOUT = 24V
0
2.3
2.7
FIGURE 2-3:
vs. VIN.
3.1
3.5
3.9 4.3
VIN (V)
4.7
5.1
5.5
Maximum Output Current
 2014-2015 Microchip Technology Inc.
20
0.1
FIGURE 2-6:
IOUT.
1
10
IOUT (mA)
100
1000
24.0V VOUT Efficiency vs.
DS20005315B-page 5
MCP1661
Note: Unless otherwise indicated, VIN = 3.3V, IOUT = 20 mA, VOUT = 12V, CIN = COUT = 10 µF, X7R ceramic,
L = 4.7 µH, TA = 25°C, 5-lead SOT-23 package.
IIN0 No Load Input Current (μA)
Inductor Peak Current (A)
1.5
1.3
1.1
0.9
VIN = 5.0V
VOUT = 12.0V
0.7
0.5
-40 -25 -10
1800
1200
1000
600
400
200
225
VOUT = 6.0V
200
175
5
20 35 50 65 80 95 110 125
FIGURE 2-10:
No Load Input Current, IIN0
vs. Ambient Temperature.
550
VIN = 3.0V
IOUT = 100 mA
525
500
475
450
425
150
2.3
2.7
3.1
3.5 3.9 4.3
Input Voltage (V)
4.7
5.1
-40 -25 -10
5.5
FIGURE 2-8:
No Load Input Current, IIN0
vs. VIN (EN = VIN).
5 20 35 50 65 80 95 110 125
Ambient Temperature (°C)
FIGURE 2-11:
Temperature.
fSW vs. Ambient
6
0.30
Note: Without FB Resistor Divider Current
0.25
5
0.20
4
VIN (V)
IQ Shutdown Mode (μA)
VIN = 5.5V
0
Ambient Temperature (°C)
Switching Frequency (kHz)
VOUT = 12.0V
VIN= 3.0V
800
575
250
VIN = 2.3V
1400
-40 -25 -10
300
275
VOUT = 12V
1600
5 20 35 50 65 80 95 110 125
Ambient Temperature (°C)
FIGURE 2-7:
Inductor Peak Current Limit
vs. Ambient Temperature.
IIN0 No Load Input Current (μA)
2000
0.15
VOUT = 24.0V
VOUT = 12.0V
VOUT = 6.0V
3
0.10
2
0.05
1
0
0.00
1.8
2.2
2.6
3
3.4 3.8
Input Voltage (V)
4.2
4.6
FIGURE 2-9:
Shutdown Quiescent
Current, IQSHDN vs. VIN (EN = GND).
DS20005315B-page 6
5
0
5
FIGURE 2-12:
Threshold.
10
15
20
IOUT (mA)
25
30
PWM Pulse Skipping Mode
 2014-2015 Microchip Technology Inc.
MCP1661
Note: Unless otherwise indicated, VIN = 3.3V, IOUT = 20 mA, VOUT = 12V, CIN = COUT = 10 µF, X7R ceramic,
L = 4.7 µH, TA = 25°C, 5-lead SOT-23 package.
VOUT
50 mV/div, AC Coupled
20 MHz BW
Enable Thresholds (% of VIN)
100
IOUT = 1 mA
90
EN VIH
80
VSW
5 V/div
70
60
50
40
30
20
EN VIL
10
0
2.3
2.6
2.9
FIGURE 2-13:
Voltage.
3.2 3.5 3.8 4.1
Input Voltage (V)
4.4
4.7
IL
400 mA/div
5
1 µs/div
Enable Threshold vs. Input
FIGURE 2-16:
Waveforms.
High Load PWM Mode
IOUT = 15 mA
1
Switch RDS(ON) (Ω)
IOUT = 100 mA
IOUT = 100 mA
0.8
VOUT
3 V/div
0.6
VIN
3 V/div
0.4
IL
300 mA/div
0.2
0
2.6
2.9
3.2
FIGURE 2-14:
vs. VIN.
3.5
3.8
4.1
Input Voltage (V)
4.4
4.7
5
VEN
3 V/div
500 µs/div
N-Channel Switch RDSON
FIGURE 2-17:
12.0V Start-Up by Enable.
IOUT = 15 mA
IOUT = 5 mA
VOUT
20 mV/div, AC Coupled
20 MHz BW
VSW
5 V/div
VOUT
3 V/div
VIN
3 V/div
IL
100 mA/div
VSW
5 V/div
2 µs/div
FIGURE 2-15:
12.0V VOUT Light Load
PWM Mode Waveforms.
 2014-2015 Microchip Technology Inc.
500 µs/div
FIGURE 2-18:
(VIN = VENABLE).
12.0V Start-Up
DS20005315B-page 7
MCP1661
Note: Unless otherwise indicated, VIN = 3.3V, IOUT = 20 mA, VOUT = 12V, CIN = COUT = 10 µF, X7R ceramic,
L = 4.7 µH, TA = 25°C, 5-lead SOT-23 package.
VOUT
200 mV/div, AC Coupled
Step from 20 mA to 50 mA
IOUT
30 mA/div
2 ms/div
FIGURE 2-19:
Waveforms.
12.0V VOUT Load Transient
IOUT = 60 mA
VOUT
100 mV/div, AC Coupled
Step from 3.3V to 5.0V
VIN
1 V/div
1 ms/div
FIGURE 2-20:
Waveforms.
DS20005315B-page 8
12.0V VOUT Line Transient
 2014-2015 Microchip Technology Inc.
MCP1661
3.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1:
3.1
PIN FUNCTION TABLE
MCP1661
SOT-23
MCP1661
2x3 TDFN
3
1
VFB
—
2
SGND
Symbol
Description
Feedback Voltage Pin
Signal Ground Pin (TDFN only)
1
3
SW
Switch Node, Boost Inductor Input Pin
—
4, 6
NC
Not Connected
Input Voltage Pin
5
5
VIN
—
7
PGND
Power Ground Pin (TDFN only)
4
8
EN
Enable Control Input Pin
—
9
EP
Exposed Thermal Pad (EP); must be connected to Ground.
(TDFN only)
2
—
GND
Ground Pin (SOT-23 only)
Feedback Voltage Pin (VFB)
The VFB pin is used to provide output voltage regulation
by using a resistor divider. The VFB voltage is 1.227V
typical.
