1
dc2437af
DEMO MANUAL DC2437A
Description
LT3066
45V, 500mA Low Noise
Linear Regulator with Programmable
Current Limit and Active Output Discharge
Demonstration circuit 2437A is an adjustable 500mA
linear regulator featuring the
. The LT3066 is a
micropower, low noise and low dropout voltage linear
regulator that operates over a 1.8V to 45V input voltage
range. The device supplies 500mA of output current with
a typical dropout voltage of 300mV. A 10nF bypass ca-
pacitor reduces output noise to 25µV
RMS
across a 10Hz
to 100kHz bandwidth and soft-starts the reference. The
LT3066’s ±45V input voltage rating combined with its
precision current limit make the IC an ideal choice for
robust, high reliability applications. LT3066 features an
NMOS pull-down that discharges the output if
SHDN
or
IN is driven low.
The LT3066’s current limit can be programmed by a single
resistor, accurate to ±10% over a wide input voltage and
temperature range. The internal current limit should be
considered when the input-to-output differential is high.
LT3066 has a PWRGD pin which goes high when the output
rises above 90% of its nominal value. If the output falls
L
, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
performance summary
below 88.4% of its nominal value for more than 25µs, the
PWRGD pin asserts low. The use of a feedforward cap may
cause the PWRGD flag to assert early during a start-up
transient. To avoid this, ensure that the REF/BYP capaci-
tor is significantly larger than the feedforward capacitor.
The LT3066 optimizes stability and transient response
with low ESR ceramic capacitors, requiring a minimum
capacitance of 3.3µF.
The LT3066 is available in thermally-enhanced 12-Lead
4mm × 3mm DFN and MSOP packages.
The LT3066 data sheet gives a complete description of
the device, operation and application information. The
data sheet must be read in conjunction with this quick
start guide for demo circuit 2437A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2437A
Specifications are at T
A
= 25°C
PARAMETER
CONDITIONS
MIN
TYP
MAX
Input Voltage Range (V)
V
OUT
= 3.3V
3.9
45
Output Voltage V
OUT
(V)
Header in JP1
Header in JP2
Header in JP3
Header in JP4
Header in JP5
Header in JP6
Header in JP7
1.176
1.46
1.75
1.94
2.43
3.23
4.85
1.2
1.5
1.8
1.99
2.5
3.32
4.99
1.22
1.54
1.74
2.04
2.57
3.41
5.13
Maximum Output Current (mA)
V
IN
= 5V, V
OUT
= 3.3V, R10 = 604Ω
445
497
545
