LX1732
I N T E G R A T E D
High Current PFM Boost Converter
P R O D U C T S
P RODUCTION D ATA S HEET
KEY FEATURES
DESCRIPTION
The output voltage programming
range of 2.2V to 5V, requires only
two external resistors via the
feedback pin (see Figure 1.0).
Output load currents of up to
200mA are achievable and the
internal MOSFET is capable of
switching up to a 1A current limit.
Quiescent current during operation
is 200µA (max) and in shutdownmode drops to a mere 1µA thus
maximizing overall battery lifetime.
The LX1732 features a low
battery-detect circuitry that alerts
system power management of low
input voltages thus allowing
portable systems to enter a powersavings mode (e.g., to protect data)
88% Efficiency
200µA Quiescent Current
0.1µA Logic Shutdown
Low-Battery Detector
8-Pin MSOP Package
APPLICATIONS/BENEFITS
Pagers
Wireless Phones
Hand-Held Computers
PDAs
RF Tags
Two-cell Alkaline Battery
Applications
Single-cell Lithium Ion 5V
Boost
WWW . Microsemi .C OM
The LX1732 is a compact, high
efficiency, step-up DC-DC boost
regulator implemented in a
BiCMOS process technology. This
device features variable frequency
operation and a built in N-channel
MOSFET power switch for
optimal functioning in low voltage
portable systems.
Start-up operation is guaranteed
from 1.1V inputs (at light load)
and the input voltage can be as low
as 0.7V after start-up.
This
attribute allows the LX1732 to
operate in an extended powersavings mode, supplying (data)
critical system components, even
after battery capacity no longer
supports normal operation.
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
PRODUCT HIGHLIGHT
VBAT
L
R3
100%
D
R4
IN
SW
SHDN
VC
VOUT
R1
LX1732
FB
LBI
COUT
90%
Efficiency (%)
CIN
80%
70%
60%
LBO
R2
GND
50%
0
25
50
75
100
125
150
175
200
Output Current
LX1732
Figure 1 – LX1732 General Circuit Topology and Typical Efficiency Performance
PACKAGE ORDER INFO
Plastic MSOP
DU
8-Pin
TA (°C)
RoHS Compliant / Pb-free
Transition DC: 0432
0 to 70
LX1732CDU
Note: Available in Tape & Reel. Append the letters “TR” to the part
number. (i.e. LX1732CDU-TR)
Copyright © 2000
Rev. 1.1c, 2005-03-03
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1
LX1732
I N T E G R A T E D
High Current PFM Boost Converter
P R O D U C T S
P RODUCTION D ATA S HEET
ABSOLUTE MAXIMUM RATINGS
PACKAGE PIN OUT
SW
1
8
GND
VIN
2
7
VC
SHDN
3
6
FB
4
5
LBO
LBI
DU PACKAGE
(Top View)
RoHS / Pb-free 100% Matte Tin Lead Finish
WWW . Microsemi .C OM
Supply Voltage (VIN) ........................................................................-0.3V to 7.0V
Output Voltage (VC) .........................................................................-0.3V to 7.0V
Switch Voltage (VSW) .......................................................................-0.3V to 7.0V
Shutdown Input Voltage (V SHDN ) ......................................... -0.3V to (VC + 0.3V)
Low Battery Detect Output (V LBO ) ...................................... -0.3V to (VC + 0.3V)
Low Battery Detect Input Voltage (VLBI) .............................. -0.3V to (VC+ 0.3V)
Feedback Input Voltage (VFB) ............................................... -0.3V to (VC+ 0.3V)
Switch Current (ILX).................................................................................. 1.0ARMS
Operating Temperature Range ............................................................ 0°C to 70°C
Operating Junction Temperature.................................................................. 150°C
Storage Temperature Range...........................................................-65°C to 150°C
Peak Package Temp for Solder Reflow (40 second max. exposure) ............. 260°C (+0, -5)
Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to
Ground. Currents are positive into, negative out of specified terminal.
THERMAL DATA
DU
Plastic MSOP 8-Pin
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA
206°C/W
39°C/W
THERMAL RESISTANCE-JUNCTION TO CASE, θJC
Junction Temperature Calculation: TJ = TA + (PD x θJC).
The θJA numbers are guidelines for the thermal performance of the device/pc-board
system. All of the above assume no ambient airflow.