3.2
Signal Ground Pin (SGND)
The signal ground pin is used as a return for the
integrated reference voltage and error amplifier. The
signal ground and power ground must be connected
externally in one point.
3.3
Switch Node Pin (SW)
Connect the inductor from the input voltage to the SW
pin. The SW pin carries inductor current, which can be
as high as 1.3A peak. The integrated N-Channel switch
drain is internally connected to the SW node.
3.4
Not Connected (NC)
3.7
Enable Pin (EN)
The EN pin is a logic-level input used to enable or
disable device switching and lower quiescent current
while disabled. A logic high (>85% of VIN) will enable
the regulator output. A logic low (<7.5% of VIN) will
ensure that the regulator is disabled.
3.8
Exposed Thermal Pad (EP)
There is no internal electrical connection between the
Exposed Thermal Pad (EP) and the SGND and PGND
pins. They must be connected to the same potential on
the PCB.
3.9
Ground Pin (GND)
The ground or return pin is used for circuit ground
connection. The length of the trace from the input cap
return, the output cap return and the GND pin must be
as short as possible to minimize noise on the GND pin.
The 5-lead SOT-23 package uses a single ground pin.
This is an unconnected pin.
3.5
Power Supply Input Voltage Pin
(VIN)
Connect the input voltage source to VIN. The input
source must be decoupled from GND with a 4.7 µF
minimum capacitor.
3.6
Power Ground Pin (PGND)
The power ground pin is used as a return for the
high-current N-Channel switch. The signal ground and
power ground must be connected externally in one
point.
 2014-2015 Microchip Technology Inc.
DS20005315B-page 9
MCP1661
NOTES:
DS20005315B-page 10
 2014-2015 Microchip Technology Inc.
MCP1661
4.0
DETAILED DESCRIPTION
4.1
Device Overview
MCP1661 is a constant frequency PWM boost (step-up)
converter, based on a peak current mode architecture
which delivers high efficiency over a wide load range
from two-cell and three-cell Alkaline, Ultimate Lithium,
NiMH, NiCd and single-cell Li-Ion battery inputs. A high
level of integration lowers total system cost, eases
implementation and reduces board area.
The device features controlled start-up voltage
(UVLO), adjustable output voltage, 500 kHz PWM
operation with Skipping mode, 36V integrated switch,
internal compensation, inrush current limit, soft start,
and overvoltage protection in case the VFB connection
is lost.
The 800 m, 36V integrated switch is protected by the
1.3A cycle-by-cycle inductor peak current operation.
When the Enable pin is pulled to ground (EN = GND),
the device stops switching, enters in Shutdown mode
and consumes approximately 200 nA of input current
(the feedback current is not included).
MCP1661 can be used to build classic boost, SEPIC or
flyback DC-DC converters.
 2014-2015 Microchip Technology Inc.
DS20005315B-page 11
MCP1661
4.2
Functional Description
Figure 4-1 depicts the functional block diagram of the
MCP1661 device. It incorporates a current mode
control scheme, in which the PWM ramp signal is
derived from the NMOS power switch current
(VSENSE). This ramp signal adds slope ramp
compensation signal (VRAMP) and is compared to the
output of the error amplifier (VERROR) to control the
on-time of the power switch. A proper slope rate will be
designed to improve circuit stability.
The MCP1661 device is a compact, high-efficiency,
fixed-frequency, step-up DC-DC converter that
provides an easy-to-use high-output power supply
solution for applications powered by either two-cell or
three-cell alkaline or Lithium Energizer, three-cell NiCd
or NiMH or one-cell Li-Ion or Li-Polymer batteries.
SW
Internal Bias
and UVLO
Comparator
V IN
V BIAS
V UVLO_REF
V IN_OK
Gate Drive
and
Shutdown
Control
Logic
EN
Overcurrent Comparator
V LIMIT
+
V EXT
V SENSE
+
-
V RAMP
Slope
Compensation
Oscillator
S
GND
CLK
V PWM
+
-
Logic
SR Latch
QN
V ERROR
EA
1.227V
V FB
+
Overvoltage Comparator
OVP_REF
V FB
Rc
1.227V
Cc OVP_REF
V UVLO_REF
+
-
V FB_FAULT
V OUT_OK
Power Good
Comparator
and Delay
Thermal
Shutdown
FIGURE 4-1:
DS20005315B-page 12
V FB
V IN_OK
Band Gap
EN
MCP1661 Simplified Block Diagram.
 2014-2015 Microchip Technology Inc.
MCP1661
4.2.1
INTERNAL BIAS
The MCP1661 device gets its bias from VIN. The VIN
bias is used to power the device and drive circuits over
the entire operating range.
4.2.2
START-UP VOLTAGE
AND SOFT START
The MCP1661 device starts at input voltages that are
higher than or equal to a predefined set UVLO value.
MCP1661 starts switching at approximately 2.3V for
12.0V output and 1 mA resistive load. Once started, the
device will continue to operate under normal load
conditions down to 1.85V typical. There is a soft start
feature which provides a way to limit the inrush current
drawn from the input (batteries) during start-up. The
soft start has an important role in applications where
the switch will reach 32V. During start-up, excessively
high switch current, together with the presence of high
voltage, can overstress the NMOS switch.
When the device is powered (EN = VIN and VIN rises
from zero to its nominal value), the output capacitor
charges to a value close to the input voltage (or VIN
minus a Schottky diode voltage drop). The overshoot
on output is limited by slowly increasing the reference
of the error amplifier. There is an internal reference
voltage which charges an internal capacitor with a
weak current source. The voltage on this capacitor
slowly ramps the reference voltage. The soft-start
capacitor is completely discharged in the event of a
commanded shutdown or a thermal shutdown.
Due to the direct path from input to output, in the case
of start-up by enable (EN voltage switches from low-tohigh), the output capacitor is already charged and the
output starts from a value close to the input voltage.
The internal oscillator has a delayed start to let the
output capacitor be completely charged to the input
voltage value.
