LTC3374A
High Accuracy 8-Channel
Parallelable 1A Buck DC/DCs
Features
Description
nn 8-Channel 1A Independent Step-Down DC/DCs
nn Master-Slave Configurable for Up to 4A of Output
Current with a Single Inductor
nn Independent VIN Supplies for Each DC/DC
(2.25V to 5.5V)
nn All DC/DCs Have 0.8V to VIN Output Range
nn ±1% VFB Accuracy, for Buck 1 (1A to 4A)
nn ±1% PGOOD Accuracy
nn Precision Enable Pin Thresholds for Autonomous
Sequencing
nn 1MHz to 3MHz Programmable/Synchronizable
Oscillator Frequency (2MHz Default)
nn Die Temperature Monitor Output
nn Thermally Enhanced 38-Lead 5mm × 7mm QFN and
TSSOP Packages
nn Pin-Compatible with LTC3374
Applications
nn General Purpose Multichannel Power Supplies
nn Industrial/Automotive/Communications
The LTC®3374A is a multioutput power supply IC consisting
of eight synchronous 1A buck converters, all powered from
independent 2.25V to 5.5V input supplies. An upgraded
pin-compatible version of the LTC3374, the LTC3374A,
has higher efficiency, improved output voltage accuracy
and an added overvoltage (OV) indicator.
The DC/DCs may be used independently or in parallel to
achieve higher output currents of up to 4A with a shared
inductor. The common buck switching frequency may be
programmed with an external resistor, synchronized to an
external oscillator, or set to a default internal 2MHz clock.
The operating mode for all DC/DCs may be programmed
via the MODE pin.
To reduce input noise the buck converters are phased in
90° steps. Precision enable pin thresholds simplify power-
up sequencing. The LTC3374A is available in a 38-lead
5mm × 7mm QFN package as well as a 38-lead exposed
pad TSSOP package.
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
Typical Application
Eight Synchronous 1A Buck Regulators
2.25V TO 5.5V
VIN1
SW1
EN1
FB1
BUCK 1
0.8V TO VIN1
UP TO 1A
2.25V TO 5.5V
VIN2
SW2
EN2
FB2
THE EIGHT BUCKS CAN
BE CONFIGURED IN 15
DIFFERENT MASTER/SLAVE
COMBINATIONS
••
•
LTC3374A
••
•
2.25V TO 5.5V
VIN8
SW8
2.7V TO 5.5V
EN8
FB8
VCC
MODE
SYNC
PGOOD_ALL
RT
TEMP
GND
3374A TA01a
BUCK 2
0.8V TO VIN2
UP TO 1A
BUCK 8
0.8V TO VIN8
UP TO 1A
100
90
80
70
60
50
40
30
20
10
0
1m
Buck Efficiency vs ILOAD
fOSC = 1MHz
VOVUITN==13..83VV
VOUT = 1.8V
Burst Mode OPERATION
1A BUCK, L = 4.7µH, L DCR = 40mΩ
2A BUCK, L = 2.2µH, L DCR = 13mΩ
3A BUCK, L = 1.8µH, L DCR = 10mΩ
4A BUCK, L = 1.0µH, L DCR = 8mΩ
10m
100m
LOAD CURRENT (A)
1
4
3374A TA01b
For more information www.linear.com/LTC3374A
3374af
1