FUNCTIONAL PIN DESCRIPTION
NAME
DESCRIPTION
IN
Unregulated IC Supply Voltage Input – Input range from +1.1V to 5.5V. Bypass with a 4.7µF or greater capacitor.
FB
Control pin for output voltage programming. Connect this pin to a resistive divider network between the output
and GND to obtain an output voltage between 2.0V and 5.5V.
SHDN
Active-Low Shutdown Input – A logic low shuts down the device and reduces the supply current to 0.1µA.
Connect SHDN to VCC for normal operation.
Inductor Switching Connection – Internally connected to the drain of an N-channel MOSFET.
VC
Output voltage control pin: Connect this pin to the circuit load and cathode of the switching diode.
GND
Common terminal for ground reference.
LBI
Low Battery Detect Comparator Input – Connect to a resistive divider network between the VCC and GND to set
the Low Battery Detect trip point. The LBI threshold is 0.6V.
LBO
Low Battery Detect Comparator Output – Open drain comparator output. This output is pulled low when VLBI is
less than 0.6V. LBO is high impedance during shutdown.
Copyright © 2000
Rev. 1.1c, 2005-03-03
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 2
PACKAGE DATA
SW
LX1732
I N T E G R A T E D
High Current PFM Boost Converter
P R O D U C T S
P RODUCTION D ATA S HEET
Parameter
`
PFM Regulator
Operating Voltage
Minimum Operating Voltage
Minimum Start-up Voltage
Start-up Voltage Temperature
Coefficient
Output Voltage Range
Steady State Output Current
`
`
`
Symbol
VIN
VIN
Test Conditions
Min
1.1
IOUT ≅ 1mA
TA = +25°C; IOUT < 10mA
Max
5.5
0.7
1.1
κSU
VOUT = 3.3V: GBNT
VOUT = 5V: GBNT
ILX = 100mA
2.2
250
100
Units
V
V
V
mV/°C
-2
VOUT
IOUT
LX1732
Typ
5.5
V
mA
Ω
A
µA
kHz
%
µA
1.230
300
V
nA
100
nA
RDS(ON)
ISW
ILEAK
fOSC
D
IQ
SHDN High Input Voltage
VSHDN
SHDN Low Input Voltage
Shutdown Operating Current
Low Battery Detect
Low Battery Detect Output
Voltage
Low Battery Detect Output
Leakage Current
Low Battery Threshold
Hysteresis
VSHDN
IQ
SHDN = GND
0.4
1
V
µA
V LBO
VLBI = 0V, I LBO = -1mA
0.5
V
I LBO
VLBI = VIN, V LBO = 5V
1
µA
VLBT
VHLBT
0.71
V
TA = +25°C
VFB
IFB
ISHDN
0.2
1.0
1.0
1.0
135
85
200
Internal N-FET On-resistance
Switch Current Limit
Switch Pin Leakage Current
Oscillator Frequency
Duty Cycle
Operating Current
Error Amplifier
Voltage Feed Back Threshold
Voltage Feed Back Input Current
Shutdown Circuit
SHDN Input Bias Current
0.47
VLX = 5.5V, VOUT = 5V
VFB = 1V; TA = +25°C
VFB = 1V; TA = +25°C
(into VC pin)
TA = +25°C
VFB = 1.4V
WWW . Microsemi .C OM
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, the following specifications apply over the operating ambient temperature 0°C ≤ TA ≤ 70°C
except where otherwise noted and the following test conditions: VIN = 2V, VOUT = 3.3V, RLOAD = 3kΩ, V SHDN = 2V
65
65
100
75
1.170
1.200
SHDN = GND
VIN/2
V
0.54
80
ELECTRICALS
Copyright © 2000
Rev. 1.1c, 2005-03-03
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 3
LX1732
I N T E G R A T E D
High Current PFM Boost Converter
P R O D U C T S
P RODUCTION D ATA S HEET
WWW . Microsemi .C OM
APPLICATION CIRCUITS
SW
VCO
IN
VIN
Gate Driver
Logic
Control
SHDN
Current
Sense
Shutdown
27µH
20µF
10V
GND
316KΩ
UPS5817
100KΩ
FB
IN
SW
SHDN
VC
VOUT
316KΩ
LX1732
+
VC
FB
LBI
LBO
100KΩ
-
GND
Ref = VBG/2
20µF
10V
Band Gap
VREF = 1.200V
+
LBO
-
LBI
Figure 3 – VOUT = 5.0V; IOUT = 150mA and VLBI = 2.5V
Figure 2 – LX1732 Block Diagram
VIN
VIN
27µH
20µF
10V
UPS5817
27µH
15Ω
100KΩ
20µF
UPS5817
100KΩ
IN
SW
SHDN
VC
174KΩ
LX1732
LBI
VOUT
FB
20µF
10V
IN
SW
SHDN
VC
20µF
15Ω
LX1732
237KΩ
FB
LBI
15Ω
LBO
LBO
GND
100KΩ
GND
Figure 4 – VOUT = 3.2V; IOUT = 250mA and VLBI = 1.2V
APPLICATIONS
100KΩ
Copyright © 2000
Rev. 1.1c, 2005-03-03
15Ω
15Ω
Figure 5 – LX1732 driving 5 white LEDs in parallel
where VOUT > 3.6V; IOUT = 100mA.