4.2.3
UNDERVOLTAGE LOCKOUT
(UVLO)
MCP1661 features an UVLO which prevents fault
operation below 1.85V, which corresponds to the
typical value of two discharged batteries. The device
starts its normal operation at 2.3V input. The upper limit
is set to avoid any input transients (temporary VIN
drop), which might trigger the lower UVLO threshold
and restart the device. Usually, these voltage transients
(overshoots and undershoots) have up to a few
hundred mV.
MCP1661 is a non-synchronous boost regulator. Due
to this fact, there is a direct path from VIN to VOUT
through the inductor and the diode. This means that,
while the device is not switching (VIN below UVLOSTOP
threshold), VOUT is not zero but equal to VIN – VF
(where VF is the voltage drop on the rectifier diode).
 2014-2015 Microchip Technology Inc.
When the input voltage is below the 2.3V UVLO start
threshold, the device is operating with limited
specification.
4.2.4
PWM MODE OPERATION
MCP1661
operates
as
a
fixed-frequency,
non-synchronous converter. The switching frequency
is maintained at 500 kHz with a precision oscillator.
Lossless current sensing converts the peak current
signal to a voltage (VSENSE) and adds it to the internal
slope compensation (VRAMP). This summed signal is
compared to the voltage error amplifier output (VERROR)
to provide a peak current control signal (VPWM) for the
PWM control block. The slope compensation signal
depends on the input voltage. Therefore, the converter
provides the proper amount of slope compensation to
ensure stability. The peak current is set to 1.3A.
The MCP1661 device will operate in PWM even during
periods of light load operation by skipping pulses. By
operating in PWM mode, the output ripple is low and
the frequency is constant.
4.2.5
ADJUSTABLE OUTPUT VOLTAGE
The MCP1661 output voltage is adjustable with a
resistor divider over the VOUT range. High value
resistors are recommended to minimize power loss and
keep efficiency high at light loads. The device
integrates a transconductance-type error amplifier and
the values of the feedback resistors do not influence
the stability of the system.
4.2.6
MINIMUM INPUT VOLTAGE
AND MAXIMUM OUTPUT CURRENT
The maximum output current for which the device can
supply the load is dependent upon the input and output
voltage. The minimum input voltage necessary to reach
the value of the desired output depends on the
maximum duty cycle (approximately 90%) in
accordance
with
the
mathematical
relation
VOUT = VINmin/(1 – DMAX). As there is a 1.3A inductor
peak current limit, VOUT can go out of regulation before
reaching the maximum duty cycle. (For boost
converters, the average inductor current is equal to the
input current.)
For example, to ensure a 100 mA load current for
VOUT = 12.0V, a minimum of 2.8V input voltage is
necessary. If an application is powered by one Li-Ion
battery (VIN from 3.3V to 4.2V), the minimum load
current the MCP1661 device can deliver is close to
50 mA at 24.0V output (see Figure 2-3).
DS20005315B-page 13
MCP1661
4.2.7
ENABLE PIN
The MCP1661 device is enabled when the EN pin is set
high. The device is put into Shutdown mode when the
EN pin is set low. To enable the boost converter, the EN
voltage level must be greater than 85% of the VIN
voltage. To disable the boost converter, the EN voltage
must be less than 7.5% of the VIN voltage.
In Shutdown mode, the MCP1661 device stops
switching and all internal control circuitry is switched
off. On boost configuration, the input voltage will be
bypassed to output through the inductor and the
Schottky diode. In the SEPIC converter, Shutdown
mode acts as output disconnect.
4.2.8
INTERNAL COMPENSATION
The error amplifier, with its associated compensation
network, completes the closed-loop system by
comparing the output voltage to a reference at the
input of the error amplifier and by feeding the amplified
and inverted error voltage to the control input of the
inner current loop. The compensation network
provides phase leads and lags at appropriate
frequencies to cancel excessive phase lags and leads
of the power circuit. All necessary compensation
components and slope compensation are integrated.
4.2.9
OUTPUT OVERVOLTAGE
PROTECTION (OVP)
An internal VFB fault signal turns off the PWM signal
(VEXT) and prevents the output from going out of
regulation in the event of:
4.2.10
OVERCURRENT LIMIT
The MCP1661 device uses a 1.3A cycle-by-cycle
inductor peak current limit to protect the N-channel
switch. There is an overcurrent comparator which
resets the drive latch when the peak of the inductor
current reaches the limit. In current limitation, the
output voltage starts dropping.
4.2.11
OUTPUT SHORT CIRCUIT
CONDITION
Like all non-synchronous boost converters, the MCP1661
inductor current will increase excessively during a short
circuit on the converter’s output. Short circuit on the
output will cause the diode rectifier to fail and the
inductor’s temperature to rise. When the diode fails, the
SW pin becomes a high-impedance node, it remains
connected only to the inductor and the excessive resulted
ringing will damage the MCP1661 device.
4.2.12
OVERTEMPERATURE
PROTECTION
Overtemperature protection circuitry is integrated into
the MCP1661 device. This circuitry monitors the device
junction temperature and shuts the device off if the
junction temperature exceeds the typical +150°C
threshold. If this threshold is exceeded, the device will
automatically restart when the junction temperature
drops by 15°C. The output overvoltage protection
(OVP) is reset during an overtemperature condition.
• short circuit of the feedback pin to GND
• disconnection of the feedback divider from VOUT
In any of the above events, for a regular integrated
boost circuit (IC) without any protection implemented, if
the VFB voltage drops to ground potential, its N-channel
transistor will be forced to switch at full duty cycle and
VOUT rises. This Fault event may cause the SW pin to
exceed its maximum voltage rating and may damage
the boost regulator IC, the external components and
the load. To avoid all these, MCP1661 has
implemented an overvoltage protection (OVP) which
turns off PWM switching when an overvoltage condition
is detected. There is an overvoltage comparator with
80 mV reference which monitors the VFB voltage.
The OVP comparator is disabled during start-up
sequences and thermal shutdown.
If OVP occurs with the input voltage below the
UVLOSTART threshold and VFB remains under 80 mV
due to a low input voltage or overload condition, the
device latches its output and resumes after restart.
DS20005315B-page 14
 2014-2015 Microchip Technology Inc.
MCP1661
5.0
APPLICATION INFORMATION
5.1
Typical Applications
The MCP1661 nonsynchronous boost regulator
operates over a wide output voltage range up to 32V.
The input voltage ranges from 2.4V to 5.5V. The device
operates down to 1.85V input with limited specification.
