Linear Technology DC1855A Demo Manual

Description
Demonstration circuit 1855A is a dual, micropower, low
noise and low dropout voltage linear regulator featuring
the LT3030. The input voltages are independent for each
channel of DC1855A and can range from 2.2V to 20V.
Each channel has a jumper that sets the output voltage to
either 1.5V, 1.8V, 2.5V, 3.3V, 5V or a voltage that is user
programmed by the installation of a resistor. For channel 1
and channel 2, the maximum output currents are 750mA
and 250mA and the ceramic output capacitors are 22µF
and 10µF respectively. The internal reference of each
channel is bypassed with a 10nF capacitor for reduced
output noise. Each channel has a jumper for shutdown
and a terminal for PWRGD that is pulled up to the input
supply. A resistor divider can be easily added that allows
precise lockout at low input voltages.
performance summary
PARAMETER
Minimum Input Voltage, V
Maximum Input Voltage, V
Output Voltage, V
OUT
Maximum Channel 1 Output Current, I
Maximum Channel 2 Output Current, I
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CONDITIONS
V = 1.8V
IN OUT
IN
VOUT SELECT = 1.5V
VOUT SELECT = 1.8V
VOUT SELECT = 2.5V
VOUT SELECT = 3.3V
VOUT SELECT = 5V
V = 3.3V, V
OUT1 IN1
V = 3.3V, V
OUT2 IN2
DEMO MANUAL DC1855A
Low Dropout, Low Noise,
Micropower Linear Regulator
The LT3030 is well suited to applications that require
sequencing between dual regulator channels, particu-
larly microprocessor systems and instrumentation that
require low noise. Systems with batteries will benefit
from the low dropout of the LT3030 and its micropower
operation. DC1855A features the LT3030 in a 28-lead
4mm × 5mm QFN package. The LT3030 data sheet must
be read in conjunction with this demo manual to properly
use or modify demo circuit DC1855A.
Design files for this circuit board are available at
http://www.linear.com/demo
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.
Specifications are at T = 25°C
A
=1.8V
OUT1
=1.8V
OUT2
Dual 750mA/250mA
MIN TYP
20
1.48
1.77
2.45
3.21
4.86
750
250
LT3030
MAX UNITS
2.2 V
V
1.53 V
1.83 V
2.56 V
3.37 V
5.12 V
mA
mA
dc1855af
1