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 4
LX1732
I N T E G R A T E D
P R O D U C T S
High Current PFM Boost Converter
P RODUCTION D ATA S HEET
APPLICATION NOTE
OUTPUT VOLTAGE PROGRAMMING
Resistors R1 and R2 of Figure 1 program the output
voltage. An optional 1000pF capacitor is recommended
across R1 to improve the transient response and reduce
output voltage ripple (see Figure 7). The value of R2 should
be less than 250KΩ. The value of R1 can be determined
using the following equation where VREF is found in the
ELECTRICAL CHARACTERISTICS TABLE:
⎡⎛ V
⎞ ⎤
R1 = R2⎢⎜⎜ OUT ⎟⎟ − 1⎥
⎢⎣⎝ VREF ⎠ ⎥⎦
DESIGN EXAMPLE:
Let R2 equal 100K and the required VOUT equal to
5.0V.
= 316.6KΩ
DIODE SELECTION
A Schottky diode is recommended for use with the
LX1732 because it provides fast switching and superior
reverse recovery performance. The Microsemi UPS5817
(20V @ 1A) makes an effective choice for most
applications.
Copyright © 2000
Rev. 1.1c, 2005-03-03
⎡⎛ V
R3 = R4 ⎢⎜⎜ LOW BATT
⎣⎢⎝ VREF
⎞ ⎤
⎟ − 1⎥
⎟
⎠ ⎦⎥
The LBO pin’s open drain output requires a pull up resistor
(i.e., 100K typ.) to drive external CMOS logic circuits.
Connect the LBI pin to ground and omit resistors R3 and R4
when the Low Battery Detect function is not implemented.
DESIGN EXAMPLE:
Let R3 equal 100K and the required LB threshold equal
to 2.5V.
⎡⎛ 2.5V ⎞
⎤
⎟⎟ − 1⎥ = 316KΩ
0.6V
⎠
⎣⎢⎝
⎦⎥
R3 = R100⎢⎜⎜
CAPACITOR SELECTION
To minimize ripple voltage, output capacitors in the range
of 10uF to 100uF with a low series resistance (ESR) are
recommended. Multi-layer ceramic capacitors with X5R or
X7R dielectric make an effective choice because they feature
small size, very low ESR, a temperature stable dielectric, and
can be connected in parallel to increase capacitance. Other
low ESR capacitors such as solid tantalum, specialty
polymer, or organic semiconductor, make effective choices
provided that the capacitor is properly rated for the output
voltage and ripple current. Finally, choose an input capacitor
of sufficient size to effectively decouple the input voltage
source impedance (e.g., CIN > 47µF).
LAYOUT CONSIDERATIONS
The high peak currents and switching frequencies present
in DC/DC converter applications require careful attention to
device layout for optimal performance. Basic design rules
include: (1) maintaining wide traces for power components
(e.g., width > 50mils); (2) place CIN, COUT, the Schottky
diode, and the inductor close to the LX1732; (3) minimizing
trace capacitance by reducing the etch area connecting the
SW pin to the inductor; and (4) minimizing the etch length to
the LBI and FB pins to reduce noise coupling into these high
impedance sense inputs. Other considerations include
placing a 0.1uF capacitor between the LX1732 VOUT pin
and GND pin to reduce high frequency noise and decoupling
the VIN pin using a 0.1uF capacitor.