The UVLO thresholds are set to 2.3V when VIN is
ramping and to 1.85V when VIN is falling. The power
efficiency conversion is high for several decades of
load range. Output current capability increases with the
input voltage and decreases with the increasing output
voltage. The maximum output current is based on the
N-channel switch peak current limit, set to 1.3A, and on
a maximum duty cycle of 90%. Typical characterization
curves in this data sheet are presented to display the
typical output current capability.
5.2
Adjustable Output Voltage
Calculations
To calculate the resistor divider values for the
MCP1661, the following equation can be used. Where
RTOP is connected to VOUT, RBOT is connected to GND
and both are connected to the VFB input pin.
The values of the two resistors, RTOP and RBOT, affect
the no load input current and quiescent current. In
Shutdown mode (EN = GND), the device consumes
approximately 0.2 µA. With 24V output and 1 M
feedback divider, the current which this divider drains
from input is 2.4 µA. This value is much higher than what
the device consumes. Keeping RTOP and RBOT high will
optimize efficiency conversion at very light loads. There
are some potential issues with higher value resistors, as
in the case of small surface mount resistors;
environment contamination can create leakage paths on
the PCB that significantly change the resistor divider and
may affect the output voltage tolerance.
5.2.1
OVERVOLTAGE PROTECTION
The MCP1661 features an output overvoltage
protection (OVP) in case RTOP is disconnected from
the VOUT line. A typical 80 mV OVP reference is
compared to VFB voltage. If voltage on the VFB pin
drops below the reference value, the device stops
switching and prevents VOUT from rising up to a
dangerous value.
OVP is not enabled during start-up and thermal
shutdown events.
EQUATION 5-1:
V OUT
R TOP = R BOT   ------------- – 1
 V FB

EXAMPLE 5-1:
VOUT = 12.0V
VFB
= 1.227V
RBOT = 120 k
RTOP = 1053.6 k (VOUT = 11.96V with a standard
value of 1050 k)
EXAMPLE 5-2:
VOUT = 24.0V
VFB
= 1.227V
RBOT = 53 k
RTOP = 983.67 k (VOUT = 23.82V with a standard
value of 976 k)
 2014-2015 Microchip Technology Inc.
DS20005315B-page 15
MCP1661
5.3
Input Capacitor Selection
The boost input current is smoothened by the boost
inductor, reducing the amount of filtering necessary at
the input. Some capacitance is recommended to
provide decoupling from the input source. Because
MCP1661 is rated to work up to 125°C, low ESR X7R
ceramic capacitors are well suited, since they have a
low temperature coefficient and are small-sized. For
limited temperature range use at up to 85°C, a X5R
ceramic capacitor can be used. For light load
applications, 4.7 µF of capacitance is sufficient at the
input. For high-power applications that have high
source impedance or long leads, using a 20-30 µF
input capacitor is recommended to sustain high input
boost currents. Additional input capacitance can be
added to provide a stable input voltage.
Table 5-1 contains the recommended range for the
input capacitor value.
5.4
Output Capacitor Selection
The output capacitor helps provide a stable output
voltage during sudden load transients and reduces
the output voltage ripple. As with the input capacitor,
X7R ceramic capacitor is recommended for this
application. Using other capacitor types (aluminum or
tantalum) with large ESR has impact on the
converter's efficiency (see AN1337), maximum output
power and stability. For limited temperature range (up
to 85°C), X5R ceramic capacitors can be used. The
DC rating of the output capacitor should be greater
than the VOUT value. Generally, ceramic capacitors
lose up to 50% of their capacity when the voltage
applied is close to the maximum DC rating. Choosing
a capacitor with a safe higher DC rating or placing two
capacitors in parallel assure enough capacity to
correctly filter the output voltage.
internal architecture which minimize the ESL. Consult
the ceramic capacitor's manufacturer portfolio for
more information.
Table 5-1 contains the recommended range for the
input and output capacitor value.
TABLE 5-1:
CAPACITOR VALUE RANGE
CIN
COUT
Minimum
4.7 µF
10 µF
Maximum
—
47 µF
5.5
Inductor Selection
The MCP1661 device is designed to be used with small
surface mount inductors; the inductance value can
range from 4.7 µH to 10 µH. An inductance value of
4.7 µH is recommended for output voltages below 15V.
For higher output voltages, up to 32V, an inductance
value of 10 µH is optimum. While the device operates
at low inputs, below 3.0V, a low value inductor (2.2 µH
or 3.3 µH) ensures better stability but limited output
power capability. Usually, this is a good trade-off as
boost converters powered from two-cell batteries are
low-power applications.
The MCP1661 device is internally compensated so
output capacitance range is limited. See Table 5-1 for
the recommended output capacitor range.
An output capacitance higher than 10 µF adds a
better load step response and high-frequency noise
attenuation, especially while stepping from light to
heavy current loads. In addition, 2 x 10 µF output
capacitors ensure a better recovery of the output after
a short period of overloading.
While the N-Channel switch is on, the output current
is supplied by the output capacitor COUT. The amount
of output capacitance and equivalent series
resistance will have a significant effect on the output
ripple voltage. While COUT provides load current, a
voltage drop also appears across its internal ESR that
results in ripple voltage.
Peak-to-peak output ripple voltage also depends on
the equivalent series inductance (ESL) of the output
capacitor. There are ceramic capacitors with special
DS20005315B-page 16
 2014-2015 Microchip Technology Inc.
MCP1661
TABLE 5-2:
MCP1661 RECOMMENDED
INDUCTORS FOR BOOST
CONVERTERS
Part Number
Value
(µH)
DCR

(typ.)
