LT8471_15 Datasheet, PDF (1/34 Pages) Linear Technology – Dual Multitopology DC/DC Converters with 2A Switches and Synchronization

LT8471
Dual Multitopology
DC/DC Converters with 2A
Switches and Synchronization
Features
n _{Dual 2A and One 500mA, 50V Internal Power}
Switch Channels
n _{2A Primary Channels Can Be Buck, Boost, SEPIC,}
ZETA, Flyback or Inverting DC/DC Converter
n _{500mA Skyhook Channel Efficiently Generates}
Boosted Input Voltage
n _{Wide Input Voltage Range of 2.6V to 50V}
n _{UVLO and OVLO Programmable on OV/UV Pin}
n _{Soft-Start Programmable for Each Channel}
n _{Fixed Frequency PWM (Set by RT Pin or}
Synchronized to External Clock)
n _{Anti-Phase Switching Reduces Input Ripple}
n _{20-Lead TSSOP Package}
Applications
n _{Dual Rail Power for Signal Chain.}
n _{Buck/Buck, Buck/Boost, Boost/Boost, Boost/Invert,}
Invert/Invert, Buck/Invert
Description
The LT^®8471 is a dual PWM DC/DC converter containing
two internal 2A, 50V switches and an additional 500mA
switch to facilitate step-down and inverting conversion.
Each 2A channel can be independently configured as a
buck, boost, SEPIC, flyback or inverting converter. Ca-
pable of generating positive and negative outputs from a
single input rail, the LT8471 is ideal for many local power
supply designs.
The LT8471 has an adjustable oscillator, set by a resistor
placed from the RT pin to ground. Additionally, the LT8471
can be synchronized to an external clock. The free running
or synchronized switching frequency range of the part can
be set between 100kHz and 2MHz.
Additional features such as frequency foldback, soft-start,
and power good are integrated. The LT8471 is available
in a 20-lead TSSOP package.
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
6V to 32V to ±5V, Dual DC/DC Converter
1µF
1µF
V_IN1
V_IN2
SHOUT
10µH
E1
6V TO 32V
2.2µF
C1
2.2µF
316k
FB1
59k
15µH
LT8471
GND
C3
475k
59k
OV/UV
FB2
100k
PG1
100k
PG2
C2
316k
E2
10µH
SS1 SS2 SYNC RT
2.2µF
0.1µF
0.1µF
187k
8471 TA01a
V_OUT1
5V
1.5A
47µF
×2
47µF
×2
V_OUT2
–5V
0.65A
For more information www.linear.com/8471
Efficiency and Power Loss
Load from V_OUT1 to V_OUT2
90
4
80
70
EFFICIENCY
3
60
50
POWER LOSS
2
40
30
20
V_CC =
1
6V
10
18V
32V
0
0
0
0.2
0.4
0.6
0.8
1.0
LOAD CURRENT (A)
8471 F10b
8471fc
1