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 5
APPLICATIONS
⎡⎛ 5V ⎞
⎤
⎟⎟ − 1⎥
⎢⎣⎝ 1.20 ⎠
⎥⎦
R1 = 100K ⎢⎜⎜
LOW BATTERY DETECTION PROGRAMMING
Program the Low Battery Detect voltage threshold by
selecting values for resistors R3 and R4 (see Figure 1) using
the formula below. Use a value of less than 250KΩ for R4 to
minimize threshold error due to the internal comparator’s
offset current. The value of R3 can be determined using the
following equation.
WWW . Microsemi .C OM
FUNCTIONAL DESCRIPTION
The LX1732 implements a constant on-time and offtime PFM architecture that can deliver a 5.0V output and
over 150mA of continuous output current. The freerunning oscillator and logic-circuit initiate the internal
MOSFET switching cycle during power-up via the VC pin
(see block diagram in Figure 2)). The current passing
through the LX pin is detected by the I-sense circuit and
compared with the feedback voltage status via the logic
circuit. The internal limit for the peak current is set at
1000mA (max). The MOSFET switch remains on for the
on-time duration or until the I-sense detects the maximum
peak current, or when the feedback threshold voltage is
detected at the FB pin. The feedback threshold voltage is
set by an external resistor divider network and compared
with the internal reference voltage.
The LX1732
implements a non-load isolated shutdown mode using an
input-voltage referenced signal level via the SHDN pin.
Connect this pin to the input supply rail if the shutdown
feature is not required. The LX1732 features a low-battery
detection circuit that allows for sensing of the input voltage
supply. If the supply voltage at LBI drops below the
internal reference voltage, the internal MOSFET (opendrain) sinks current to GND.
LX1732
I N T E G R A T E D
P R O D U C T S
High Current PFM Boost Converter
P RODUCTION D ATA S HEET
APPLICATION INFORMATION
L≈
⎛
V IN
V IN
× ⎜⎜1 −
∆I L × f SW ⎝ VOUT + V FWD
⎞
⎟⎟
⎠
Step 3: Determine output capacitance. The value of the
output capacitor effects output voltage ripple and transient
performance. The ripple voltage on the output (ignoring
ESR) is the summation of the comparator overdrive voltage,
the voltage undershoot (which usually occurs during the first
switch “on” time) and overshoot that occurs at the end of the
burst when the stored energy in the inductor is delivered to
the output capacitor. An approximation of the output ripple
voltage is given by this relationship:
•
THERMAL CONSIDERATIONS
Calculating maximum power dissipation for a given
operating condition is achieved using the following
relationship:
PD(max) = [TJ(max) – TA(max)]/ΘJA
The maximum device junction temperature is specified
at 150oC and the 8 pin MSOP package thermal resistance is
206oC/W.
The LX1732 operates within specified
parameters up to a maximum ambient temperature of 70oC.
The maximum power dissipation achievable under these
constraints is (150oC - 70oC)/ 206oC/W = 0.38W and
increases to 0.58W at a device ambient temperature of 30oC.
Designers should pay close attention to PCB design, device
thermal coupling, proximity to other active components, and
access to airflow in applications that require the device to
operate close to the maximum junction temperature.
∆VOUTpp = {(IOUT*tON) / COUT } + { 0.5*(L /
COUT)*(IPEAK - IOUT)² / (VOUT – VIN) } + IPEAK*
ESRC + 10mV.
Based upon this equation, making the output capacitor large,
the inductor value small, and the peak current small will
help reduce ripple. Figure 14 shows IPEAK equal to 400mA
for a 150mA load condition.. Two 100µF tantalum
capacitors were placed in-parallel at the output. The total
ESRC is approximately 0.10Ω. The estimated ripple voltage
based upon these values is calculated to be 59mV. The
actual ripple measured in Figure 14 is less than 40mV.
Variation in tON, actual ESRC and COUT contribute to the
error associated between the measured and calculated value.
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
APPLICATIONS
CIRCUIT DESIGN EXAMPLE
Example 1
VIN = 3.0; VOUT = 5.0V+5%; IOUT = 150mA (max);
Efficiency > 80%; VOUT(ripple) < 100mV.
Step 1: Program the output voltage. This value was
already determined in the example on page 5 as 316kΩ.
Step 2: Determine an appropriate inductor value.
Determine the inductor that will result in a ripple current of
200mA. Assuming a diode forward voltage drop of 350mV
and a nominal switching frequency of 130KHz, based on the
equation above : L = 51uF; use 47uF standard value.
