Linear Technology DC2177A-B Demo Manual

Description
Demonstration circuit 2177A-B features the
micropower, low noise and low dropout voltage linear
regulator. The input voltage ranges from 2.1V to 45V and
the maximum output current is 200mA. A resistor divider
determines the output voltage, and a jumper adjusts the
divider to set the output voltage to either 1.2V, 1.5V, 1.8V,
2V, 2.5V, 3.3V, 5V or a voltage that is user-programmed
but requires the installation of a resistor. The output uses
a 10µF ceramic capacitor and the internal reference is
bypassed with a 10nF capacitor to reduce output noise
and program the soft-start. There is also a 10nF feedfor-
ward capacitor to improve load transient response and
decrease noise at higher output voltages. The position of
the VOUTEN jumper either pulls up the SHDN pin to the
input supply through a 100k resistor, shorts SHDN to
ground or floats the SHDN pin so it can be driven directly
by a signal applied to the SHDN terminal. The input supply
to the LT3062 is bypassed by a 2.2µF ceramic capacitor
performance summary
PARAMETER
Minimum Input Voltage, V
Maximum Input Voltage, V
Output Voltage, V
OUT
Maximum Output Current, I
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CONDITIONS
V – V
IN IN OUT
IN
V SELECT = 1.2V
OUT
V SELECT = 1.5V
OUT
V SELECT = 1.8V
OUT
V SELECT = 2V
OUT
V SELECT = 2.5V
OUT
V SELECT = 3.3V
OUT
V SELECT = 5V
OUT
V = 2.3V, V
OUT IN
DEMO MANUAL DC2177A-B
45V V
Low Noise, 200mA LDO
3062, a and there is also a 50V tantalum polymer capacitor on the
®
input to dampen ringing that may occur when the input is
hot-plugged using long leads.
The LT3062 saves energy by being micropower and low
dropout. The LT3062 has excellent regulation and fast
response to load transients and also tolerates wide input
voltage variations.
The LT3062 targets systems with inputs that are battery-
powered or have multiple sources. DC2177A-B features
the LT3062 in the 8-lead 2mm × 3mm DFN package. The
LT3062 data sheet must be read in conjunction with this
demo manual to properly use or modify demo circuit
DC2177A-B.
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
≥ 360mV
= 1.8V
OUT
LT3062
, Micropower,
IN
MIN TYP MAX
2.1
45
1.17 1.2 1.23
1.5 1.54
1.47
1.76 1.8 1.85
1.97 2.0 2.07
2.43 2.5 2.56
3.23 3.3 3.41
4.85 5.0 5.13
200
UNITS
V
V
V
V
V
V
V
V
V
mA
dc2177abf
1