ISAT
(A)
Size
WxLxH (mm)
Coilcraft
MSS5131-472
4.7
0.038
1.42
5.1x5.1x3.1
XFL4020-472
4.7
0.057
2.7
4.2x4.2x2.1
LPS5015-562
5.6
0.175
1.6
5.0x5.0x1.5
LPS6235-103
10
0.065
1.5
6.2x6.2x3.5
XAL4040-103
10
0.092
1.9
4.3x4.3x4.1
Würth Elektronik
744025004 WE-TPC
4.7
0.1
1.7
2.8x2.8x2.8
744043004 WE-TPC
4.7
0.05
1.7
4.8x4.8x2.8
744773112 WE-PD2
10
0.156
1.6
4.0x4.5x3.2
74408943100 WE-SPC
10
0.082
2.1
4.8x4.8x3.8
TDK Corporation
B82462G4472
4.7
0.04
1.8
6.3x6.3x3.0
B82462G4103
10
0.062
1.3
6.3x6.3x3.0
VLCF4024T-4R7
4.7
0.087
1.43
4.0x4.0x2.4
Several parameters are used to select the correct
inductor: maximum rated current, saturation current
and copper resistance (DCR). For boost converters,
the inductor current is much higher than the output
current. The average inductor current is equal to the
input current. The inductor’s peak current is 30-40%
higher than the average. The lower the inductor DCR,
the higher the efficiency of the converter: a common
trade-off in size versus efficiency.
The saturation current typically specifies a point at
which the inductance has rolled off a percentage of the
rated value. This can range from a 20% to 40%
reduction in inductance. As inductance rolls off, the
inductor ripple current increases, as does the peak
switch current. It is important to keep the inductance
from rolling off too much, causing switch current to
reach the peak limit.
5.6
Rectifier Diode Selection
Schottky diodes are used to reduce losses. The diode’s
current rating has to be equal or higher than the
maximum output current. The diode’s reverse
breakdown voltage must be higher than the internal
switch rating voltage of 36V.
The converter’s efficiency will be improved if the
voltage drop across the diode is lower. The forward
voltage rating is forward-current dependent, which is
equal in particular to the load current.
For high currents and high ambient temperatures, use
a diode with good thermal characteristics.
 2014-2015 Microchip Technology Inc.
TABLE 5-3:
Type
PMEG2005
RECOMMENDED SCHOTTKY
DIODES
VOUTmax
TA
18V
< 85°C
PMEG4005
36V
< 85°C
MBR0520
18V
< 125°C
MBR0540
36V
< 125°C
5.7
SEPIC Converter Considerations
One of the advantages of using MCP1661 in SEPIC
topology is the usage of an output disconnect feature.
Also, the output voltage may be lower or higher than
the input voltage, resulting in buck or boost operation.
Input voltage is limited to the 2.4-5.5V range.
One major advantage is that the SEPIC converter allows
3.0V or 3.3V buck-boost application from a Li-Ion battery
with load disconnect. Also, SEPIC is recommended for
higher output voltages where an input-to-output isolation
is necessary (due to the coupling capacitor). An
application example is shown in Figure 6-3.
The maximum output voltage, VOUTmax, must be
limited to the sum of (VIN + VOUT) < 36V, which is the
maximum internal switch DC rating. VIN must be ≤ 5.5V.
Some extra aspects need to be taken into account
when choosing the external components:
• the DC voltage rating of the coupling capacitor
should be at least equal to the maximum input
voltage
• the average current rating of the rectifier diode’s is
equal to the output load current
• the peak current of the rectifier diode is the same
as the internal switch current, ISW = IIN + IOUT.
See the notes on Figure 6-3 in Section 6.0 “Typical
Application Circuits” for some recommended 1:1
coupled inductors.
5.8
Thermal Calculations
The MCP1661 device is available in two different
packages (5-lead SOT-23 and 8-lead 2x3 TDFN). By
calculating the power dissipation and applying the
package thermal resistance (JA), the junction
temperature is estimated. The maximum continuous
junction temperature rating for the MCP1661 device is
+125°C.
To quickly estimate the internal power dissipation for
the switching boost regulator, an empirical calculation
using measured efficiency can be used. Given the
measured efficiency, the internal power dissipation is
estimated by Equation 5-2.
DS20005315B-page 17
MCP1661
5.9
EQUATION 5-2:
PCB Layout Information
Good printed circuit board layout techniques are
important to any switching circuitry, and switching
power supplies are no different. When wiring the
switching high-current paths, short and wide traces
should be used. Therefore, it is important that the input
and output capacitors be placed as close as possible to
the MCP1661 to minimize the loop area.
VOUT  I OUT
 ------------------------------------ – V
OUT  I OUT  = P Dis
 Efficiency 
The difference between the first term, input power, and
the second term, power delivered, is the power
dissipated when using the MCP1661 device. This is an
estimate, assuming that most of the power lost is
internal to the MCP1661 and not CIN, COUT, the diode
and the inductor. There is some percentage of power
lost in the boost inductor and rectifier diode, with very
little loss in the input and output capacitors. For a more
accurate estimation of the internal power dissipation,
subtract the IINRMS2 x LDCR and IOUT x VF power
dissipation (where INRMS is the average input current,
LDCR is the inductor series resistance and VF is the
diode voltage drop).
The feedback resistors and feedback signal should be
routed away from the switching node and the switching
current loop. When possible, ground planes and traces
should be used to help shield the feedback signal and
minimize noise and magnetic interference.
EN
+VIN
CIN
L
MCP1661
GND
GND
RBOT
1
A
RTOP
Vias to GND Bottom Plane
D
GND
K
COUT
+VOUT
Vias to GND Bottom Plane
GND Bottom Plane
FIGURE 5-1:
DS20005315B-page 18
5-Lead SOT-23 Recommended Layout.
 2014-2015 Microchip Technology Inc.
MCP1661
A
L
K
+VOUT
D
+VIN
COUT
CIN
EN Routed on Bottom Side
GND
MCP1661
Via to GND
1
EN
RBOT
RTOP
GND
GND Bottom Plane
FIGURE 5-2:
Vias to GND
Bottom Plane
Routed to Bottom Side
8-Lead TDFN Recommended Layout.
 2014-2015 Microchip Technology Inc.