Copyright © 2000
Rev. 1.1c, 2005-03-03
WWW . Microsemi .C OM
INDUCTOR SELECTION
A smaller value inductor tends to have a smaller package
size. Also using a smaller value inductor can reduce output
voltage ripple. The inductor value must be large enough to
maintain a reasonable level of inductor current ripple (during a
burst period) since this will increase the DC output power
capability of the converter. The ripple current can be
estimated as:
Page 6
LX1732
I N T E G R A T E D
P R O D U C T S
High Current PFM Boost Converter
P RODUCTION D ATA S HEET
OVERVIEW
The LXE1732 evaluation board is available from
Microsemi for assessing overall circuit performance. The
evaluation board, shown in Figure 6, is 3 by 3 inches (i.e.,
7.6 X 7.6cm) square and factory calibrated for optimal
performance over a wide load range. Circuit designers can
easily modify output voltage to suit their particular
application. Moreover, inductor, capacitors, and diode are
easily swapped out to promote design verification of a
circuit that maximizes efficiency and minimizes cost for a
wide variety of applications.
The input and output
connections are described in Table 1.
Hence, VOUT during shutdown will be approximately the
input voltage minus the inductor and diode forward voltage
drop.
The LXE1732 evaluation board provides an easy and
cost effective solution for evaluation of the LX1732. The
factory installed component list for the evaluation board is
provided in Table 2 and the schematic is shown in Figure 7.
ELECTRICAL CONNECTIONS
Apply the DC input voltage directly to the VIN pin and
connect the test load to the VOUT pin. The output voltage
is factory programmed at 3.0V, however, the user may
adjust this value by changing the R1 and R2 values
accordingly. Install a wire loop at JU1 to close the circuit
connection and to examine the inductor current using a
suitable current probe.
The LX1732 exhibits a low quiescent current (IQ <
1µA: typ) during shutdown mode. This pin is pulled-up to
VIN via a 10K resistor. Grounding the SHDN test point
shuts down the IC however, the load is still capable of
drawing current through the inductor & diode circuit path.
WWW . Microsemi .C OM
EVALUATION BOARD
Figure 6 – LX1732 Evaluation Board
Table 1: Input and Output Pin Assignments
Allowable
Range
0 to 6V
LBI
V < VIN
LBO
/SHDN
VOUT
GND
N/A
0 to VIN
V > VIN
0V
Copyright © 2000
Rev. 1.1c, 2005-03-03
Description
Input power supply connection.
Low Battery Input voltage threshold sense pin: Programmed for 0.93V
nominal.
Low Battery Output voltage: Connect a DVM to LBO to observe voltage.
Ground to inhibit the LX1732
Programmed for 3.0V nominal output, adjustable via R1 and R2.
Circuit Ground
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
EVALUATION
Pin
Name
VIN
Page 7
LX1732
I N T E G R A T E D
High Current PFM Boost Converter
P R O D U C T S
P RODUCTION D ATA S HEET
EVALUATION BOARD (CONTINUED)
WWW . Microsemi .C OM
Table 2: Factory Installed Component
Description / Part No. / Supplier
Ref
CR1
Schottky Diode; 1N5817; (Microsemi)
C1
0.01µF 50VCeramic Capacitor; (various)
C2
0.1µF 50VCeramic Capacitor; (various)
C3
100µF, 6.3V Tantalum Capacitor; (various)
C4
100µF, 6.3V Tantalum Capacitor; (various)
C5
100µF, 6.3V Tantalum Capacitor; (various)
C6
100µF, 6.3V Tantalum Capacitor; (various)
L1
47µH Inductor – shielded; (various)
R1
392KΩ Resistor; (various)
R2
255KΩ Resistor; (various)
R3
150KΩ Resistor; (various)
R4
270KΩ Resistor; (various)
R5
50Ω Resistor; (various)
R6
100KΩ Resistor; (various)
U1
Boost Controller IC; LX1732CDU; (Microsemi)
Note: The minimum part set for a working power supply consists of: U1, L1, CR1, C3, C5, R1, R2
EVALUATION BOARD (CONTINUED)
CR1
UPS5817
VIN
1
R6
100K
JU1
Jumper
L1
R3
47.0µH
150K
C4&7
200µF
R1
392K
U1
VIN
SW
SHDN
VC
LBI
2
C2
0.1µF
50V
GND
LBI
R4
270K
VOUT
2
C1
0.1µF
C3
100µF
FB
LBO
LX1732CDU
EVALUATION
R2
255K
LBO
C6
100µF
R5
50
GND
GND
Figure 7 – LXE1732: LX1732 Evaluation Board Schematic
Copyright © 2000
Rev. 1.1c, 2005-03-03
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 8
LX1732
I N T E G R A T E D
High Current PFM Boost Converter
P R O D U C T S
P RODUCTION D ATA S HEET
CHARACTERISTIC CURVES
WWW . Microsemi .C OM
100%
5.200
5.000
4.800
4.600
90%
80%
Voltage (V)
Efficiency (%)
4.400
4.200
70%
4.000
3.800
3.600
3.400
3.200
3.000
2.800
60%
2.600
2.400
2.200
2.000
50%
0
25
50
75
100
125
150
175
0
200
Figure 8 – Efficiency vs. Output Current (mA)
Top: VIN = 3.0V, VOUT = 5.0V, L1 = 47.0µH; Bottom: VIN =
1.5V, VOUT = 3.0, L1 = 47.0µH.
