LT8616_15 Datasheet, PDF (1/24 Pages) Linear Technology – Dual 42V Synchronous Monolithic Step-Down Regulator with 6.5A Quiescent Current

LT8616
Features
Dual 42V Synchronous
Monolithic Step-Down Regulator
with 6.5µA Quiescent Current
Description
n _{Wide Input Voltage Range: 3.4V to 42V}
n _{2.5A and 1.5A Buck Regulators with Separate Inputs}
n _{Fast Minimum Switch On-Time: 35ns}
n _{Ultralow Quiescent Current Burst Mode}^® _Operation:
n _{6.5µA IQ Regulating 12VIN to 5VOUT and 3.3VOUT}
n _{Output Ripple < 15mV}
n _{180° Out of Phase Switching}
n _{Adjustable and Synchronizable: 200kHz to 3MHz}
n _{Accurate 1V Enable Pin Thresholds}
n _{Internal Compensation}
n _{Output Soft-Start and Tracking}
n _{TSSOP Package: Output Stays at or Below Regulation}
Voltage During Adjacent Pin Short or When a Pin Is
Left Floating
n _{Thermally Enhanced 28-Lead TSSOP Package}
Applications
n _{Automotive and Industrial Supplies}
n _{General Purpose Step-Down}
The LT^®8616 is a high efficiency, high speed, dual synchro-
nous monolithic step-down switching regulator that con-
sumes only 6.5µA of quiescent current with both channels
enabled. Both channels contain all switches and necessary
circuitry to minimize the need for external components.
Low ripple Burst Mode operation enables high efficiency
down to very low output currents while minimizing output
ripple. A SYNC pin allows synchronization to an external
clock. Internal compensation with peak current mode
topology allows the use of small inductors and results in
fast transient response and good loop stability. The en-
able pins have accurate 1V thresholds and can be used to
program undervoltage lockout. Capacitors on the TR/SS
pins programs the output voltage ramp rate during start-
up while the PG pins signal when each output is within
10% of the programmed output voltage. The LT8616 is
available in a TSSOP package for high reliability.
L, LT, LTC, LTM, Burst Mode, 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, 3.3V, 700kHz Step-Down Converter
V_IN
12V
V_IN1
BOOST1
4.7µF
EN/UV1
4.7µF
1M
10nF
1µF
56.2k
V_IN2
SW1
EN/UV2
FB1
LT8616
PG1
PG2
SYNC/MODE ^BIAS
BOOST2
TR/SS1
TR/SS2
INTV_CC
SW2
RT _GND FB2
0.1µF
10µH
1M
187k
0.1µF
4.7µH
1M
316k
5.6pF
V_OUT1
5V, 1.5A
47µF
10pF
V_OUT2
3.3V, 2.5A
2 x 47µF
8616 TA01a
100
90
80
70
60
50
40
30
0.01 0.1
Efficiency
V_IN1 = V_IN2 = 12V
f_SW = 700kHz
CH1, 5V_OUT
CH2, 3.3V_OUT
1
10 100 1000
LOAD (mA)
8616 TA01b
8616f
For more information www.linear.com/LT8616
1