DS20005315B-page 19
MCP1661
6.0
TYPICAL APPLICATION CIRCUITS
L
4.7 µH
CIN
10 µF
VIN
2.4V-3.0V
MCP1661
VFB
+
ALKALINE
VOUT
12V, 75 mA
SW
VIN
EN
-
D
Schottky
RTOP
1.05 M
COUT
10 µF
RBOT
120 k
GND
ON
OFF
ALKALINE
+
-
Component
Value
Manufacturer
CIN
10 µF
TDK Corporation
C2012X7R1A106K125AC Cap. ceramic 10 µF 10V 10% X7R 0805
COUT
10 µF
TDK Corporation
C3216X7R1C106K160AC Cap. ceramic 10 µF 16V 10% X7R 1206
4.7 µH
Coilcraft
XFL4020-472MEB
L
Part Number
RTOP
1.05 MΩ Yageo Corporation
RC0805FR-071M05L
RBOT
120 kΩ Yageo Corporation
RC0805FR-07120KL
D
—
FIGURE 6-1:
DS20005315B-page 20
NXP Semiconductor PMEG2005EH,115
Comment
Inductor Power 4.7 µH 2A SMD
Res. 1.05 MΩ 1/8W 1% 0805 SMD
Res. 120 kΩ 1/8W 1% 0805 SMD
Diode Schottky 20V 0.5A SOD123F
Two Alkaline Cells to 12V Boost Converter.
 2014-2015 Microchip Technology Inc.
MCP1661
D
Schottky
L
10 µH
CIN
10 µF
VIN
3.0V-4.2V
SW
RTOP
1.05 M
VIN
+
LI-ION
MCP1661
VFB
EN
-
VOUT
24V, 50 mA
COUT
10 µF
RBOT
56 k
GND
Component
Value
Manufacturer
CIN
10 µF
TDK Corporation
C2012X7R1A106K125AC Cap. ceramic 10 µF 10V 10% X7R 0805
COUT
10 µF
TDK Corporation
C3216X7R1V106K160AC Cap. ceramic 10 µF 35V 10% X7R 1206
L
10 µH
EPCOS AG
B82462G4103M000
RTOP
1.05 M Yageo Corporation RC0805FR-071M05L
RBOT
56 k
D
—
FIGURE 6-2:
Part Number
Comment
Inductor Power 10 µH 1.5A SMD
Res. 1.05 M 1/8W 1% 0805 SMD
Yageo Corporation RC0805FR-0756KL
Res. 56 k 1/8W 1% 0805 SMD
Micro Commercial
Components
Diode Schottky 40V 0.5A SOD123
MBR0540-TP
Single Li-Ion Cell to 24V Output Boost Converter.
 2014-2015 Microchip Technology Inc.
DS20005315B-page 21
MCP1661
CC
1 µF
L1A(1)
4.7 µH
CIN
4.7-10 µF
VIN
3.0V-4.2V
SW
VIN
MCP1661
VFB
LI-ION
+
EN
-
D
Schottky
VOUT
3.3V, 250 mA
L1B(1)
4.7 µH
RTOP
2.2 k
RBOT
1.3 k
COUT
4.7-10 µF
GND
ON
OFF
Note 1: Recommended 1:1 coupled inductors.
Component Value
Manufacturer
Part Number
Comment
CIN
10 µF TDK Corporation
COUT
10 µF TDK Corporation
C3216X7R1V106K160AC Cap. ceramic 10 µF 35V 10% X7R 1206
1 µF
C2012X7R1E105K125AB Cap. ceramic 1 µF 25V 10% X7R 0805
CC
L
TDK Corporation
C2012X7R1A106K125AC Cap. ceramic 10 µF 10V 10% X7R 0805
4.7 µH Würth Elektronik
744878004
Inductor Array 2 Coil 4.7 µH SMD
RTOP
2.2 k Yageo Corporation
RC0805FR-072K2L
Res. 2.2 k 1/8W 1% 0805 SMD
RBOT
1.3 k Yageo Corporation
RC0805FR-071K3L
Res. 1.3 k 1/8W 1% 0805 SMD
NXP Semiconductors PMEG2020AEA,115
Diode Schottky 20V 2A SOD323
D
—
FIGURE 6-3:
Single Li-Ion Cell to 3.3V Output Buck-Boost (SEPIC) Converter with 1:1 Coupled
Inductors and Load Disconnect.
DS20005315B-page 22
 2014-2015 Microchip Technology Inc.
MCP1661
TR
25 µH
CIN
10 µF
VIN
3.3V-4.2V
D
Schottky
VOUT
12V
CFF
22-33 pF
SW
VIN
+
LI-ION
MCP1661
VFB
EN
-
RTOP
1.05 M
COUT
10 µF
RBOT
120 k
GND
ON
OFF
Component
Value
Manufacturer
Part Number
Comment
CIN
10 µF
TDK Corporation
C2012X7R1A106K125AC Cap. ceramic 10 µF 10V 10% X7R 0805
COUT
10 µF
TDK Corporation
C3216X7R1V106K160AC Cap. ceramic 10 µF 35V 10% X7R 1206
CFF
27 pF
TDK Corporation
C1608NP02A270J080AA Cap. ceramic 27 pF 100V 5% NP0 0603
TR
25 µH
Würth Elektronik
750310799
Trans. Flyback LT3573 25 µH SMD
RTOP
1.05 M Yageo Corporation RC0805FR-071M05L
Res. 1.05 M 1/8W 1% 0805 SMD
RBOT
120 k Yageo Corporation RC0805FR-07120KL
Res. 120 k 1/8W 1% 0805 SMD
D
FIGURE 6-4:
Example.
—
Micro Commercial
Components
MBR0540-TP
Diode Schottky 40V 0.5A SOD123
Single Li-Ion Cell to 12V Flyback Converter for Low Load Currents Application
 2014-2015 Microchip Technology Inc.
DS20005315B-page 23
MCP1661
RBOT
D
Schottky
L
4.7 µH
CIN
10 µF
VIN
2.4V-3.0V
SW
VIN
+
ALKALINE
MCP1661
VFB
EN
-
VOUT
12V, 50 mA
C1
0.1 µF
RTOP
1.05 M
COUT
10 µF
RBOT
120 k
GND
ON
+
ALKALINE
OFF
V OUT
RBOT  ----------------  100
IOUT
-
Component
Value
Manufacturer
CIN
10 µF
TDK Corporation
COUT
10 µF
TDK Corporation
C3216X7R1V106K160AC Cap. ceramic 10 µF 35V 10% X7R 1206
C1
0.1 µF
TDK Corporation
C1608X7R1E104K080AA Cap. ceramic 0.1 µF 25V 10% X7R 0603
4.7 µH
Würth Elektronik
744043004
L
Part Number
Comment
C2012X7R1A106K125AC Cap. ceramic 10 µF 10V 10% X7R 0805
RTOP
1.05 M Yageo Corporation RC0805FR-071M05L
RBOT
120 k Yageo Corporation RC0805FR-07120KL
Inductor Power 4.7 µH 1.55A SMD
Res. 1.05 M 1/8W 1% 0805 SMD
Res. 120 k 1/8W 1% 0805 SMD
D
—
Micro Commercial MBR0540-TP
Components
Diode Schottky 40V 0.5A SOD123
Q
—
Micro Commercial MMBT3906-TP
Components
Trans. SS PNP 40V 300MW SOT-23
FIGURE 6-5:
Example.
