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Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 2
Copyright
2000
Rev. 1.0b, 2005-03-03
WWW
.Microse
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i
.CO
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LX1742
High Efficiency High Voltage Boost Controller
PRODUCTION DATA SHEET
I N T E GRA T ED
PR ODUC T S
ABSOLUTE MAXI MUM RATI NGS
Supply Voltage (VIN) ..................................................................................... -0.3V to 7.0V
Output Voltage (OUT)................................................................................................25.0V
Feedback Input Voltage (VFB) ..............................................................-0.3V to VIN + 0.3V
Shutdown Input Voltage (VSHDN) ........................................................-0.3V to VIN + 0.3V
PWM Input Amplitude .........................................................................-0.3V to VIN + 0.3V
Analog Adjust Input Voltage (VADJ).................................................................-0.3V to VIN
Source Input Current (ISRC).................................................................................500mARMS
Operating Junction Temperature................................................................................ 150°C
Storage Temperature Range.........................................................................-65°C to 150°C
Peak Package Solder Reflow Temp. (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
.
TH ERM A L DATA
DU
Plastic MSOP 8-Pin
THERMAL RESISTANCE
-JUNCTION TO AMBIENT,
θJA
206
°C/W
THERMAL RESISTANCE
-JUNCTION TO CASE,
θJC
39
°C/W
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.
PACKAGE PIN OUT
1
2
4
3
5
6
8
7
SW
FB
IN
GND
OUT
CS
ADJ
DU PACKAGE
(Top View)
SHDN
RoHS / Pb-free 100% Matte Tin Lead Finish
FUNCTIONAL PIN DESCRIPTION
NAME
DESCRIPTION
IN
Unregulated IC Supply Voltage Input – Input range from +1.6V to 6.0V. Bypass with a 1F or greater capacitor.
FB
Feedback Input – Connect to a resistive divider network between the output and GND to set the output voltage between VCC
(IN) and 25V. The feedback threshold is 1.20V.
SHDN
Active-Low Shutdown Input – A logic low shuts down the device and reduces the supply current to 0.1A. When
shutdown, the LX1742 isolates the output from the input by turning off the internal MOSFET between LX and OUT.
Connect SHDN to VCC for normal operation.
SW
Inductor Switching Connection – Internally connected to the drain of a 28V N-channel MOSFET. LX is high impedance in
shutdown.
CS
Current-Sense Amplifier Input – Connecting a resistor between CS and GND sets the peak inductor current limit.
GND
Common terminal for ground reference.
ADJ
PWM Signal Input – Connects to the internal reference, via an internal filter and gain resistor, allowing a dynamic output
voltage adjustment ±15% in corresponding to a varying duty cycle. 50% duty cycle yields a nominal output set via the FB
pin (See Note) or ADJ input voltage range from 0.9V to 1.5V DC
OUT
Output voltage is adjustable up to 25V (maximum).
PP
AA
CC
KK
AA
GG
EE
DD
AA
TT
AA