Linear Technology LT3066 Quick setup guide

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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 LT
®
3066. 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 25µVRMS 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.
LT3066has a PWRGD pin which goes high whentheoutput
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 TA= 25°C
PARAMETER CONDITIONS MIN TYP MAX
Input Voltage Range (V) VOUT = 3.3V 3.9 45
Output Voltage VOUT (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) VIN = 5V, VOUT = 3.3V, R10 = 604Ω 445 497 545

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DEMO MANUAL DC2437A
Quick start proceDure
Demonstration circuit 2437 is easy to set up to evaluate
the performance of the LT3066. Refer to Figure 1 for
proper measurement equipment setup and follow the
procedure below:
NOTE: Make sure that the input voltage does not exceed
45V.
NOTE: The shutdown jumper JP2 shunt is required to be
placed in the OFF or ON position for proper operation.
NOTE: Place the output voltage selection jumper JP1 at
the desired position.
NOTE: Do not hot-plug the input voltage terminal VIN. The
absolute maximum voltage on VIN is 50V and hot-plugging
a power supply through wire leads to the demonstration
circuit can cause the voltage on the extremely low ESR
ceramic input capacitor to ring to twice its DC value. In
order to protect the IC, a higher ESR Aluminum Electro-
lytic capacitor is placed at the input terminals. This may
protect against some, but not all, input transients due to
hot-plugging with a power supply. See Application Note
88 for more details.
NOTE: Connect the power supply (with power off), load,
and meters as shown in Figure 1.
1. After all connections are made, turn on the input power
and verify the output voltage according to the output
voltage selection jumper JP1. If the output voltage is
different from the above values, use the USER option
and install R8. Select R8 according to the following
equation:
R8 = (VOUT/0.6 – 1) •61.9k
NOTE: If the output voltage is too low, temporarily
disconnect the load to make sure that the load is not
set too high.
2. Once the proper output voltage is established, adjust the
load within the operating range and observe the output
voltage regulation, PWRGD and other parameters.

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DEMO MANUAL DC2437A
Quick start proceDure
Figure 1. Proper Measurement Equipment Setup
Figure 2. Measuring Input or Output Ripple
V
OUT
GND

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DEMO MANUAL DC2437A
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 C2 CAP, 10µF, X7R, 50V, 10%, 1210 MURATA, GRM32ER71H106KA12L
2 3 C3, C4, C5 CAP, 3.3µF, X7R, 25V, 10%, 0805 MURATA, GRM21BR71E335KA73L
3 2 C6, C7 CAP, 0.01µF, X7R, 16V, 10%, 0603 AVX, 0603YC103KAT2A
4 1 C8 CAP, 0.022µF, X7R, 16V, 10%, 0603 MURATA, GRM188R71C223KA01D
5 1 C9 CAP, 0.47µF, X7R, 50V, 10%, 0603 TDK, C1608X7R1H474K080AC
6 2 R1, R9 RES, 61.9kΩ, 1%, 1/10W, 0603 VISHAY, CRCW060361K9FKEA
7 1 R2 RES, 93.1kΩ, 1%, 1/10W, 0603 VISHAY, CRCW060393K1FKEA
8 1 R3 RES, 124kΩ, 1%, 1/10W, 0603 PANASONIC, ERJ3EKF1243V
9 1 R4 RES, 143kΩ, 1%, 1/10W, 0603 VISHAY, CRCW0603143KFKEA
10 1 R5 RES, 196kΩ, 1%, 1/10W, 0603 VISHAY, CRCW0603196KFKEA
11 1 R6 RES, 280kΩ, 1%, 1/10W, 0603 VISHAY, CRCW0603280KFKEA
12 1 R7 RES, 453kΩ, 1%, 1/10W, 0603 VISHAY, CRCW0603453KFKEA
13 1 R10 RES, 604Ω, 1%, 1/10W, 0603 VISHAY, CRCW0603604RFKEA
14 1 R11 RES, 499kΩ, 1%, 1/10W, 0603 PANASONIC, ERJ3EKF4993V
15 1 U1 IC, LOW NOISE LINEAR REGULATOR, 4MM × 3MM, DFN LINEAR TECHNOLOGY, LT3066EDE#PBF
Additional Demo Board Circuit Components
1 0 C1 (OPT) CAP, OPTION, ALUM ELECT, SMD
2 0 R8, R12, R13, R14
(OPT)
RES, OPTION, 0603
Hardware: For Demo Board Only
1 6 E1, E2, E3, E4, E5,
E6
TEST POINT, TURRET, 0.094", MTG HOLE MILL-MAX, 2501-2-00-80-00-00-07-0
2 1 JP1 CONN, HEADER, MALE, 2X8, 2MM, THT SAMTEC, TMM-108-02-L-D
3 1 JP2 CONN, HEADER, MALE, 1X3, 2MM, THT SAMTEC, TMM-103-02-L-S
4 2 XJP1, XJP2 CONN, SHUNT, FEMALE, 2 POS, 2MM SAMTEC, 2SN-BK-G

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DEMO MANUAL DC2437A
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
schematic Diagram

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DEMO MANUAL DC2437A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2016
LT 0116 • PRINTED IN USA
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