DS20005315B-page 24
Two Alkaline Cells to 12V Boost Converter with Load Disconnect Application
 2014-2015 Microchip Technology Inc.
MCP1661
7.0
PACKAGING INFORMATION
7.1
Package Marking Information
5-Lead SOT-23
Example
AAAL5
25256
8-Lead TDFN (2x3x0.75 mm)
Example
ABZ
525
25
Legend: XX...X
Y
YY
WW
NNN
e3
*
Note:
Customer-specific information
Year code (last digit of calendar year)
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
Pb-free JEDEC® designator for Matte Tin (Sn)
This package is Pb-free. The Pb-free JEDEC designator ( e3 )
can be found on the outer packaging for this package.
In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for customer-specific information.
 2014-2015 Microchip Technology Inc.
DS20005315B-page 25
MCP1661
.# #$ # /
## +22--- 2
! -
/ 0 # 1 /
% # # ! #
b
N
E
E1
3
2
1
e
e1
D
A2
A
c
φ
A1
L
L1
3#
4#
5$8 %1
4
44""
5
5
7
(
!1#
6$# ! 4
56
()*
!1#
6, 9 #
! !1 /
/
# !%%
6, <!#
! !1 /
6, 4 #
<!#
)*
:
;
:
(
:
(
"
:
"
:
;
:
.#4 #
4
:
=
.# #
4
(
:
;
.# >
:
>
4
;
:
=
!/
4 !<!#
8
:
(
!"!#$! !% #$ !% #$ # & !
!# "'(
)*+ ) # & #, $ --#$## ! - * )
DS20005315B-page 26
 2014-2015 Microchip Technology Inc.
MCP1661
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
 2014-2015 Microchip Technology Inc.
DS20005315B-page 27
MCP1661
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
DS20005315B-page 28
 2014-2015 Microchip Technology Inc.
MCP1661
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
 2014-2015 Microchip Technology Inc.
DS20005315B-page 29
MCP1661
! " #$%&''()*+, !
.# #$ # /
## +22--- 2
DS20005315B-page 30
! -
/ 0 # 1 /
% # # ! #
 2014-2015 Microchip Technology Inc.
MCP1661
APPENDIX A:
REVISION HISTORY
Revision B (February 2015)
The following is the list of modifications:
1.
2.
3.
Updated Section 6.0 “Typical Application
Circuits”.
Added legend tables for Figures 6-3 to 6-5.
Minor typographical corrections.
Revision A (June 2014)
• Original Release of this Document.
 2014-2015 Microchip Technology Inc.
DS20005315B-page 31
MCP1661
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO.
[X](1)
X
/XX
Device
Tape and Reel
Option
Temperature
Range
Package
Examples:
a)
b)
Device:
MCP1661: High-Voltage Step-Up LED Driver with UVLO and
OLP
Tape and Reel
Option:
T
= Tape and Reel(1)
Temperature
Range:
E
= -40C to +125C (Extended)
Package:
MN*
MCP1661T-E/MNY: Tape and Reel,
Extended temperature,
8LD TFDN package
MCP1661T-E/OT:
Tape and Reel,
Extended temperature,
5LD SOT-23 package
Note 1:
OT
*Y
DS20005315B-page 32
= Plastic Dual Flat, No Lead – 2x3x0.75 mm Body
(TDFN)
= Plastic Small Outline Transistor (SOT-23)
= Nickel palladium gold manufacturing designator.
Only available on the TDFN package.
Tape and Reel identifier only appears in the
catalog part number description. This
identifier is used for ordering purposes and
is not printed on the device package. Check
with your Microchip Sales Office for package
availability with the Tape and Reel option.
 2014-2015 Microchip Technology Inc.
Note the following details of the code protection feature on Microchip devices:
•
Microchip products meet the specification contained in their particular Microchip Data Sheet.
•
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•
Microchip is willing to work with the customer who is concerned about the integrity of their code.
•
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Information contained in this publication regarding device
applications and the like is provided only for your convenience
and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
MICROCHIP MAKES NO REPRESENTATIONS OR
WARRANTIES OF ANY KIND WHETHER EXPRESS OR
IMPLIED, WRITTEN OR ORAL, STATUTORY OR
OTHERWISE, RELATED TO THE INFORMATION,
INCLUDING BUT NOT LIMITED TO ITS CONDITION,
QUALITY, PERFORMANCE, MERCHANTABILITY OR
FITNESS FOR PURPOSE. Microchip disclaims all liability
arising from this information and its use. Use of Microchip
devices in life support and/or safety applications is entirely at
the buyer’s risk, and the buyer agrees to defend, indemnify and
hold harmless Microchip from any and all damages, claims,
suits, or expenses resulting from such use. No licenses are
conveyed, implicitly or otherwise, under any Microchip
intellectual property rights.
Trademarks
The Microchip name and logo, the Microchip logo, dsPIC,
FlashFlex, flexPWR, JukeBlox, KEELOQ, KEELOQ logo, Kleer,
LANCheck, MediaLB, MOST, MOST logo, MPLAB,
OptoLyzer, PIC, PICSTART, PIC32 logo, RightTouch, SpyNIC,
SST, SST Logo, SuperFlash and UNI/O are registered
trademarks of Microchip Technology Incorporated in the
U.S.A. and other countries.
The Embedded Control Solutions Company and mTouch are
registered trademarks of Microchip Technology Incorporated
in the U.S.A.
