LT3086_15 Datasheet, PDF (1/34 Pages) Linear Technology – 40V, 2.1A Low Dropout Adjustable Linear Regulator with Monitoring and Cable Drop Compensation

LT3086
Features
40V, 2.1A Low Dropout
Adjustable Linear Regulator with Monitoring
and Cable Drop Compensation
Description
n _{Wide Input Voltage Range: 1.4V to 40V}
n _{1 Resistor Sets Output Voltage: 0.4V to 32V}
n _{Output Current: 2.1A}
n _{±2% Tolerance Over Line, Load and Temperature}
n _{Output Current Monitor: IMON = IOUT/1000}
n _{Temperature Monitor with Programmable}
Thermal Limit
n _{Programmable Cable Drop Compensation}
n _{Parallel Multiple Devices for Higher Current}
n _{Dropout Voltage: 330mV}
n _{1 Capacitor Soft-Starts Output and Decreases Noise}
n _{Low Output Noise: 40µVRMS (10Hz to 100kHz)}
n _{Precision, Programmable External Current Limit}
n _{Power Good Flag with Programmable Threshold}
n _{Ceramic Output Capacitors: 10µF Minimum}
n _{Quiescent Current in Shutdown: <1µA}
n _{Reverse-Battery, -Current and -Output Protection}
n _{Available in 5mm × 4mm 16-Lead DFN,}
16-Lead TSSOP, 7-Lead DD-Pak and 7-Lead TO-220.
Applications
n _{Programmable Linear Regulator}
n _{Post Regulator for Switching Supplies}
n _{USB Power Supplies}
n _{High Reliability Power Supplies}
The LT^®3086 is a multi-feature, low dropout, low noise
2.1A linear regulator that operates over a 1.4V to 40V
input supply range. Dropout voltage at 2.1A is typically
330mV. One resistor sets output voltage from 0.4V to 32V.
Output voltage tolerance is guaranteed to ±2% over line,
load and temperature. The LT3086 is stable with ceramic
output capacitors, requiring a minimum of 10µF.
The LT3086’s programmable cable drop compensation
cancels output voltage errors caused by resistive connec-
tions to the load. A master/slave configuration allows paral-
leling of multiple devices for higher load current and heat
spreading without external ballast resistor requirements.
Output current and temperature monitoring along with
a power good flag provide system diagnostic and debug
capability. Internal fault circuitry includes thermal shutdown
and current limit with foldback. Thermal limit and current
limit are also externally programmable.
Packages include the thermally enhanced 16-lead
(5mm × 4mm) DFN, 16-lead TSSOP, 7-lead DD-Pak and
7-lead TO-220.
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.
Typical Application
5V, 2.1A USB Supply with Cable Drop Compensation
V_IN
6V TO
15V
10µF
V_TEMP
10mV/°C
25°C = 250mV
TO ADC
0.8V AT 2.24A
FULL-SCALE
R_MON
357Ω
1%
IN
OUT
LT3086
SHDN
SET
TEMP
TRACK
CDC
I_MON R_PWRGD
I_LIM
PWRGD
GND
R_SET
90.9k + 1.1k
1%
R_CDC
1%
V_OUT
82.5k 10µF
1%
100k
CABLE
R_LINE1
R_CDC 1%
V_PWRGD
R_LINE2
R_CDC
=
R_MON •R_SET
3000 •R_WIRE
R_WIRE = R_LINE1 +R_LINE2 *
*SEE APPLICATIONS INFORMATION
FOR INDUCTANCE EFFECTS ASSOCIATED
WITH R_WIRE
V_LOAD
5V AT 2.1A
3086 TA01
For more information www.linear.com/LT3086
Transient Response with Cable
Drop Compensation (CDC)
5.8
5.6
V_IN = 6V
R_MON = 357Ω
5.4
R_WIRE = 0.24Ω
5.2
V_OUT WITH CDC
R_CDC = 46.4k
5.0
4.8
V_LOAD WITH CDC
4.6
V_LOAD WITHOUT CDC
4.4
4.2
2
∆I_LOAD = 0.5A TO 1.5A
1
0
0 80 160 240 320 400 480 560 640 720 800
TIME (µs)
3060 TA04b
3086fa
1