50
75
100
125
150
175
200
Figure 9 – Line Regulation vs. Output Current (mA)
Configuration: Top: VIN = 3.0V, VOUT = 5.0V, Bottom: VIN =
1.5V, VOUT = 3.0V
Figure 11 – Switching Waveforms: CH2 = VOUT, CH1 = SW
pin, CH4 = Inductor Current where IOUT = 75mA; VIN = 1.5V;
VOUT = 3.0V; L = 47µH; COUT = 200µF
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 9
GRAPHS
Figure 10: Step Load Response
Configuration: VIN = 1.5V; CH2: VOUT = 3.0V; CH3 ILOAD =
5mA to 110mA; CH4: IL
Copyright © 2000
Rev. 1.1c, 2005-03-03
25
Output Current
Output Current
LX1732
I N T E G R A T E D
P R O D U C T S
High Current PFM Boost Converter
P RODUCTION D ATA S HEET
CHARACTERISTIC CURVES
WWW . Microsemi .C OM
Figure 12– Switching Waveforms: CH2 = VOUT, CH1 = SW
pin, CH4 = Inductor Current where IOUT = 240mA; VIN = 2.0V;
VOUT = 3.0V; L = 47µH; COUT = 200µF
Figure 13 – Switching Waveforms: CH2 = VOUT, CH1 = SW
pin, CH4 = Inductor Current where IOUT = 80mA; VIN = 3.0V;
VOUT = 5.0V; L = 47µH; COUT = 200µF
Figure 14– Switching Waveforms: CH2 = VOUT, CH1 = SW
pin, CH4 = Inductor Current where IOUT = 150mA; VIN =
3.0V; VOUT = 5.0V; L = 47µH; COUT = 200µF
GRAPHS
Copyright © 2000
Rev. 1.1c, 2005-03-03
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 10
LX1732
I N T E G R A T E D
High Current PFM Boost Converter
P R O D U C T S
P RODUCTION D ATA S HEET
PACKAGE DIMENSIONS
WWW . Microsemi .C OM
DU
8-Pin Miniature Shrink Outline Package (MSOP)
A
B
H
G
P
M
C
N
D
Dim
Note:
MILLIMETERS
MIN
MAX
2.85
3.05
2.90
3.10
–
1.10
0.25
0.40
0.65 BSC
0.38
0.64
0.13
0.18
0.95 BSC
0.40
0.70
3°
0.05
0.15
4.75
5.05
INCHES
MIN
MAX
.112
.120
.114
.122
–
0.043
0.009
0.160
0.025 BSC
0.015
0.025
0.005
0.007
0.037 BSC
0.016
0.027
3°
0.002
0.006
0.187
0.198
Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(0.006”) on any side. Lead dimension shall
not include solder coverage.
Copyright © 2000
Rev. 1.1c, 2005-03-03
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 11
MECHANICALS
A
B
C
D
G
H
J
K
L
M
N
P
K
L
LX1732
I N T E G R A T E D
High Current PFM Boost Converter
P R O D U C T S
P RODUCTION D ATA S HEET
WWW . Microsemi .C OM
NOTES
NOTES
PRODUCTION DATA – Information contained in this document is proprietary to
Microsemi and is current as of publication date. This document may not be modified in
any way without the express written consent of Microsemi. Product processing does not
necessarily include testing of all parameters. Microsemi reserves the right to change the
configuration and performance of the product and to discontinue product at any time.
Copyright © 2000
Rev. 1.1c, 2005-03-03
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 12