Analog-for-the-Digital Age, BodyCom, chipKIT, chipKIT logo,
CodeGuard, dsPICDEM, dsPICDEM.net, ECAN, In-Circuit
Serial Programming, ICSP, Inter-Chip Connectivity, KleerNet,
KleerNet logo, MiWi, MPASM, MPF, MPLAB Certified logo,
MPLIB, MPLINK, MultiTRAK, NetDetach, Omniscient Code
Generation, PICDEM, PICDEM.net, PICkit, PICtail,
RightTouch logo, REAL ICE, SQI, Serial Quad I/O, Total
Endurance, TSHARC, USBCheck, VariSense, ViewSpan,
WiperLock, Wireless DNA, and ZENA are trademarks of
Microchip Technology Incorporated in the U.S.A. and other
countries.
SQTP is a service mark of Microchip Technology Incorporated
in the U.S.A.
Silicon Storage Technology is a registered trademark of
Microchip Technology Inc. in other countries.
GestIC is a registered trademarks of Microchip Technology
Germany II GmbH & Co. KG, a subsidiary of Microchip
Technology Inc., in other countries.
All other trademarks mentioned herein are property of their
respective companies.
© 2014-2015, Microchip Technology Incorporated, Printed in
the U.S.A., All Rights Reserved.
ISBN: 978-1-63277-121-6
QUALITY MANAGEMENT SYSTEM
CERTIFIED BY DNV
== ISO/TS 16949 ==
 2014-2015 Microchip Technology Inc.
Microchip received ISO/TS-16949:2009 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
DS20005315B-page 33
Worldwide Sales and Service
AMERICAS
ASIA/PACIFIC
ASIA/PACIFIC
EUROPE
Corporate Office
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7200
Fax: 480-792-7277
Technical Support:
http://www.microchip.com/
support
Web Address:
www.microchip.com
Asia Pacific Office
Suites 3707-14, 37th Floor
Tower 6, The Gateway
Harbour City, Kowloon
China - Xiamen
Tel: 86-592-2388138
Fax: 86-592-2388130
Austria - Wels
Tel: 43-7242-2244-39
Fax: 43-7242-2244-393
China - Zhuhai
Tel: 86-756-3210040
Fax: 86-756-3210049
Denmark - Copenhagen
Tel: 45-4450-2828
Fax: 45-4485-2829
India - Bangalore
Tel: 91-80-3090-4444
Fax: 91-80-3090-4123
France - Paris
Tel: 33-1-69-53-63-20
Fax: 33-1-69-30-90-79
India - New Delhi
Tel: 91-11-4160-8631
Fax: 91-11-4160-8632
Germany - Dusseldorf
Tel: 49-2129-3766400
Atlanta
Duluth, GA
Tel: 678-957-9614
Fax: 678-957-1455
Hong Kong
Tel: 852-2943-5100
Fax: 852-2401-3431
Australia - Sydney
Tel: 61-2-9868-6733
Fax: 61-2-9868-6755
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Tel: 86-10-8569-7000
Fax: 86-10-8528-2104
Austin, TX
Tel: 512-257-3370
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Tel: 86-28-8665-5511
Fax: 86-28-8665-7889
Boston
Westborough, MA
Tel: 774-760-0087
Fax: 774-760-0088
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Tel: 86-23-8980-9588
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Tel: 630-285-0071
Fax: 630-285-0075
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Tel: 216-447-0464
Fax: 216-447-0643
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Detroit
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Tel: 248-848-4000
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Tel: 281-894-5983
Indianapolis
Noblesville, IN
Tel: 317-773-8323
Fax: 317-773-5453
Los Angeles
Mission Viejo, CA
Tel: 949-462-9523
Fax: 949-462-9608
New York, NY
Tel: 631-435-6000
San Jose, CA
Tel: 408-735-9110
Canada - Toronto
Tel: 905-673-0699
Fax: 905-673-6509
China - Dongguan
Tel: 86-769-8702-9880
China - Hangzhou
Tel: 86-571-8792-8115
Fax: 86-571-8792-8116
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Tel: 49-89-627-144-0
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Tel: 81-6-6152-7160
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Germany - Pforzheim
Tel: 49-7231-424750
Italy - Milan
Tel: 39-0331-742611
Fax: 39-0331-466781
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Tel: 81-3-6880- 3770
Fax: 81-3-6880-3771
Italy - Venice
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Tel: 82-53-744-4301
Fax: 82-53-744-4302
Netherlands - Drunen
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Fax: 31-416-690340
China - Hong Kong SAR
Tel: 852-2943-5100
Fax: 852-2401-3431
Korea - Seoul
Tel: 82-2-554-7200
Fax: 82-2-558-5932 or
82-2-558-5934
China - Nanjing
Tel: 86-25-8473-2460
Fax: 86-25-8473-2470
Malaysia - Kuala Lumpur
Tel: 60-3-6201-9857
Fax: 60-3-6201-9859
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Tel: 86-532-8502-7355
Fax: 86-532-8502-7205
Malaysia - Penang
Tel: 60-4-227-8870
Fax: 60-4-227-4068
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Tel: 86-21-5407-5533
Fax: 86-21-5407-5066
Philippines - Manila
Tel: 63-2-634-9065
Fax: 63-2-634-9069
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Tel: 86-24-2334-2829
Fax: 86-24-2334-2393
Singapore
Tel: 65-6334-8870
Fax: 65-6334-8850
China - Shenzhen
Tel: 86-755-8864-2200
Fax: 86-755-8203-1760
Taiwan - Hsin Chu
Tel: 886-3-5778-366
Fax: 886-3-5770-955
China - Wuhan
Tel: 86-27-5980-5300
Fax: 86-27-5980-5118
Taiwan - Kaohsiung
Tel: 886-7-213-7828
China - Xian
Tel: 86-29-8833-7252
Fax: 86-29-8833-7256
Poland - Warsaw
Tel: 48-22-3325737
Spain - Madrid
Tel: 34-91-708-08-90
Fax: 34-91-708-08-91
Sweden - Stockholm
Tel: 46-8-5090-4654
UK - Wokingham
Tel: 44-118-921-5800
Fax: 44-118-921-5820
Taiwan - Taipei
Tel: 886-2-2508-8600
Fax: 886-2-2508-0102
Thailand - Bangkok
Tel: 66-2-694-1351
Fax: 66-2-694-1350
01/27/15
DS20005315B-page 34
 2014-2015 Microchip Technology Inc.